Realistic Total-Body J-PET Geometry Optimization--Monte Carlo Study
J. Baran, W. Krzemień, L. Raczyński, M. Bała, A. Coussat, S. Parzych, N. Chug, E. Czerwiński, C. Oana Curceanu, M. Dadgar, K. Dulski, K. Eliyan, J. Gajewski, A. Gajos, B. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, G. Korcyl, T. Kozik, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. Stępień, F. Tayefiardebili, K. Tayefiardebili, W. Wiślicki, P. Moskal
abstract
Total-Body PET imaging is one of the most promising newly introduced modalities in the medical diagnostics. State-of-the-art PET scanners use inorganic scintillators such as L(Y)SO or BGO, however, those technologies are very expensive, prohibitng the broad total-body PET applications. We present the comparative studies of performance characteristics of the cost-effective Total-Body PET scanners using Jagiellonian PET (J-PET) technology that is based on plastic scintillators. Here, we investigated in silico five realistic Total-Body scanner geometries, varying the number of rings, scanner radius, and distance between the neighbouring rings. Monte Carlo simulations of two NEMA phantoms (2-meter sensitivity line source and image quality) and the anthropomorphic XCAT phantom, were used to assess the performance of the tested geometries. We compared the sensitivity profiles and we performed the quantitative analysis of the reconstructed images by using the quality metrics such as contrast recovery coefficient, background variability and root mean squared error. The optimal scanner design was selected for the first Total-Body J-PET scanner configuration.
Positronium image of the human brain in vivo
P. Moskal, J. Baran, S. Bass, J. Choiński, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, M. Das, K. Dulski, K.V. Eliyan, K. Fronczewska, A. Gajos, K. Kacprzak, M. Kajetanowicz, T. Kaplanoglu, Ł. Kapłon, K. Klimaszewski, M. Kobylecka, G. Korcyl, T. Kozik, W. Krzemień, K. Kubat, D. Kumar, J. Kunikowska, J. Mączewska, W. Migdał, G. Moskal, W. Mryka, S. Niedźwiecki, S. Parzych, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, F. Tayefi, K. Tayefi, P. Tanty, W. Wiślicki, L. Królicki, E. Ł. Stępień
abstract
Positronium is abundantly produced within the molecular voids of a patient?s body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.
Feasibility of the J-PET to monitor range oftherapeutic proton beams
J. Baran, D. Borys, K. Brzeziński, J. Gajewski, M. Silarski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K.V. Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopeć, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A.J. Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, M. Simbarashe, S. Sharma, Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E.Ł. Stępień, K. Tayefi, F. Tayefi, D.C. Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Ruciński
abstract
Objective: The aim of this work is to investigate the feasibility of the JagiellonianPositron Emission Tomography (J-PET) scanner for intra-treatment proton beamrange monitoring. Approach: The Monte Carlo simulation studies with GATE and PET imagereconstruction with CASToR were performed in order to compare six J-PET scannergeometries (three dual-heads and three cylindrical). We simulated proton irradiationof a PMMA phantom with a Single Pencil Beam (SPB) and Spread-Out BraggPeak (SOBP) of various ranges. The sensitivity and precision of each scanner werecalculated, and considering the setup?s cost-effectiveness, we indicated potentiallyoptimal geometries for the J-PET scanner prototype dedicated to the proton beamrange assessment. Main results: The investigations indicate that the double-layer cylindrical andtriple-layer double-head configurations are the most promising for clinical application.We found that the scanner sensitivity is of the order of 10?5coincidences per primaryproton, while the precision of the range assessment for both SPB and SOBP irradiationplans was found below 1 mm. Among the scanners with the same number of detectormodules, the best results are found for the triple-layer dual-head geometry. Significance: We performed simulation studies demonstrating that the feasibilityof the J-PET detector for PET-based proton beam therapy range monitoring ispossible with reasonable sensitivity and precision enabling its pre-clinical tests in theclinical proton therapy environment. Considering the sensitivity, precision and cost-effectiveness, the double-layer cylindrical and triple-layer dual-head J-PET geometryconfigurations seem promising for the future clinical application. Experimental testsare needed to confirm these findings.
Feasibility studies for imaging e+e- annihilation with modular multi-strip detectors
S. Sharma, L. Povolo, S. Mariazzi, G. Korcyl, K. Kacprzak, D. Kumar, S. Niedzwiecki, J. Baran, E. Beyene, R. S. Brusa, R. Caravita, N. Chug, A. Coussat, C. Curceanu, E. Czerwinski, M. Dadgar, M. Das, K. Dulski, K. Eliyan, A. Gajos, N. Gupta, B. C. Hiesmayr, L. Kaplon, T. Kaplanoglu, K. Klimaszewski, P. Konieczka, T. Kozik, M. K. Kozani, W. Krzemien, S. Moyo, W. Mryka, L. Penasa, S. Parzych, E. Perez Del Rio, L. Raczynski, R. Y. Shopa, M. Skurzok, E. L. Stepien, P. Tanty, F. Tayefi, K. Tayefi, W. Wislicki, P. Moskal
abstract
Studies based on imaging the annihilation of the electron (e-) and its antiparticle positron (e+) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the direct conversion of ee into photons and the formation of their atomically bound state, the positronium atom (Ps), which can be used as a probe for fundamental studies. With the ability to produce large quantities of Ps, manipulate them in long-lived Ps states, and image their annihilations after a free fall or after passing through atomic interferometers, this purely leptonic antimatter system can be used to perform inertial sensing studies in view of a direct test of Einstein equivalence principle. It is envisioned that modular multistrip detectors can be exploited as potential detection units for this kind of studies. In this work, we report the results of the first feasibility study performed on a e beamline using two detection modules to evaluate their reconstruction performance and spatial resolution for imaging ee annihilations and thus their applicability for gravitational studies of Ps.
Comparison of readout systems for high-rate silicon photomultiplier applications
M. L. Wong, M. Kołodziej, K. Briggl, R. Hetzel, G. Korcyl, R. Lalik, A. Malige, A. Magiera, G. Ostrzołek, K. Rusiecka, A. Stahl, V. Urbanevych, M. Wiebusch, A. Wrońska
abstract
Recent years have shown an increased use of silicon photomultipliers (SiPM) in experimentsas they are of reasonable cost, have relatively low power consumption and are easily available in avariety of form factors allowing for a large number of readout channels. At the same time, experimentsare generating data at increasingly high rates requiring the use of more efficient readout systems. Inthis work, the dead time, efficiency, dynamic range, coincidence time resolution and energy resolutionof five different readout systems at various stages of maturity are evaluated to determine the bestsystem for acquiring data from a detector in a high rate experiment. Additional functionalities ofthe systems are also discussed.
Discrete symmetries tested at 10^-4 precision using linear polarization of photons from positronium annihilations
P. Moskal, E. Czerwiński, J. Raj, S. D. Bass, E. Beyene, N. Chug, A. Coussat, C. Curceanu, M. Dadgar, M. Das, K. Dulski, A. Gajos, M. Gorgol, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, T. Kaplanoglu, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Moyo, W. Mryka, S. Niedźwiecki, S. Parzych, E. Pérez del Río, L. Raczyński, S. Sharma, S. Choudhary, R. Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, P. Tanty, F. T. Ardebili, K. T. Ardebili, K. V. Eliyan, W. Wiślicki
abstract
Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of 10^-4 signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation.
Exploration of simultaneous dual-isotope imaging with multi-photon modular J-PET scanner
Ermias Yitayew Beyene, Manish Das, Martyna Durak-Kozica, Grzegorz Korcyl, Wiktor Mryka, Szymon Niedźwiecki, Szymon Parzych, Keyvan Tayefi Ardebili, Rafał Walczak, Kamil Wawrowicz, Ewa Stępień, Paweł Moskal
abstract
The modular J-PET scanner, comprising 24 compact and versatile modules, each consisting of 13 plastic strips with four SiPM detectors at the ends, represents a powerful tool for clinical applications in nuclear medical imaging. This study presents preliminary results from the exploration of simultaneous dual-isotope imaging using the modular J-PET system. Our approach involved two isotopes: 68Ge, characterized by a ringlike shape, and 22Na, exhibiting a point-like shape. The imaging was based on double-coincidence and triple-coincidence events. In the double coincidence case, both isotopes contributed comparably, whereas in the triple coincidence case 22Na dominated due to the prompt gamma being emitted with 100% of positron emissions, unlike 68Ga, where the prompt gamma was emitted in only 1.3% of cases after positron emission. In this work we present direct 2? images determined for two-signal events and images for three-signal events, with two signals from annihilation photons and one from a prompt gamma. These results showcase the preliminary findings from simultaneous dual-isotope imaging of 68Ga and 22Na isotopes using the modular J-PET scanner, which will be presented and discussed.
Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators
M. Dadgar, S. Parzych, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Elyan, A. Gajos, B.C. Hiesmayr, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. L. Stępień, F. Tayefi Ardebili, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki and P. Moskal
abstract
Background: Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for
constructing a Total-Body PET scanner based on plastic scintillators.
Methods: For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configuration (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), the different cross-sections of plastic scintillator, and the multiple numbers of the
plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm.
Results: With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance (? 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body
with additional gain on its sides and provides the possibility for high-quality brain
imaging.
Conclusion: Taking into account not only the sensitivity but also the price of the Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.
Transformation of PET raw data into images for event classification using convolutional neural networks
P. Konieczka, L. Raczyński, W. Wiślicki, O. Fedoruk, K. Klimaszewski, P. Kopka, W. Krzemień, R.Y. Shopa, J. Baran, A. Coussat, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, G. Korcyl, T. Kozik, D. Kumar, S. Niedźwiecki, S. Parzych, E. Pérez del Río, S. Sharma, S. Shivani, M. Skurzok, E.Ł. Stępień, F. Tayefi, P. Moskal
abstract
In positron emission tomography (PET) studies, convolutional neural networks (CNNs) may be applied directly to the reconstructed distribution of radioactive tracers injected into the patient's body, as a pattern recognition tool. Nonetheless, unprocessed PET coincidence data exist in tabular format. This paper develops the transformation of tabular data into -dimensional matrices, as a preparation stage for classification based on CNNs. This method explicitly introduces a nonlinear transformation at the feature engineering stage and then uses principal component analysis to create the images. We apply the proposed methodology to the classification of simulated PET coincidence events originating from NEMA IEC and anthropomorphic XCAT phantom. Comparative studies of neural network architectures, including multilayer perceptron and convolutional networks, were conducted. The developed method increased the initial number of features from 6 to 209 and gave the best precision results (79.8) for all tested neural network architectures; it also showed the smallest decrease when changing the test data to another phantom.
Detection of range shifts in proton beam therapy using the J-PET scanner: a patient simulation study
K. Brzeziński, J. Baran, D. Borys, J. Gajewski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K.V. Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopeć, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A.J. Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E.Ł. Stępień, K. Tayefi, F. Tayefi, D.C. Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Ruciński
abstract
Objective. The Jagiellonian positron emission tomography (J-PET) technology, based on plastic scintillators, has been proposed as a cost effective tool for detecting range deviations during proton therapy. This study investigates the feasibility of using J-PET for range monitoring by means of a detailed Monte Carlo simulation study of 95 patients who underwent proton therapy at the Cyclotron Centre Bronowice (CCB) in Krakow, Poland. Approach. Discrepancies between prescribed and delivered treatments were artificially introduced in the simulations by means of shifts in patient positioning and in the Hounsfield unit to the relative proton stopping power calibration curve. A dual-layer, cylindrical J-PET geometry was simulated in an in-room monitoring scenario and a triple-layer, dual-head geometry in an in-beam protocol. The distribution of range shifts in reconstructed PET activity was visualized in the beam's eye view. Linear prediction models were constructed from all patients in the cohort, using the mean shift in reconstructed PET activity as a predictor of the mean proton range deviation. Main results. Maps of deviations in the range of reconstructed PET distributions showed agreement with those of deviations in dose range in most patients. The linear prediction model showed a good fit, with coefficient of determination r2 = 0.84 (in-room) and 0.75 (in-beam). Residual standard error was below 1 mm: 0.33 mm (in-room) and 0.23 mm (in-beam). Significance. The precision of the proposed prediction models shows the sensitivity of the proposed J-PET scanners to shifts in proton range for a wide range of clinical treatment plans. Furthermore, it motivates the use of such models as a tool for predicting proton range deviations and opens up new prospects for investigations into the use of intra-treatment PET images for predicting clinical metrics that aid in the assessment of the quality of delivered treatment.
Comparative studies of plastic scintillator strips with high technical attenuation length for the total-body J-PET scanner
Ł. Kapłon, J. Baran, N. Chug, A. Coussat, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, B. Hiesmayr, E. Kavya Valsan, K. Klimaszewski, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, G. Moskal, S. Niedźwiecki, D. Panek, S. Parzych, E. Pérez del Rio, L. Raczyński, A. Ruciński, S. Sharma, S. Shivani, R. Shopa, M. Silarski, M. Skurzok, E. Stępień, F. Tayefi Ardebili, K. Tayefi Ardebili, W. Wiślicki, P. Moskal
abstract
Plastic scintillator strips are considered as one of the promising solutions for the cost-effective construction of total-body positron emission tomography, (PET) system. The purpose of the performed measurements is to compare the transparency of long plastic scintillators with dimensions 6 mm x 24 mm x 1000 mm and with all surfaces polished. Six different types of commercial, general purpose, blue-emitting plastic scintillators with low attenuation of visible light were tested, namely: polyvinyl toluene-based BC-408, EJ-200, RP-408, and polystyrene-based Epic, SP32 and UPS-923A. For determination of the best type of plastic scintillator for total-body Jagiellonian positron emission tomograph (TB-J-PET) construction, emission and transmission spectra, and technical attenuation length (TAL) of blue light-emitting by the scintillators were measured and compared. The TAL values were determined with the use of UV lamp as excitation source, and photodiode as light detector. Emission spectra of investigated scintillators have maxima in the range from 420 nm to 429 nm. The BC-408 and EJ-200 have the highest transmittance values of about 90% at the maximum emission wavelength measured through a 6 mm thick scintillator strip and the highest technical attenuation length reaching about 2000 mm, allowing assembly of long detection modules for time-of-flight (TOF) J-PET scanners. Influence of the 6 mm × 6 mm, 12 mm × 6 mm, 24 mm × 6 mm cross-sections of the 1000 mm long EJ-200 plastic scintillator on the TAL and signal intensity was measured. The highest TAL value was determined for samples with 24 mm × 6 mm cross-section.
Efficiency determination of J-PET: first plastic scintillators-based PET scanner
S. Sharma, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, N. Gupta-Sharma, B. C. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, Sz. Niedźwiecki, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, Shivani, R. Y. Shopa, M. Skurzok, E. Ł. Stępień, F. Tayefi, K. Tayefi , W. Wiślicki and P. Moskal
abstract
Background:
The Jagiellonian Positron Emission Tomograph is the 3-layer prototype
of the first scanner based on plastic scintillators, consisting of 192 half-metre-long strips with readouts at both ends. Compared to crystal-based detectors, plastic scintillators
are several times cheaper and could be considered as a more economical alternative to crystal scintillators in future PETs. JPET is also a first multi-photon PET prototype. For the development of multi-photon detection, with photon characterized by the continuous energy spectrum, it is important to estimate the efficiency of J-PET as a function of energy deposition. The aim of this work is to determine the registration efficiency of the J-PET tomograph as a function of energy deposition by incident photons and the intrinsic efficiency of the J-PET scanner in detecting photons of different incident energies. In this study, 3-hit events are investigated, where 2-hits are caused by 511 keV
photons emitted in e+e- annihilations, while the third hit is caused by one of the scattered photons. The scattered photon is used to accurately measure the scattering angle and thus the energy deposition. Two hits by a primary and a scattered photon are sufficient to calculate the scattering angle of a photon, while the third hit ensures
the precise labeling of the 511 keV photons.
Results:
By comparing experimental and simulated energy distribution spectra, the registration efficiency of the J-PET scanner was determined in the energy deposition range of 70-270 keV, where it varies between 20 and 100%. In addition, the intrinsic efficiency of the J-PET was also determined as a function of the energy of the incident photons.
Conclusion:
A method for determining registration efficiency as a function of energy deposition and intrinsic efficiency as a function of incident photon energy of the J-PET scanner was demonstrated. This study is crucial for evaluating the performance of the scanner based on plastic scintillators and its applications as a standard and multi-photon PET systems. The method may be also used in the calibration of Compton-cameras developed for the ion-beam therapy monitoring and simultaneous multi-radionuclide imaging in nuclear medicine.
J-PET detection modules based on plastic scintillators for performing studies with positron and positronium beams
S. Sharma, J. Baran, R.S. Brusa, R. Caravita, N. Chug, A. Coussat, C. Curceanu, E. Czerwinski, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, L. Kaplon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemien D. Kumar, S. Mariazzi, S. Niedźwiecki, L. Panasa, S. Parzych, L. Povolo, E. Perez del Rio, L. Raczynski Shivani, R.Y. Shopa, M. Skurzok, E.L. Stepien, F. Tayefi, K. Tayefi, W. Wislicki and P. Moskal
abstract
The J-PET detector, which consists of inexpensive plastic scintillators, has demonstrated its potential in the study of fundamental physics. In recent years, a prototype with 192 plastic scintillators arranged in 3 layers has been optimized for the study of positronium decays. This allows performing precision tests of discrete symmetries (C, P, T) in the decays of positronium atoms. Moreover, thanks to the possibility of measuring the polarization direction of the photon based on Compton scattering, the predicted entanglement between the linear polarization of annihilation photons in positronium decays can also be studied. Recently, a new J-PET prototype was commissioned, based on a modular design of detection units. Each module consists of 13 plastic scintillators and can be used as a stand-alone, compact and portable detection unit. In this paper, the main features of the J-PET detector, the modular prototype and their applications for possible studies with positron and positronium beams are discussed. Preliminary results of the first test experiment performed on two detection units in the continuous positron beam recently developed at the Antimatter Laboratory (AML) of Trento are also reported.
TOF MLEM Adaptation for the Total-Body J-PET with a Realistic Analytical System Response Matrix
R.Y. Shopa, J. Baran, K. Klimaszewski, W. Krzemień, L. Raczyński, W. Wiślicki, K. Brzeziński, N. Chug, A. Coussat, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, B.C. Hiesmayr, E. Kavya Valsan, G. Korcyl, T. Kozik, D. Kumar, Ł. Kapłon, G. Moskal, S. Niedźwiecki, D. Panek, S. Parzych, E. Pérez del Rio, A. Ruciński, S. Sharma, Shivani, M. Silarski, M. Skurzok, E. Stepień, F. Tayefi Ardebili, K. Tayefi Ardebili, P. Moskal
abstract
We report a study of the original image reconstruction algorithm based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM), developed for the total-body (TB) Jagiellonian PET (J-PET) scanners. The method is applicable to generic cylindrical or modular multi-layer layouts and is extendable to multi-photon imaging. The system response matrix (SRM) is represented as a set of analytical functions, uniquely defined for each pair of plastic scintillator strips used for the detection. A realistic resolution model (RM) in detector space is derived from fitting the Monte Carlo simulated emissions and detections of annihilation photons on oblique transverse planes. Additional kernels embedded in SRM account for TOF, parallax effect and axial smearing. The algorithm was tested on datasets, simulated in GATE for the NEMA IEC and static XCAT phantoms inside a 24-module 2-layer TB J-PET. Compared to the reference TOF MLEM with none or a shift-invariant RM, an improvement was observed, as evaluated by the analysis of image quality, difference images and ground truth metrics. We also reconstructed the data with additive contributions, pre-filtered geometrically and with non-TOF scatter correction applied. Despite some deterioration, the obtained results still capitalise on the realistic RM with better edge preservation and superior ground truth metrics. The envisioned prospects of the TOF MLEM with analytical SRM include its application in multi-photon imaging and further upgrade to account for the non-collinearity, positron range and other factors.
Investigation of novel preclinical Total Body PET designed with J-PET technology: A simulation study
M. Dadgar, S. Parzych, F. Tayefi Ardebili, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, R.Y. Shopa, M. Skurzok, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki, E.Ł. Stępień, P. Moskal
abstract
The growing interest in human-grade Total Body PET systems has also application in small animal research. Due to the existing limitations in human-based studies involving drug development and novel treatment monitoring, animalbased research became a necessary step for testing and protocol preparation. In this simulation-based study two unconventional, cost effective small animal Total Body PET scanners (for mouse and rat studies) have been investigated in order to inspect their feasibility for preclinical research. They were designed with the novel technology explored by the Jagiellonian PET Collaboration (J-PET). Two main PET characteristics: sensitivity and spatial resolution were mainly inspected to evaluate their performance. Moreover, the impact of the scintillator dimension and time-offlight on the latter parameter were examined in order to design the most efficient tomographs. The presented results show that for mouse TB J-PET the achievable system sensitivity is equal to 2.35% and volumetric spatial resolution to 9.46 +- 0.54 mm3, while for rat TB J-PET they are equal to 2.6% and 14.11 ? 0.80 mm3, respectively. Furthermore, it was shown that the designed tomographs are almost parallax-free systems, hence they resolve the problem of the acceptance criterion trade-off between enhancing spatial resolution and reducing sensitivity.
ProTheRaMon - a GATE simulation framework for proton therapy range monitoring using PET imaging
D. Borys, J. Baran, K.W. Brzezinski, J. Gajewski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K. Valsan Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopec, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A. John Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Pérez del Río, L. Raczyński, S. Sharma, S. Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E. Stępień, K. Tayefi Ardebili, F. Tayefi, D. Charles Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Rucinski
abstract
Objective: This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland. Approach: The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user's needs and specific settings of a given proton therapy facility and PET scanner design. Main results: ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized. Significance: We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github.
Real-Time data processing pipeline for trigger readout board-based data acquisition systems
A. Malige, G. Korcyl, M. Firlej, T. Fiutowski, M. Idzik, B. Korzeniak, R. Lalik, A. Misiak, A. Molenda, J. Moroń, N. Rathod, P. Salabura, K. Świentek, P. Wintz
abstract
Large-scale physics experiments running at high interaction rates place a high demand on the data acquisition system (DAQ) responsible for transporting the data from the detector to the storage. The antiProton ANihilation at DArmstadt (PANDA) at the facility for anti-proton and ion research (FAIR) is one such experiment of the future that will not use fixed hardware triggers; instead, the event selection is based on real-time feature extraction, filtering, and high-level correlations. A firmware framework for such real-time data processing has been developed and tested with hardware setup for a PANDA Forward Tracker (FT) prototype. The solution is applicable for other detector subsystems based on the so-called Trigger Readout Board (TRB) data read-out system.
Positronium imaging with the novel multiphoton PET scanner
P. Moskal, K. Dulski, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, J. Gajewski, A. Gajos, G. Grudzień, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, H. Karimi, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, P. Małczak, S. Niedźwiecki, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński, J. Raj, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E.Ł. Stępień, M. Szczepanek, F. Tayefi, W. Wiślicki
abstract
In vivo assessment of cancer and precise location of altered tissues at initial stages of molecular disorders are important diagnostic challenges. Positronium is copiously formed in the free molecular spaces in the patient?s body during positron emission tomography (PET). The positronium properties vary according to the size of inter- and intramolecular voids and the concentration of molecules in them such as, e.g., molecular oxygen, O2; therefore, positronium imaging may provide information about disease progression during the initial stages of molecular alterations. Current PET systems do not allow acquisition of positronium images. This study presents a new method that enables positronium imaging by simultaneous registration of annihilation photons and deexcitation photons from pharmaceuticals labeled with radionuclides. The first positronium imaging of a phantom built from cardiac myxoma and adipose tissue is demonstrated. It is anticipated that positronium imaging will substantially
enhance the specificity of PET diagnostics.
Optimisation of the event-based TOF filtered back-projection for online imaging in total-body J-PET
R.Y. Shopa, K. Klimaszewski, P. Kopka, P. Kowalski, W. Krzemień, L. Raczyński, W. Wiślicki, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, D. Kisielewska, G. Korcyl, N. Krawczyk, E. Kubicz, Sz. Niedźwiecki, J. Raj, S. Sharma, Shivani, E.Ł. Stępień, F. Tayefi, P. Moskal
abstract
We perform a parametric study of the newly developed time-of-flight (TOF) image reconstruction algorithm, proposed for the real-time imaging in total-body Jagiellonian PET (J-PET) scanners. The asymmetric 3D filtering kernel is applied at each most likely position of electron-positron annihilation, estimated from the emissions of back-to-back gamma-photons. The optimisation of its parameters is studied using Monte Carlo simulations of a 1-mm spherical source, NEMA IEC and XCAT phantoms inside the ideal J-PET scan- ner. The combination of high-pass filters which included the TOF filtered back-projection (FBP), resulted in spatial resolution, 1.5 times higher in the axial direction than for the conventional 3D FBP. For real- istic 10-minute scans of NEMA IEC and XCAT, which require a trade-offbetween the noise and spatial resolution, the need for Gaussian TOF kernel components, coupled with median post-filtering, is demon- strated. The best sets of 3D filter parameters were obtained by the Nelder-Mead minimisation of the mean squared error between the resulting and reference images. The approach allows training the recon- struction algorithm for custom scans, using the IEC phantom, when the temporal resolution is below 50 ps. The image quality parameters, estimated for the best outcomes, were systematically better than for the non-TOF FBP.
Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography
P. Moskal, A. Gajos, M. Mohammed, J. Chhokar, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, M. Gorgol, J. Goworek, B. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, S. Niedźwiecki, S. Parzych, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, S. Sharma, S. Choudhary, R. Shopa, A. Sienkiewicz, M. Silarski, M. Skurzok, E. Stepien, F. Tayefi, W. Wiślicki
abstract
Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remain scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron-positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by the knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without a magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with a single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10^{-4}, with an over threefold improvement on the previous measurement.
Simulating NEMA characteristics of the modular total-body J-PET scanner - an economic total-body PET from plastic scintillators
P. Moskal, P. Kowalski, R.Y. Shopa, L. Raczyński, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, P. Kopka, G. Korcyl, N. Krawczyk, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, Sz. Parzych, J. Raj, S. Sharma, S. Shivani, E. Stępień, F. Tayefi, W. Wiślicki
abstract
The purpose of the presented research is the estimation of the performance characteristics of the economic total-body Jagiellonian-PET system (TB-J-PET) constructed from plastic scintillators. The characteristics are estimated according to the NEMANU-2-2018 standards utilizing the GATE package. The simulated detector consists of 24 modules, each built out of 32 plastic scintillator strips
(each with a cross-section of 6 mm times 30 mm and length of 140 or 200 cm) arranged in two layers in regular 24-sided polygon circumscribing a circle with a diameter of 78.6 cm. For the TB-J-PET with an axial field-of-view (AFOV) of 200 cm, a spatial resolution (SRs) of 3.7mm (transversal) and 4.9mm (axial) are achieved. The noise equivalent count rate (NECR) peak of 630 kcps is expected at 30 kBq cc^-1. Activity concentration and the sensitivity at the center amount to 38 cps kBq^-1. The scatter fraction (SF) is estimated to 36.2 %. The values of SF and SR are comparable to those obtained for the state-of-the-art clinical PET scanners and the first total-body tomographs: uExplorer and PennPET.With respect to the standard PET systemswithAFOVin the range from16 to 26 cm, the TBJ-PET is characterized by an increase inNECRapproximately by a factor of 4 and by the increase of the whole-body sensitivity by a factor of 12.6 to 38. The time-of-flight resolution for the TB-J-PETis expected to be at the level ofCRT=240 ps fullwidth at half-maximum. For the TB-J-PETwith an AFOVof 140 cm, an image quality of the reconstructed images of a NEMAIEC phantom was presented with a contrast recovery coefficient and a background variability parameters. The increase of the whole-body sensitivity andNECRestimated for the TB-J-PET with respect to current commercial PETsystems makes the TB-J-PET a promising cost-effective solution for the broad clinical applications of total-body PET scanners. TB-J-PETmay constitutes an economic alternative for the crystal TB-PET scanners, since plastic scintillators are much cheaper than BGO or LYSO crystals and the axial arrangement of the strips significantly reduces the costs of readout electronics and SiPMs.
The J-PET detector - a tool for precision studies of ortho-positronium decays
K. Dulski, S.D. Bass, J. Chhokar, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B.C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K. Klimaszewski, P. Kopka, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, P. Małczak, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński7, J. Raj, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, F. Tayefi, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The J-PET tomograph is constructed from plastic scintillator strips arranged axially in concentric cylindrical layers. It enables investigations of positronium decays by measurement of the time, position, polarization and energy deposited by photons in the scintillators, in contrast to studies conducted so far with crystal and semiconductor based detection systems where the key selection of events is based on the measurement of the photons energies. In this article we show that the J-PET tomography system constructed solely from plastic scintillator detectors is capable of exclusive measurements of the decays of ortho-positronium atoms. We present the first positronium production results and its lifetime distribution measurements. The obtained results prove the capability of the J-PET tomograph for (i) fundamental studies of positronium decays (in particular test of discrete symmetries in purely leptonic systems), (ii) positron annihilation lifetime spectroscopy, as well as (iii) molecular imaging diagnostics and (iv) observation of entanglement
PANDA Phase One
G. Barucca, ..., G. Korcyl, R. Lalik, A. Malige, P. Moskal , K. Nowakowski , W. Przygoda , N. Rathod , P. Salabura , J. Smyrski , et al.
abstract
The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P(anti)P PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton-nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup.The physics programme that is achievable during Phase One is outlined in this paper.
The potential of Lambda and Xi- studies with PANDA at FAIR
G. Barucca, F. Davi, G. Lancioni, P. Mengucci, L. Montalto, P. P. Natali, N. Paone, D. Rinaldi, L. Scalise, W. Erni, B. Krusche, M. Steinacher, N. Walford, N. Cao, Z. Liu, C. Liu, B. Liu, X. Shen, S. Sun, J. Tao, X. A. Xiong, G. Zhao, J. Zhao, M. Albrecht, W. Alkakhi, S. Bökelmann, F. Feldbauer, M. Fink, J. Frech, V. Freudenreich, M. Fritsch, R. Hagdorn, F. H. Heinsius, T. Held, T. Holtmann, I. Keshk, H. Koch, B. Kopf, M. Kuhlmann, M. Kümmel, M. Küßner, J. Li, A. Mustafa, M. Pelizäus, A. Pitka, J. Reher, G. Reicherz, M. Richter, C. Schnier, L. Sohl, M. Steinke, T. Triffterer, C. Wenzel, U. Wiedner, H. Denizli, N. Er, R. Beck, C. Hammann, J. Hartmann, B. Ketzer, J. Müllers, M. Rossbach, B. Salisbury, C. Schmidt, U. Thoma, M. Urban, A. Bianconi, M. Bragadireanu, D. Pantea, M. Domagala, G. Filo, E. Lisowski, F. Lisowski, M. Michałek, P. Poznański, J. Płażek, K. Korcyl, A. Kozela, P. Lebiedowicz, K. Pysz, W. Schäfer, A. Szczurek, T. Fiutowski, M. Idzik, K. Swientek, P. Terlecki, G. Korcyl, R. Lalik, A. Malige, P. Moskal, K. Nowakowski, W. Przygoda, N. Rathod, Z. Rudy, P. Salabura, J. Smyrski, I. Augustin, R. Böhm, I. Lehmann, L. Schmitt, V. Varentsov, M. Al-Turany, A. Belias, H. Deppe, R. Dzhygadlo, H. Flemming, A. Gerhardt, K. Götzen, A. Heinz, P. Jiang, R. Karabowicz, S. Koch, U. Kurilla, D. Lehmann, J. Lühning, U. Lynen, H. Orth, K. Peters, J. Rieger, T. Saito, G. Schepers, C. J. Schmidt, C. Schwarz, J. Schwiening, A. Täschner, M. Traxler, B. Voss, P. Wieczorek, V. Abazov, G. Alexeev, V. A. Arefiev, V. Astakhov, M. Yu. Barabanov, B. V. Batyunya, V. Kh. Dodokhov, A. Efremov, A. Fechtchenko, A. Galoyan, G. Golovanov, E. K. Koshurnikov, Y. Yu. Lobanov, A. G. Olshevskiy, A. A. Piskun, A. Samartsev, S. Shimanski, N. B. Skachkov, A. N. Skachkova, E. A. Strokovsky, V. Tokmenin, V. Uzhinsky, A. Verkheev, A. Vodopianov, N. I. Zhuravlev, D. Branford, D. Watts, M. Böhm, W. Eyrich, A. Lehmann, D. Miehling, M. Pfaffinger, N. Quin, L. Robison, K. Seth, T. Xiao, D. Bettoni, A. Ali, A. Hamdi, M. Himmelreich, M. Krebs, S. Nakh
abstract
he antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p(anti)p -> Lambda(anti)Lambda and p(anti)p -> anti(Xi)+Xi-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
Feasibility studies for the measurement of time-like proton electromagnetic form factors from pp->m+m- at PANDA at FAIR
G. Barucca, ..., G. Korcyl, P. Moskal et al.
abstract
This paper reports on Monte Carlo simulation results for future measurements of time-like proton electromagnetic form factors, |GE| and |GM|, using the pp?m+m- reaction at PANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at PANDA, using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is pp->pi+pi-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.
Directed, elliptic and higher order flow harmonics of protons, deuterons and tritons in Au+Au collisions at sqrt(s_NN) = 2.4 GeV
J. Adamczewski-Musch, ...., G. Korcyl, ...., R. Lalik, ..., A. Malige, ...K. Nowakowski,...., W. Przygoda,...K. Pysz, ..., N. Rathod, ...,P. Salabura, .., U. Singh, J. Smyrski, et al
abstract
Flow coefficients vn of the orders n = 1 - 6 are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons as a function of centrality, transverse momentum and rapidity in Au+Au collisions at sqrt(s_NN) = 2.4 GeV. Combining the information from the flow coefficients of all orders allows to construct for the first time, at collision energies of a few GeV, a complete, multi-differential picture of the emission pattern of these particles. The ratio v4/v22 at mid-rapidity is found to be remarkably close to the value 0.5, as might be indicative for an ideal fluid scenario.
3D TOF-PET image reconstruction using total variation regularization
L. Raczyński, W. Wiślicki, K. Klimaszewski, W. Krzemień, P. Kopka, P. Kowalski, R. Y. Shopa, M. Bała, J. Chhokar, C. Curceanu, E. Czerwinski, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B. Hiesmayr, B. Jasińska, K. Kacprzak, L. Kapłon, D. Kisielewska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, S. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, J. Raj, K. Rakoczy, A. Ruciński, S. Sharma, S. Shivani, M. Silarski, M. Skurzok, E.Ł. Stepień, B. Zgardzińska, P. Moskal
abstract
In this paper we introduce a semi-analytic algorithm for 3-dimensional image reconstruction for positron emission tomography (PET). The method consists of the back-projection of the acquired data into the most likely image voxel according to time-of-flight (TOF) information, followed by the filtering step in the image space using an iterative optimization algorithm with a total variation (TV) regularization. TV regularization in image space is more computationally efficient than usual iterative optimization methods for PET reconstruction with a full system matrix that uses TV regularization. The efficiency comes from the one-time TOF back-projection step that might also be described as a reformatting of the acquired data. An important aspect of our work concerns the evaluation of the filter operator of the linear transform mapping an original radioactive tracer distribution into the TOF back-projected image. We obtain concise, closed-form analytical formula for the filter operator. The proposed method is validated with the Monte Carlo simulations of the NEMA IEC phantom using a one-layer, 50 cm-long cylindrical device called Jagiellonian PET scanner. The results show a better image quality compared with the reference TOF maximum likelihood expectation maximization algorithm.
A simple approach for experimental characterization and validation of proton pencil beam profiles
P. Stasica, J. Baran, C. Granja, N. Krah, G. Korcyl, C. Oancea, M. Pawlik-Niedźwiecka, Sz. Niedźwiecki, M. Rydygier, A. Schavi, A. Rucinski, J. Gajewski
abstract
A precise characterization of therapeutic proton pencil beams is essential for commissioning of any treatment planning system (TPS). The dose profile characterization includes measurement of the beam lateral dose profile in the beam core and far from the beam core, in the so called low-dose envelope, and requires a sophisticated detection system with a few orders of magnitude dynamic range. We propose to use a single-quantum sensitive MINIPIX TIMEPIX detector, along with an in-house designed holder to perform measurements of the pencil beam dose profile in air and in water. We validated the manufacturer calibration of the MINIPIX TIMEPIX detector in proton beams of various energies and compared the deposited energy spectra to Monte Carlo (MC) simulations. The precision of the lateral dose profile measurements has been systematically validated against Krakow proton facility commissioning data and dose profile simulations performed with MC codes GATE/Geant4 and FRED. We obtained an excellent agreement between MINIPIX TIMEPIX measurements and simulations demonstrating the feasibility of the system for a simple characterization and validation of proton pencil beams. The proposed approach can be implemented at any proton therapy facility to acquire experimental data needed to commission and validate analytical and MC based TPS.
Synchronisation and calibration of the 24-modules J-PET prototype with 300 mm axial field of view
P. Moskal, T. Bednarski, Sz. Niedźwiecki, M. Silarski, E. Czerwiński, T. Kozik, J. Chhokar, M. Bała, C. Curceanu, R. Del Grande, M. Dadgar, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K.Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, L. Raczyński, S. Sharma, Shivani, R. Y. Shopa, M. Skurzok, E. Stępień, W. Wiślicki, B. Zgardzińska
abstract
Research conducted in the framework of the J-PET project aims to develop a cost-effective total-body positron emission tomography scanner. As a first step on the way to construct a full-scale J-PET tomograph from long strips of plastic scintillators, a 24-strip prototype was built and tested. The prototype consists of detection modules arranged axially forming a cylindrical diagnostic chamber with an inner diameter of 360 mm and an axial field-of-view of 300 mm. Promising perspectives for a low-cost construction of a total-body PET scanner are opened due to an axial arrangement of strips of plastic scintillators, which have a small light attenuation, superior timing properties, and the possibility of cost-effective increase of the axial field-of-view. The presented prototype comprises dedicated solely digital front-end electronic circuits and a triggerless data acquisition system which required development of new calibration methods including time, thresholds and gain synchronization. The system and elaborated calibration methods including first results of the 24-module J-PET prototype are presented and discussed. The achieved coincidence resolving time equals to CRT = 490 +- 9 ps. This value can be translated to the position reconstruction accuracy s(Dl) = 18 mm which is fairly position-independent Keywords: positron emission tomography, plastic scintillators, J-PET.
Performance assessment of the 2gamma positronium imaging with the total-body PET scanners
P. Moskal, D. Kisielewska, Z. Bura, C. Chhokar, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, A. Kamińska, Ł. Kapłon, H. Karimi, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, P. Małczak, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński, J. Raj, A. Ruciński, S. Sharma, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, S. Vandenberghe, W. Wiślicki, B. Zgardzińska
abstract
In living organisms the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511~keV photons. In this article we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include: (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2gamma annihilations, and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. Simulations are conducted assuming that radiopharmaceutical is labelled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET, and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution the three cases were considered assuming that CRT is equal to 140ps, 50ps and 10ps. The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences is larger by a factor of 12.2 (for LYSO PET) and by factor of 4.7 (for plastic PET) with respect to the sensitivity for the standard 2gamma imaging by LYSO PET scanners with AFOV=20cm.
Estimating relationship between the Time Over Threshold and energy loss by photons in plastic scintillators used in the J-PET scanner
S. Sharma, J. Chhokar, C. Curceanu, E. Czerwinski, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, N. Gupta-Sharma, R. Del Grande, B. C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, H. Karimi, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemien, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Palka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, A. Rucinski, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, E. L. Stepien, W. Wislicki, B. Zgardzinska, P. Moskal
abstract
Time-Over-Threshold (TOT) technique is being used widely due to its implications in developing the multi channel readouts mainly when fast signal processing is required. Using TOT technique as a measure of energy loss instead of charge integration methods significantly reduces the signals readout cost by combining the time and energy information. Therefore, this approach can potentially be used in J-PET tomograph which is build from plastic scintillators characterized by fast light signals. The drawback in adopting this technique is lying in the non-linear correlation between input energy loss and TOT of the signal. The main motivation behind this work is to develop the relationship between TOT and energy loss and validate it with the J-PET tomograph.
The experiment was performed using the 22Na beta emitter source placed in the center of the J-PET tomograph. One can obtain primary photons of two different energies: 511 keV photon from the annihilation of positron (direct annihilation or through the formation of para-Positronim atom or pick-off process of ortho-Positronium atoms), and 1275 keV prompt photon. This allows to study the correlation between TOT values and energy loss for energy range up to 1000 keV. As the photon interacts dominantly via Compton scattering inside the plastic scintillator, there is no direct information of primary photon energy. However, using the J-PET geometry one can measure the scattering angle of the interacting photon. Since, 22Na source emits photons of two different energies, it is required to know unambiguously the energy of incident photons and its corresponding scattering angle for the estimation of energy deposition. In this work, the relationship between Time Over Threshold and energy loss by interacting photons inside the plastic scintillators used in J-PET scanner is established for a energy deposited range 100-1000 keV.
Hit-time and hit-position reconstruction in strips of plastic scintillators using multi-threshold readouts
N. G. Sharma, M. Silarski, J. Chhokar, E. Czerwinski, C. Curceanu, K. Dulski, K. Farbaniec, A. Gajos, R. Del Grande, M. Gorgol, B. C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemien, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Palka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, S. Sharma, S. Shivani, R. Y. Shopa, M. Skurzok, W. Wislicki, B. Zgardzinska, P. Moskal
abstract
In this article a new method for the reconstruction of hit-position and hit-time of photons in long scintillator detectors is investigated. This research is motivated by the recent development of the positron emission tomography scanners based on plastic scintillators. The proposed method constitutes a new way of signal processing in Multi-Voltage-Technique. It is based on the determination of the degree of similarity between the registered signals and the synchronized model signals stored in a library. The library was established for a set of well defined hit-positions along the length of the scintillator. The Mahalanobis distance was used as a measure of similarity between the two compared signals. The method was validated on the experimental data measured using two-strips J-PET prototype with dimensions of 5x9x300 mm. The obtained Time-of-Flight (TOF) and spatial resolutions amount to 325 ps (FWHM) and 25 mm (FWHM), respectively. The TOF resolution was also compared to the results of an analogous study done using Linear Fitting method. The best TOF resolution was obtained with this method at four pre-defined threshold levels which was comparable to the resolution achieved from the Mahalanobis distance at two pre-defined threshold levels. Although the algorithm of Linear Fitting method is much simpler to apply than the Mahalanobis method, the application of the Mahalanobis distance requires a lower number of applied threshold levels and, hence, decreases the costs of electronics used in PET scanner.
J-PET Framework: Software platform for PET tomography data reconstruction and analysis
W. Krzemień, A. Gajos, K. Kacprzak, K. Rakoczy, G. Korcyl
abstract
J-PET Framework is an open-source software platform for data analysis, written in C++ and based on the ROOT package. It provides a common environment for implementation of reconstruction, calibration and filtering procedures, as well as for user-level analyses of Positron Emission Tomography data. The library contains a set of building blocks that can be combined by users with even little programming experience, into chains of processing tasks through a convenient, simple and well-documented API. The generic input-output interface allows processing the data from various sources: low-level data from the tomography acquisition system or from diagnostic setups such as digital oscilloscopes, as well as high-level tomography structures e.g. sinograms or a list of lines-of-response. Moreover, the environment can be interfaced with Monte Carlo simulation packages such as GEANT and GATE, which are commonly used in the medical scientific community.
Towards Lattice Quantum Chromodynamics on FPGA devices
G. Korcyl, P. Korcyl
abstract
In this paper we describe a single-node, double precision Field Programmable Gate Array (FPGA) implementation of the Conjugate Gradient algorithm in the context of Lattice Quantum Chromodynamics. As a benchmark of our proposal we invert numerically the Dirac-Wilson operator on a 4-dimensional grid on three Xilinx hardware solutions: Zynq Ultrascale+ evaluation board, the Alveo U250 accelerator and the largest device available on the market, the VU13P device. In our implementation we separate software/hardware parts in such a way that the entire multiplication by the Dirac operator is performed in hardware, and the rest of the algorithm runs on the host. We find out that the FPGA implementation can offer a performance comparable with that obtained using current CPU or Intel?s many core Xeon Phi accelerators. A possible multiple node FPGA-based system is discussed and we argue that power-efficient High Performance Computing (HPC) systems can be implemented using FPGA devices only.
Feasibility study of the positronium imaging with the J-PET tomograph
P. Moskal, D. Kisielewska, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, B. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, G. Korcyl, P. Kowalski, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E. Stępień, W. Wiślicki, B. Zgardzińska
abstract
A detection system of the conventional PET tomograph is set-up to record data from e+ e- annihilation into two photons with energy of 511 keV, and it gives information on the density distribution of a radiopharmaceutical in the body of the object. In this paper we explore the possibility of performing the three gamma photons imaging based on ortho- positronium annihilation, as well as the possibility of positronium average lifetime imaging with the J-PET tomograph constructed from plastic scintillators. For this purposes simulations of the ortho-positronium formation and its annihilation into three photons were performed taking into account distributions of photons' momenta as predicted by the theory of quantum electrodynamics and the response of the J-PET tomograph. In order to test the proposed ortho-positronium lifetime image reconstruction method, we concentrate on the decay of the ortho-positronium into three photons and applications of radiopharmaceuticals labeled with isotopes emitting a prompt gamma quantum. The proposed method of imaging is based on the determination of hit-times and hit-positions of registered photons which enables the reconstruction of the time and position of the annihilation point as well as the lifetime of the ortho-positronium on an event-by-event basis. We have simulated the production of the positronium in a cylindrical phantom composed of a set of different materials in which the ortho-positronium lifetime varied from 2 ns to ~2.9 ns, as expected for ortho-positronium created in the human body. The presented reconstruction method for total-body J-PET like detector allows to achieve a mean lifetime resolution of about 40 ps. Recent Positron Annihilation Lifetime Spectroscopy measurements of cancerous and healthy uterine tissues show that this sensitivity may allow to study the morphological changes in cell structures.
Simulation studies of annihilation-photon's polarisation via Compton scattering with the J-PET tomograph
N. Krawczyk, B.C. Hiesmayr, J. Chhokar, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
J-PET is the first positron-emission tomograph (PET) constructed from plastic scintillators. It was optimized for the detection of photons from electron-positron annihilation. Such photons, having an energy of 511 keV, interact with electrons in plastic scintillators predominantly via the Compton effect. Compton scattering is at most probable at an angle orthogonal to the electric field vector of the interacting photon. Thus registration of multiple photon scatterings with J-PET enables to determine the polarization of the annihilation photons. In this contribution we present estimates on the physical limitation in the accuracy of the polarization determination of 511 keV photons with the J-PET detector.
Identical pion intensity interferometry in central Au plus Au collisions at 1.23A GeV HADES Collaboration
J. Adamczewski-Musch, O. Arnold, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, R. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, T. Matulewicz, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, S. Morozov, et al.
abstract
We investigate identical pion HBT intensity interferometry in central Au +Au collisions at 1.23A GeV. High-statistics pi(-)pi(-) and pi(+)pi(+) data are measured with HADES at SIS18/GSI. The radius parameters, derived from the correlation function depending on relative momenta in the longitudinally comoving system and parametrized as three-dimensional Gaussian distribution, are studied as function of transverse momentum. A substantial charge-sign difference of the source radii is found, particularly pronounced at low transverse momentum. The extracted source parameters agree well with a smooth extrapolation of the center-of-mass energy dependence established at higher energies, extending the corresponding excitation functions down towards a very low energy. (C) 2019 The Author(s). Published by Elsevier B.V.
Investigating the Dirac Operator Evaluation with FPGAs
G. Korcyl, P. Korcyl
abstract
In recent years, computational capacity of single Field Programmable Gate Array (FPGA) devices as well as their versatility have increased signifcantly. Adding to that fact, the High Level Synthesis frameworks allowing to program such processors in a high-level language like C++, makes modern FPGA devices a serious candidate as building blocks of a general-purpose High Performance Computing solution. In this contribution we describe benchmarks which we performed using a kernel from the Lattice QCD code, a highly compute-demanding HPC academic code for elementary particle simulations on the newest device from Xilinx, the U250 accelerator card. We describe the architecture of our solution and benchmark its performance on a single FPGA device running in two modes: using either external or embedded memory. We discuss both approaches in detail and provide assessment for the necessary memory throughput and the minimal amount of resources needed to deliver optimal performance depending on the available hardware. Our considerations can be used as guidelines for estimating the performance of some larger, manynode systems.
Strong Absorption of Hadrons with Hidden and Open Strangeness in Nuclear Matter
J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, S. Chernenko, L. Chlad, P. Chudoba, I. Ciepal, C. Deveaux, D. Dittert, J. Dreyer, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, F. Kornas, R. Kotte, J. Kubos, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, S. Linev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Malige, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, et al.
abstract
We present the first observation of K- and phi absorption within nuclear matter by means of pi(-)-induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K-/K+)(W)/(K-/K+)(C) is found to be 0.319 +/- 0.009(stat)(-0.012)(+0.014)(syst) indicating a larger absorption of K- in heavier targets as compared to lighter ones. The measured phi/K- ratios in pi(-) + C and pi(-) + W reactions within the HADES acceptance are found to be equal to 0.55 +/- 0.04(stat)(-0.07)(+0.06) (syst) and to 0.63 +/- 0.06(stat)(-0.11)(+0.11)(syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the phi meson in nuclear medium is strongly coupled to the K- dynamics. The large difference in the. production off C and W nuclei is discussed in terms of a strong phi N in-medium coupling. These results are relevant for the description of heavy-ion collisions and the structure of neutron stars.
Sub-threshold production of K-s(0) mesons and Lambda hyperons in Au plus Au collisions at root s(NN)=2.4 GeV
J. Adamczewski-Musch, O. Arnold, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, R. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, R. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kamakov, R. Kotte, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, S. Morozov, et al.
abstract
We present first data on sub-threshold production of K-s(0) mesons and Lambda hyperons in Au+Au collisions at root s(NN) = 2.4 GeV. We observe an universal < A(part)> scaling of hadrons containing strangeness, independent of their corresponding production thresholds. Comparing the yields, their < A(part)> scaling, and the shapes of the rapidity and the p(t) spectra to state-of-the-art transport model (UrQMD, HSD, IQMD) predictions, we find that none of them can simultaneously describe these observables with reasonable chi(2) values. (C) 2019 The Authors. Published by Elsevier B.V.
Technical Design Report for the PANDA Barrel DIRC Detector
B. Singh, ..., B. Kamys, G. Korcyl, W. Krzemien, P. Moskal, et al. (PANDA Collaboration)
abstract
This documents describes the technical design and the expected performance of the Barrel DIRC detector for the PANDA experiment. The Barrel DIRC will provide hadronic charged particle identification in the polar angle range of 22 [deg] to 140 [deg] for particle momenta between 0.5 GeV/c and 3.5 GeV/c. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean pi/K separation with at least 3 standard deviations over the entire phase space of charged kaons in the Barrel DIRC.
Collective flow and correlations measurements with HADES in Au plus Au collisions at 1.23 AGeV
B. Kardan, J. Adamczewski-Musch, O. Arnold, B. Arnoldi-Meadows, A. Belounnas, A. Belyaev, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, L. Chlad, P. Chudoba, I. Ciepal, C. Deveaux, D. Dittert, J. Dreyer, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, A. Gillitzer, O. Golosov, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, V. Ivanov, A. Ivashkin, B. Kampfer, M. Kajetanowicz, KH. Kampert, B. Kardan, V. Khomyakov, I. Koenig, W. Koenig, G. Korcyl, G. Kornakov, F. Kornas, R. Kotte, A. Kozela, J. Kubos, A. Kugler, T. Kunz, P. Kurilkin, V. Kushpil, V. Ladygin, R. Lalik, A. Lebedev, S. Linev, L. Lopes, M. Lorenz, G. Lykasov, T. Mahmoud, A. Malakhov, J. Markert, S. Maurus, et al.
abstract
The HADES experiment provides a large acceptance combined with a high mass resolution and therefore makes it possible to study dielectron and hadron production in heavy-ion collisions with unprecedented precision. With the high statistics of seven billion Au+Au collisions at 1.23 AGeV recorded in 2012 the investigation of collective effects and particle correlations is possible with unprecedented accuracy. We present multi-differential data on directed (v(1)) and elliptic (v(2)) flow, and the first measurement of triangular flow (v(3)), of protons and deuterons.
Multi-differential pattern of low-mass e(+)e(-) excess from root S-NN=2.4 GeV Au+Au collisions with HADES
S. Harabasz, J. Adamczewski-Musch, O. Arnold, B. Arnoldi-Meadows, A. Belounnas, A. Belyaev, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, L. Chlad, P. Chudoba, I. Ciepal, C. Deveaux, D. Dittert, J. Dreyer, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, A. Gillitzer, O. Golosov, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, V. Ivanov, A. Ivashkin, B. Kampfer, M. Kajetanowicz, KH. Kampert, B. Kardan, V. Khomyakov, I. Koenig, W. Koenig, G. Korcyl, G. Kornakov, F. Kornas, R. Kotte, A. Kozela, J. Kubos, A. Kugler, T. Kunz, P. Kurilkin, V. Kushpil, V. Ladygin, R. Lalik, A. Lebedev, S. Linev, L. Lopes, M. Lorenz, G. Lykasov, T. Mahmoud, A. Malakhov, J. Markert, S. Maurus, et al.
abstract
The matter formed in central heavy-ion collisions at a few GeV per nucleon is commonly understood as resonance matter, a gas of nucleons and excited baryon states with a substantial contribution from mesonic, mostly pionic excitations. Yet, in the initial phase of the reaction the system is compressed to beyond nuclear ground state density and hence substantial modifications of the hadron properties are expected to occur. The spectral distribution of virtual photons measured in Au+Au collisions at 2.4 GeV center of mass energy indicates strong medium effects beyond pure superposition of individual NN collisions. We present multi-differential distributions of low-mass electron pairs. This radiation is remarkably well described assuming emission from a thermalized system. To gain deeper understanding of the microscopic origin of the radiation, we extracted the centrality dependent true (not blue-shifted) temperature, its azimuthal distribution, as well as mass-dependent effective slope parameter. Virtual photon spectra are confronted with available model calculations.
Sub-threshold strangeness production measured with HADES
G. Kornakov, J. Adamczewski-Musch, O. Arnold, B. Arnoldi-Meadows, A. Belounnas, A. Belyaev, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, L. Chlad, P. Chudoba, I. Ciepal, C. Deveaux, D. Dittert, J. Dreyer, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, A. Gillitzer, O. Golosov, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, V. Ivanov, A. Ivashkin, B. Kampfer, M. Kajetanowicz, KH. Kampert, B. Kardan, V. Khomyakov, I. Koenig, W. Koenig, G. Korcyl, F. Kornas, R. Kotte, A. Kozela, J. Kubos, A. Kugler, T. Kunz, P. Kurilkin, V. Kushpil, V. Ladygin, R. Lalik, A. Lebedev, S. Linev, L. Lopes, M. Lorenz, G. Lykasov, T. Mahmoud, A. Malakhov, J. Markert, S. Maurus, V. Metag, et al.
abstract
At energies below root S-NN approximate to 2.55 GeV, strange quarks cannot be produced in binary nucleon-nucleon collisions because of the higher production threshold of the lightest hadrons carrying strangeness. Hence, the investigation of sub-threshold strangeness production in heavy-ion collisions is one of the most promising probes, to access the properties of the created system, as the missing energy must be provided by the latter one. For the first time, a nearly complete set of strange particles has been reconstructed in the 40% most central Au+Au collisions at. root S-NN = 2.42 GeV. The data sample includes multi-differential representations of charged and neutral particles containing strangeness (K-+/-,K-s(0), phi, Lambda). To achieve a better understanding of strangeness production the properties of the short-lived resonances have to be investigated. The first steps in this direction are presented here, including the reconstruction of baryon resonances using a new iterative technique, comparison to microscopic transport model calculations and interpretation of the pion transverse momentum distribution.
Time-Like Baryon Transitions studies with HADES
B. Ramstein, J. Adamczewski-Musch, O. Arnold, B. Arnoldi-Meadows, A. Belounnas, A. Belyaev, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, L. Chlad, P. Chudoba, I. Ciepal, C. Deveaux, D. Dittert, J. Dreyer, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, A. Gillitzer, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, M. Himmelreich, C. Hohne, R. Holzmann, A. Ierusalimov, V. Ivanov, A. Ivashkin, B. Kampfer, M. Kajetanowicz, KH. Kampert, T. Karavicheva, B. Kardan, V. Khomyakov, I. Koenig, W. Koenig, G. Korcyl, G. Kornakov, F. Kornas, R. Kotte, A. Kozela, J. Kubos, A. Kugler, T. Kunz, A. Kurepin, P. Kurilkin, V. Kushpil, V. Ladygin, R. Lalik, A. Lebedev, S. Linev, M. Liu, L. Lopes, M. Lorenz, G. Lykasov, et al.
abstract
The HADES collaboration uses the e(+)e(-) production as a probe of the resonance matter produced in collisions at incident energies of 1-3.5 GeV/nucleon at GSI. Elementary reactions provide useful references for these studies and give information on resonance Dalitz decays (R -> Ne(+)e(-)). Such processes are sensitive to the structure of time-like electromagnetic baryon transitions in a kinematic range where (off-shell) vector mesons play a crucial role. Results obtained in proton-proton reactions and in a commissioning pion-beam experiment are reported and prospects for future pion beam experiments and for first hyperon Dalitz decay measurements are described. The connection with the investigations of medium effects to be continued with HADES in the next years at SIS18 and SIS100 is also discussed.
Feasibility studies of the polarization of photons beyond the optical wavelength regime with the J-PET detector
P. Moskal, N. Krawczyk, B. C. Hiesmayr, M. Bała, C. Curceanu, E. Czerwinski, K. Dulski, A. Gajos, M. Gorgol, R. Del Grande, B. Jasinska, K. Kacprzak, L. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczynski, J. Raj, Z. Rudy, S. Sharma, M. Silarski, Shivani, R. Y. Shopa, M. Skurzok, W. Wislicki, B. Zgardzinska
abstract
J-PET is a detector optimized for registration of photons from the electron-positron annihilation via plastic scintillators where photons interact predominantly via Compton scattering. Registration of both primary and scattered photons enables to determinate the linear polarization of the primary photon on the event by event basis with a certain probability. Here we present quantitative results on the feasibility of such polarization measurements of photons from the decay of positronium with the J-PET and explore the physical limitations for the resolution of the polarization determination of 511keV photons via Compton scattering. For scattering angles of about 82 degree (where the best contrast for polarization measurement is theoretically predicted) we find
that the single event resolution for the determination of the polarization is about 40 degree (predominantly due to properties
of the Compton effect). However, for samples larger than ten thousand events the J-PET is capable of determining relative average polarization of these photons with the precision of about few degrees. The obtained results open new perspectives for studies of various physics phenomena such as quantum entanglement and tests of discrete symmetries in decays of positronium and extend the energy range of polarization measurements by five orders of magnitude beyond the optical wavelength regime.
Evaluation of Single-Chip, Real-Time Tomographic Data Processing on FPGA - SoC Devices
G. Korcyl, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, B. Flak, A. Gajos, B. Głowacz, M. Gorgol, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, M. Kajetanowicz, D. Kisielewska, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik- Niedźwiecka, M. Pałka, L. Raczyński, P. Rajda, Z. Rudy, P. Salabura, N. G. Sharma, S. Sharma, R. Y. Shopa, M. Skurzok, M. Silarski, P. Strzempek, A. Wieczorek, W. Wiślicki, R. Zaleski, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel approach to tomographic data processing
has been developed and evaluated using the Jagiellonian PET (J-
PET) scanner as an example. We propose a system in which there
is no need for powerful, local to the scanner processing facility,
capable to reconstruct images on the fly. Instead we introduce a
Field Programmable Gate Array (FPGA) System-on-Chip (SoC)
platform connected directly to data streams coming from the
scanner, which can perform event building, filtering, coincidence
search and Region-Of-Response (ROR) reconstruction by the
programmable logic and visualization by the integrated
processors. The platform significantly reduces data volume
converting raw data to a list-mode representation, while
generating visualization on the fly.
A feasibility study of the time reversal violation test based on polarization of annihilation photons from the decay of ortho-Positronium with the J-PET detector
J. Raj, A. Gajos, C. Curceanu, E. Czerwiński, K. Dulski, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a novel device being developed at Jagiellonian University in Krakow, Poland based on organic scintillators. J-PET is an axially symmetric and high acceptance scanner that can be used as a multi-purpose detector system. It is well suited to pursue tests of discrete symmetries in decays of positronium in addition to medical
imaging. J-PET enables the measurement of both momenta and the polarization vectors of annihilation photons. The latter is a unique feature of the J-PET detector which allows the study of time reversal symmetry violation operator which can be constructed solely from the annihilation photons momenta before and after the scattering in the detector.
Commissioning of the J-PET detector in view of the positron annihilation lifetime spectroscopy
K. Dulski, C. Curceanu, E. Czerwiński, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET device built from plastic scintillators. It is a multi-purpose detector designed for medical imaging and for studies of properties of positronium atoms in porous matter and in living organisms. In this article we report on the commissioning of the J-PET detector in view of studies of positronium decays. We present results of analysis of the positron lifetime measured in the porous polymer. The obtained results prove that J-PET is capable of performing simultaneous imaging of the density distribution of annihilation points as well as positron annihilation lifetime spectroscopy.
Feasibility study of the time reversal symmetry tests in decay of metastable positronium atoms with the J-PET detector
A. Gajos, C. Curceanu, E. Czerwinski, K. Dulski, M. Gorgol, N. Gupta-Sharma, B.C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohammed, Sz Niedzwiecki, M. Paalka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, Z. Rudy, S. Sharma, Shivani, R. Shopa, M. Silarski, M. Skurzok, W. Wislicki, B. Zgardzinska, M. Zielinski, P. Moskal
abstract
This article reports on the feasibility of testing of the symmetry under reversal in time in a purely leptonic system constituted by positronium atoms using the J-PET detector. The present state of T symmetry tests is discussed with an emphasis on the scarcely explored sector of leptonic systems. Two possible strategies of searching for manifestations of T violation in non-vanishing angular correlations of final state observables in the decays of metastable triplet states of positronium available with J-PET are proposed and discussed. Results of a pilot measurement with J-PET and assessment of its performance in reconstruction of three-photon decays are shown along with an analysis of its impact on the sensitivity of the detector for the determination of T -violation sensitive observables.
Estimating the NEMA characteristics of the J-PET tomograph using the GATE package
P. Kowalski, W. Wiślicki, R.Y. Shopa, L. Raczyński, K. Klimaszewski, C. Curcenau, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. Hiesmayr, B. Jasińska, Ł. Kapłon, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, S. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, S. Shivani, M. Silarski, M. Skurzok, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel whole-body positron emission tomography (PET) system based on plastic scintillators is
developed by the J-PET Collaboration. It consists of plastic scintillator strips arranged axially in the
form of a cylinder, allowing the cost-effective construction of the total-body PET system. In order to
determine the properties of the scanner prototype and optimize its geometry, advanced computer
simulations were performed using the GATE (Geant4 application for tomographic emission)
software.
The spatial resolution, sensitivity, scatter fraction and noise equivalent count rate were estimated
according to the National Electrical Manufacturers Association norm, as a function of the length
of the tomograph, the number of detection layers, the diameter of the tomographic chamber and
for various types of applied readout. For the single-layer geometry with a diameter of 85 cm, a strip
length of 100 cm, a cross-section of 4 mm × 20 mm and silicon photomultipliers with an additional
layer of wavelength shifter as the readout, the spatial resolution (full width at half maximum) in
the centre of the scanner is equal to 3 mm (radial, tangential) and 6 mm (axial). For the analogous
double-layer geometry with the same readout, diameter and scintillator length, with a strip crosssection
of 7 mm × 20 mm, a noise equivalent count rate peak of 300 kcps was reached at 40 kBq cc?1
activity concentration, the scatter fraction is estimated to be about 35% and the sensitivity at the
centre amounts to 14.9 cps kBq?1. Sensitivity profiles were also determined.
Sigma(0) production in proton nucleus collisions near threshold
J. Adamczewski-Musch, G. Agakishiev, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, S. Maurus, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, et al.
abstract
The production of Sigma(0) baryons in the nuclear reaction p (3.5 GeV) + Nb (corresponding to root sNN = 3.18 GeV) is studied with the detector set-up HADES at GSI, Darmstadt. Sigma(0)s were identified via the decay Sigma 0 -> Lambda gamma with subsequent decays Lambda -> p pi(-) in coincidence with a e(+)e(-) pair from either external (gamma -> e(+)e(-)) or internal (Dalitz decay gamma* -> e(+)e(-)) gamma conversions. The differential Sigma(0) cross section integrated over the detector acceptance, i.e. the rapidity interval 0.5 < y < 1.1, has been extracted as Delta sigma(Sigma 0) = 2.3 +/- (0.2)(stat) +/- ((+0.6)(-0.6))(sys) +/- (0.2)(norm) mB, yielding the inclusive production cross section in full phase space sigma(total)(Sigma 0) = 5.8 +/- (0.5)(stat) +/- ((+1.4)(-1.4))(sys) +/- (0.6)(norm) +/- (1.7)(extrapol) mb by averaging over different extrapolation methods. The Lambda(all)/Sigma(0) ratio within the HADES acceptance is equal to 2.3 +/- (0.2)(stat) +/- ((+0.6)(-0.6))(sys). The obtained rapidity and momentum distributions are compared to transport model calculations. The Sigma(0) yield agrees with the statistical model of particle production in nuclear reactions. (C) 2018 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license.
Pressure stabilized straw tube modules for the PANDA Forward Tracker
J. Smyrski, T. Fiutowski, P. Gianotti, A. Heczko, M. Idzik, M. Kajetanowicz, G. Korcyl, B. Korzeniak, R. Lalik, E. Lisowski, A. Malarz, W. Migdal, A. Misiak, W. Przygoda, J. Ritman, P. Salabura, M. Savrie, K. Swientek, P. Wintz, A. Wronska
abstract
The design of straw tube detector modules developed for the PANDA Forward Tracker is presented. One module consists of 32 straws with 10 mm diameter, arranged in two staggered layers, and has a very low material budget of only 8.8.10(-4 )X(0). The overpressure of the working gas mixture of 1 bar makes the module self-supporting and enables the use of lightweight and compact support frames. Detection planes in the Forward Tracker consist of modules mounted closely, without gaps, next to each other on a support frame. A module can be mounted and dismounted from the frame without the need to remove the neighboring modules, enabling fast repairs. Technical details of the detector design and the assembly procedure of the straw tubes and the straw modules as well as results of performed tests of the modules are given.
Centrality determination of Au plus Au collisions at 1.23A GeV with HADES
J. Adamczewski-Musch, O. Arnold, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, et al.
abstract
The centrality determination for Au + Au collisions at 1.23 A GeV, as measured with HADES at the GSI-SIS18, is described. In order to extract collision geometry related quantities, such as the average impact parameter or number of participating nucleons, a Glauber Monte Carlo approach is employed. For the application of this model to collisions at this relatively low centre-of-mass energy of root sNN = 2.42 GeV special investigations were performed. As a result a well defined procedure to determine centrality classes for ongoing analyses of heavy-ion data is established.
Deep sub-threshold phi production in Au plus Au collisions
J. Adamczewski-Musch, O. Arnold, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, R. Greifenhagen, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, et al.
abstract
We present data on charged kaons (K-+/-) and phi mesons in Au(1.23AGeV)+ Au collisions. It is the first simultaneous measurement of K- and phi mesons in central heavy-ion collisions below a kinetic beam energy of 10AGeV. The phi/K- multiplicity ratio is found to be surprisingly high with a value of 0.52 +/- 0.16and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K- transverse-mass spectra can be explained solely by feed-down, which substantially softens the spectra of K- mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze-out temperatures of K+ and K- mesons caused by different couplings to baryons. (C) 2018 The Author(s). Published by Elsevier B.V.
Readout Electronics and Data Acquisition for Gaseous Tracking Detectors
G. Korcyl, P. Strzempek, A. Apostolou, T. Fiutowski, M. Idzik, M. Kajetanowicz, D. Przyborowski, P. Salabura, J. Smyrski, K. Swientek, P. Wintz
abstract
A complete, general solution for collecting and processing data from gaseous tracking detectors in high-rate applications has been developed. The readout chain consists of front-end modules equipped with PASTTREC ASIC chips and trigger readout boards version 3 (TRBv3) as a readout platform. The platform is accompanied by dedicated control, monitoring, and data quality assessment software. The entire system has been evaluated with a tracking system based on straw detectors in laboratory and in-beam experiments. In this paper, we present key elements of the system as well as results of various tests. The measured PASTTREC operation characteristics and the TRBv3 specification used for the readout allow us to adapt and to integrate it to the existing HADES spectrometer and the PANDA detector, an experiment under construction, both located at the FAIR facility in Darmstadt.
A Method to Produce Linearly Polarized Positrons and Positronium Atoms with the J-PET Detector
M. Mohammed, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, J. Raj, Z. Rudy, N.G. Sharma, S. Sharma, Shivani, M. Skurzok, M. Silarski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A method for creating linearly polarized positrons and ortho-positronium (o-Ps) atoms with the J-PET detector is presented. The unique geometry and properties of the J-PET tomography enable one to design a positron source such that the quantization axis for the estimation of the linear polarization of produced o-Ps can be determined on the event by event basis in a direction of the positron motion. We intend to use 22Na or other beta+ decay isotopes as a source of polarized positrons. Due to the parity violation in the beta decay, the emitted positrons are longitudinally polarized. The choice of the quantization axis is based on the known position of the positron emitter and the reconstructed position of the positronium annihilation. We show that the J-PET tomography is equipped with all needed components.
Human Tissue Investigations Using PALS Technique - Free Radicals Influence
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Pietrow, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B.C. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
The positron annihilation lifetime spectroscopy was applied to the samples of the human uterine leiomyomas and the normal myometrium tissues taken from the selected place of the uterus during a surgery. The method indicated differences in values of the measured positron annihilation lifetime spectroscopy parameters (lifetimes and intensities) between healthy and diseased tissue samples. The additional measurements were performed either in darkness or in presence of visible light which influenced the free radicals present in both kind of tissues and, as a result, made changes in free annihilation and o-Ps decay lifetime and intensity values.
Preliminary Studies of J-PET Detector Spatial Resolution
M. Pawlik-Niedźwiecka, S. Niedźwiecki, D. Alfs, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pałka, L. Raczyński, J. Raj, Z. Rudy, Shivani, M. Silarski, M. Skurzok, N.G. Sharma, S. Sharma, R.Y. Shopa, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The J-PET detector, based on long plastic scintillator strips, was recently constructed at the Jagiellonian University. It consists of 192 modules axially arranged into three layers, read out from both sides by digital constant-threshold front-end electronics. This work presents preliminary results of measurements of the spatial resolution of the J-PET tomograph performed with 22Na source placed at selected position inside the detector chamber.
Analysis procedure of the positronium lifetime spectra for the J-PET detector
K. Dulski , B. Zgardzińska , P. Białas , C. Curceanu E. Czerwiński , A. Gajos , B. Głowacz , M. Gorgol , B. C. Hiesmayr , B. Jasińska , D. Kisielewska-Kamińska , G. Korcyl , P. Kowalski , T. Kozik , N. Krawczyk , W. Krzemień , E. Kubicz , M. Mohammed , M. Pawlik-Niedźwiecka, S. Niedźwiecki , M. Pałka , L. Raczyński , J. Raj , Z. Rudy , N. G. Sharma, S. Sharma, Shivani, R. Y. Shopa, M. Silarski , M. Skurzok , A. Wieczorek , W. Wiślicki , M. Zieliński , P. Moskal
abstract
Positron Annihilation Lifetime Spectroscopy (PALS) has shown to be a powerful tool to study the nanostructures of porous materials. Positron Emissions Tomography (PET) are devices allowing imaging of metabolic processes e.g. in human bodies. A newly developed device, the J-PET (Jagiellonian PET), will allow PALS in addition to imaging, thus combining both analyses providing new methods for physics and medicine. In this contribution we present a computer program that is compatible with the J-PET software. We compare its performance with the standard program LT 9.0 by using PALS data from hexane measurements at different temperatures. Our program is based on an iterative procedure, and our fits prove that it performs as good as LT 9.0.
Introduction of total variation regularization into filtered backprojection algorithm
L. Raczyński, W. Wiślicki, K. Klimaszewski, W. Krzemień, P. Kowalski, R. Shopa, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, N.G. Sharma, S. Sharma, M. Silarski, M. Skurzok, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
In this paper we extend the state-of-the-art filtered backprojection (FBP) method with application of the concept of Total Variation regularization. We compare the performance of the new algorithm with the most common form of regularizing in the FBP image reconstruction via apodizing functions. The methods are validated in terms of cross-correlation coefficient between reconstructed and real image of radioactive tracer distribution using standard Derenzo-type phantom. We demonstrate that the proposed approach results in higher cross-correlation values with respect
to the standard FBP method.
Time calibration of the J-PET detector
M. Skurzok, M. Silarski, D. Alfs, P. Bialas, Shivani, C. Curceanu , E. Czerwinski , K. Dulski , A. Gajos, B. G lowacz , M. Gorgol, B. C. Hiesmayr, B. Jasinska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik , N. Krawczyk, W. Krzemien, E. Kubicz , M. Mohammed, M. Pawlik-Niedzwiecka, S. Niedzwiecki, M. Palka, L. Raczynski , J. Raj, Z. Rudy, N. G. Sharma, S. Sharma , R. Y. Shopa , A. Wieczorek, W. Wislicki , B. Zgardzinska, M. Zielinski, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) project carried out in the Institute of Physics of the Jagiellonian University is focused on construction and tests of the first prototype of PET scanner for medical diagnostic which allows for the simultaneous 3D imaging of the whole human body using organic scintillators. The J-PET prototype consists of 192 scintillator strips forming three cylindrical layers which are optimized for the detection of photons from the electron-positron annihilation with high time- and high angular-resolutions. In this article we present time calibration and synchronization of the whole J-PET detection system by irradiating each single detection module with a 22Na source and a small detector providing common reference time for synchronization of all the modules.
Novel scintillating material 2-(4-styrylphenyl)benzoxazole for the fully digital and MRI compatible J-PET tomograph based on plastic scintillators
A. Wieczorek, K. Dulski, Sz. Niedźwiecki, D. Alfs, P. Białas, C. Curceanu, E. Czerwiński, A. Danel, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, K. Kacprzak, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Kucharek, M. Mohammed, M. Pawlik-Niedźwiecka, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N. G. Sharma, M. Silarski, T. Uchacz, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel
plastic
scintillator
is developed
for
the
application
in the
digital
positron
emission
tomography
(PET).
The
novelty
of the
concept
lies
in application
of the
2-(4-styrylphenyl)
benzoxazole
as
a wavelength
shifter.
The
substance
has
not
been
used
as
scintillator
dop-
ant
before.
A dopant
shifts
the
scintillation
spectrum
towards
longer
wavelengths
making
it
more
suitable
for
applications
in scintillators
of long
strips
geometry
and
light
detection
with
digital
silicon
photomultipliers.
These
features
open
perspectives
for
the
construction
of the
cost-effective
and
MRI-compatib
le PET
scanner
with
the
large
field
of view.
In this
article
we
present
the
synthesis
method
and
characterize
performance
of the
elaborated
scintillator
by
determining
its
light
emission
spectrum,
light
emission
efficiency,
rising
and
decay
time
of
the
scintillation
pulses
and
resulting
timing
resolution
when
applied
in the
positron
emission
tomography.
The
optimal
concentratio
n of the
novel
wavelength
shifter
was
established
by
maximizing
the
light
output
and
it was
found
to be
0.05
?
for
cuboidal
scintillator
with
dimen-
sions
of 14
mm
x 14
mm
x 20
mm.
Commissioning of the J-PET Detector for Studies of Decays of Positronium Atoms
E. Czerwiński, K. Dulski, P. Białas, C. Curceanu, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R.Y. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging of the whole human body as well as for physics studies involving detection of electron?positron annihilation into photons. J-PET has high angular and time resolution, and allows for measurement of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for the background rejection in the decays of positronium atoms.
J-PET: A New Technology for the Whole-body PET Imaging
S. Niedźwiecki, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, Ł. Kapłon, D. Kisielewska-Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R.Y. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.
Three-dimensional Image Reconstruction in J-PET Using Filtered Back-projection Method
R.Y. Shopa, K. Klimaszewski, P. Kowalski, W. Krzemień, L. Raczyński, W. Wiślicki, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, N.G. Sharma, S. Sharma, M. Silarski, M. Skurzok, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
We present a method and preliminary results of the image reconstruction in the Jagiellonian PET tomograph. Using GATE (Geant4 Application for Tomographic Emission), interactions of the 511 keV photons with a cylindrical detector were generated. Pairs of such photons, flying back-to-back, originate from e+e? annihilations inside a 1 mm spherical source. Spatial and temporal coordinates of hits were smeared using experimental resolutions of the detector. We incorporated the algorithm of the 3D Filtered Back Projection, implemented in the STIR and TomoPy software packages, which differ in approximation methods. Consistent results for the Point Spread Functions of ? 5 ÷ 7 mm and ? 9 ÷ 20 mm were obtained, using STIR, for transverse and longitudinal directions, respectively, with no time-of-flight information included.
Human Tissues Investigation Using PALS Technique
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Samples of uterine leiomyomatis and normal tissues taken from patients after surgery were investigated using the Positron Annihilation Lifetime Spectroscopy (PALS). Significant differences in all PALS parameters between normal and diseased tissues were observed. For all studied patients, it was found that the values of the free annihilation and ortho-positronium lifetime are larger for the tumorous tissues than for the healthy ones. For most of the patients, the intensity of the free annihilation and ortho-positronium annihilation was smaller for the tumorous than for the healthy tissues. For the first time, in this kind of studies, the 3? fraction of positron annihilation was determined to describe changes in the tissue porosity during morphologic alteration.
A facility for pion-induced nuclear reaction studies with HADES
J. Adamczewski-Musch, O. Arnold, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, S. Morozov, C. Muntz, R. Munzer, et al.
abstract
The combination of a production target for secondary beams, an optimized ion optical beam line setting, in-beam detectors for minimum ionizing particles with high rate capability, and an efficient large acceptance spectrometer around the reaction target constitutes an experimental opportunity to study in detail hadronic interactions utilizing pion beams impinging on nucleons and nuclei. For the 0.4-2.0 GeV/c pion momentum regime such a facility is located at the heavy ion synchrotron accelerator SIS18 in Darm-stadt (Germany). The layout of the apparatus, performance of its components and encouraging results from a first commissioning run are presented.
Human Tissues Investigation Using PALS Technique
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B.C. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Samples of uterine leiomyomatis and normal tissues taken from patients
after surgery were investigated using the Positron Annihilation Lifetime
Spectroscopy (PALS). Significant differences in all PALS parameters
between normal and diseased tissues were observed. For all studied patients,
it was found that the values of the free annihilation and orthopositronium
lifetime are larger for the tumorous tissues than for the healthy
ones. For most of the patients, the intensity of the free annihilation and
ortho-positronium annihilation was smaller for the tumorous than for the
healthy tissues. For the first time, in this kind of studies, the 3gamma fraction
of positron annihilation was determined to describe changes in the tissue
porosity during morphologic alteration.
Multichannel FPGA based MVT system for high precision time (20 ps RMS) and charge measurement
M. Palka, P. Strzempek, G. Korcyl, T. Bednarski, S. Niedzwiecki, P. Bialas, E. Czerwinski, K. Dulski, A. Gajos, B. Glowacz, M. Gorgol, B. Jasinska, D. Kaminska, M. Kajetanowicz, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohhamed, L. Raczynski, Z. Rudy, O. Rundel, P. Salabura, NG. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wislicki, M. Zielinski, B. Zgardzinska, P. Moskal
abstract
In this article it is presented an FPGA based Multi-Voltage Threshold (MVT) system which allows of sampling fast signals (1-2 ns rising and falling edge) in both voltage and time domain. It is possible to achieve a precision of time measurement of 20 ps RMS and reconstruct charge of signals, using a simple approach, with deviation from real value smaller than 10%. Utilization of the differential inputs of an FPGA chip as comparators together with an implementation of a TDC inside an FPGA allowed us to achieve a compact multi-channel system characterized by low power consumption and low production costs. This paper describes realization and functioning of the system comprising 192-channel TDC board and a four mezzanine cards which split incoming signals and discriminate them. The boards have been used to validate a newly developed Time-of-Flight Positron Emission Tomography system based on plastic scintillators. The achieved full system time resolution of sigma (TOF) approximate to 68 ps is by factor of two better with respect to the current TOF-PET systems.
Analysis of the exclusive final state npe(+)e(-) in the quasi-free np reaction
J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hoehne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, W. Kuehn, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, T. Liu, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, DM. Mihaylov, et al.
abstract
We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u impinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of e(+)e(-) pairs above the pi(0) mass in the exclusive channel dp -> npe(+)e(-)(p(spect)) as compared to the exclusive channel ppe(+)e(-) measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-Delta excitation combined with intermediate rho-meson production. Differential cross sections as a function of the e(+)e(-) invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical sides.
Delta (1232) Dalitz decay in proton-proton collisions at T=1.25 GeV measured with HADES at GSI
J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, A. Belounnas, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Boehmer, P. Bordalo, S. Chernenko, L. Chlad, C. Deveaux, J. Dreyer, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Filip, P. Finocchiaro, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Heinz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, T. Liu, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, S. Maurus, V. Metag, J. Michel, et al.
abstract
We report on the investigation of Delta(1232) production and decay in proton-proton collisions at a kinetic energy of 1.25 GeV measured with HADES. Exclusive dilepton decay channels ppe(+) e(-) and ppe(+) e(-). have been studied and compared with the partial-wave analysis of the hadronic pp pi(0) channel. They allow to access both Delta(+) -> p pi(0)( e(+) e(-) gamma) and Delta(+) -> pe(+) e(-) Dalitz decay channels. The perfect reconstruction of the well-known pi(0) Dalitz decay serves as a proof of the consistency of the analysis. The Delta Dalitz decay is identified for the first time and the sensitivity to N-Delta transition form factors is tested. The Delta (1232) Dalitz decay branching ratio is also determined for the first time; our result is (4.19 +/- 0.62 syst. +/- 0.34 stat.) x 10(-5), albeit with some model dependence.
Design of the forward straw tube tracker for the PANDA experiment
J. Smyrski, A. Apostolou, J. Biernat, W. Czyzycki, G. Filo, E. Fioravanti, T. Fiutowski, P. Gianotti, M. Idzik, G. Korcyl, K. Korcyl, E. Lisowski, F. Lisowski, J. Plazek, D. Przyborowski, W. Przygoda, J. Ritman, P. Salabura, M. Savrie, P. Strzempek, K. Swientek, P. Wintz, A. Wronska
abstract
The design of the Forward Tracker for the Forward Spectrometer of the PANDA experiment is described. The tracker consists of 6 tracking stations, each comprising 4 planar double layers of straw tube detectors, and has a total material budget of only 2% X-0. The straws are made self-supporting by a 1 bar over-pressure of the working gas mixture (Ar/CO2). This allows to use lightweight and compact rectangular support frames for the double layers and to split the frames into pairs of C-shaped half-frames for an easier installation on the beam line.
Calculation of the time resolution of the J-PET tomograph using kernel density estimation
L. Raczyński, W. Wiślicki, W. Krzemień, P. Kowalski, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzińska, M. Zieliński and P. Moskal
abstract
In this paper we estimate the time resolution of the J-PET scanner built from plastic scintillators. We incorporate the method of signal processing using the Tikhonov regularization framework and the kernel density estimation method. We obtain simple, closed-form analytical formulae for time resolution. The proposed method is validated using signals registered by means of the single detection unit of the J-PET tomograph built from a 30?cm long plastic scintillator strip. It is shown that the experimental and theoretical results obtained for the J-PET scanner equipped with vacuum tube photomultipliers are consistent.
Measurement of gamma quantum interaction point in plastic scintillator with WLS strips
J. Smyrski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. Jasińska, M. Kajetanowicz, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, P. Salabura, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, J. Wojnarska, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The feasibility of measuring the aśxial coordinate of a gamma quantum interaction point in a plastic scintillator
bar via the detection of scintillation photons escaping from the scintillator with an array of wavelength-shifting
(WLS) strips is demonstrated. Using a test set-up comprising a BC-420 scintillator bar and an array of sixteen
BC-482A WLS strips we achieved a spatial resolution of 5 mm (?) for annihilation photons from a 22Na isotope.
The studied method can be used to improve the spatial resolution of a plastic-scintillator-based PET scanner
which is being developed by the J-PET collaboration.
J-PET: A Novel TOF -PET scanner using Organic Scintillators
N.G. Sharma, M. Silarski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, A. Wieczorek, W. Wislicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
Positron Emission Tomography (PET) is one of the most advanced nuclear medicine imaging techniques that
have potential to identify many diseases (like cancers, heart diseases, neurological disorders and other abnormalities) in vivo in the earliest stages. However, production of PET modalities for covering the whole human body is economically unrealistic when applying the current technologies. In order to achieve a goal of more economical PET scanner with large geometrical acceptance and improved time resolution, the Jagiellonian Positron Emission Tomography (J-PET) Collaboration is realizing a new project aiming at construction of TOF-PET detector using plastic scintillators instead of crystals. Novelty of the J-PET scanner lies in: (i) application of plastic scintillators as well as in (ii) its front-end electronics which allows signal sampling in voltage domain, (iii) a trigger-less data acquisition system, and (iv) the new time and hit-position reconstruction methods. Moreover, the proposed solution enables to increase the axial field-of-view of the tomograph by extending the length of the plastic scintillator strips without changing the number of photomultipliers and electronic channels.
Lambda p interaction studied via femtoscopy in p plus Nb reactions at root s(NN)=3.18 GeV
J. Adamczewski-Musch, G. Agakishiev, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, S. Maurus, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, et al.
abstract
We report on the first measurement of p Lambda and pp correlations via the femtoscopy method in p + Nb reactions at root sNN = 3.18 GeV, studied with the High Acceptance Di-Electron Spectrometer (HADES). By comparing the experimental correlation function to model calculations, a source size for pp pairs of r(0,pp) = 2.02 +/- 0.01(stat)(-0.12)(+0.11)(sys) fm and a slightly smaller value for p Lambda pairs of r(0,Lambda p) = 1.62 +/- 0.02(stat)(-0.08)(+0.19)(sys) fm are extracted. Using the geometrical extent of the particle-emitting region, determined experimentally with pp correlations as reference together with a source function from a transport model, it is possible to study different sets of scattering parameters. The p Lambda correlation is proven to be sensitive to predicted scattering length values from chiral effective field theory. We demonstrate that the femtoscopy technique can be used as a valid alternative to the analysis of scattering data to study the hyperon-nucleon interaction.
A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators
D. Kamińska, A. Gajos, E. Czerwiński, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, K. Dulski, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
We present a study of the application of the Jagiellonian Positron Emission Tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition
to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps->3g decays with angular and energy resolution equal to sigma(theta) = 0.4^{circ} and sigma(E) = 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pileups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.
Development of a dedicated front-end electronics for straw tube trackers in the (P)over-barANDA experiment
D. Przyborowski, T. Fiutowski, M. Idzik, M. Kajetanowicz, G. Korcyl, P. Salabura, J. Smyrski, P. Strzempek, K. Swientek, P. Terlecki, J. Tokarz
abstract
The design and tests of front-end electronics for straw tube trackers in the PANDA experiment at FAIR are presented. The challenges for the front-end electronics, comprising operation at high counting rate up to 1MHz per straw tube, are discussed and the proposed architecture comprising a switched gain charge sensitive preamplifier (CSP), a pole-zero cancellation circuit (PZC), a second order variable peaking time shaper, a trimming ion tail cancellation circuit, and a baseline holder (BLH), is described. The front-end provides an analogue output and a discriminator with LVDS differential driver for the Time-of-Arrival (ToA) and Time-over-Threshold (ToT) measurements. A prototype readout ASIC featuring four channels was fabricated in 0.35 mu m CMOS technology consuming 15.5 mW (analog part) and 12 mW (LVDS) per channel. The results of measurements of peaking time (25-67 ns), gain, noise (ENC 800-2500 el. for various gains), time walk and jitter are presented as well as the first results obtained with prototype straw tubes connected.
Determination of the 3gamma Fraction from Positron Annihilation in Mesoporous Materials for Symmetry Violation Experiment with J-PET Scanner
B. Jasińska, M. Gorgol, M. Wiertel, R. Zaleski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos B. Głowacz, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
Various mesoporous materials were investigated to choose the best material for experiments requiring high yield of long-lived positronium. We found that the fraction of 3? annihilation determined using ?-ray energy spectra and positron annihilation lifetime spectra (PAL) changed from 20% to 25%. The 3? fraction and o-Ps formation probability in the polymer XAD-4 is found to be the largest. Elemental analysis performed using scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscope EDS shows high purity of the investigated materials.
Sampling FEE and Trigger-less DAQ for the J-PET Scanner
G. Korcyl, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B. Jasińska, D. Kamińska Ł. Kapłon, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, K. Stoła, A. Strzelecki, A. Wieczorek, W. Wiślicki, B.K. Zgardzińska, M. Zieliński, P. Moskal
abstract
In this paper, we present a complete Data Acquisition System (DAQ) together with the readout mechanisms for the J-PET tomography scanner. In general, detector readout chain is constructed out of Front-End Electronics (FEE) measurement devices such as Time-to-Digital or Analog-to-Digital Converters (TDCs or ADCs), data collectors and storage. We have developed a system capable for maintaining continuous readout of digitized data without preliminary selection. Such operation mode results in up to 8 Gbps data stream, therefore, it is required to introduce a dedicated module for on-line event building and feature extraction. The Central Controller Module, equipped with Xilinx Zynq SoC and 16 optical transceivers, serves as such true real time computing facility. Our solution for the continuous data recording (trigger-less) is a novel approach in such detector systems and assures that most of the information is preserved on the storage for further, high-level processing. Signal discrimination applies a unique method of using LVDS buffers located in the FPGA fabric.
Beam Profile Investigation of the New Collimator System for the J-PET Detector
E. Kubicz, M. Silarski, A. Wieczorek, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, B. Jasińska D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, M. Mohammed, I. Moskal, S. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, A. Strzelecki, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose detector which will be used for search for discrete symmetries violations in the decays of positronium atoms and for investigations with positronium atoms in life-sciences and medical diagnostics. In this article, we present three methods for determination of the beam profile of collimated annihilation gamma quanta. Precise monitoring of this profile is essential for time and energy calibration of the J-PET detector and for the determination of the library of model signals used in the hit-time and hit-position reconstruction. We have shown that usage of two lead bricks with dimensions of 5 × 10 × 20 cm3 enables to form a beam of annihilation quanta with Gaussian profile characterized by 1 mm FWHM. Determination of this characteristic is essential for designing and construction the collimator system for the 24-module J-PET prototype. Simulations of the beam profile for different collimator dimensions were performed. This allowed us to choose optimal collimation system in terms of the beam profile parameters, dimensions and weight of the collimator taking into account the design of the 24-module J-PET detector.
Scatter Fraction of the J-PET Tomography Scanner
P. Kowalski, W. Wiślicki, L. Raczyński, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, J. Jasińska D. Kamińska, G. Korcyl, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammad, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, M. Silarski, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET Collaboration. In this article, we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.
Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, N. Gupta-Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
Trilateration-based reconstruction of ortho-positronium decays into three photons with the J-PET detector
A. Gajos, D. Kamińska, E. Czerwiński, D. Alfs, T. Bednarski, P. Białas, B. Głowacz, M. Gorgol, B. Jasińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
This work reports on a new reconstruction algorithm allowing us to reconstruct the decays of ortho-positronium atoms into three photons using the places and times of photons recorded in the detector. The method is based on trilateration and allows for a simultaneous reconstruction of both location and time of the decay. Results of resolution tests of the new reconstruction in the J-PET detector based on Monte Carlo simulations are presented, which yield a spatial resolution at the level of 2 cm (FWHM) for X and Y and at the level of 1 cm (FWHM) for Z available with the present resolution of J-PET after application of a kinematic fit. Prospects of employment of this method for studying angular correlations of photons in decays of polarized ortho-positronia for the needs of tests of CP and CPT discrete symmetries are also discussed. The new reconstruction method allows for discrimination of background from random three-photon coincidences as well as for application of a novel method for determination of the linear polarization of ortho-positronium atoms, which is also introduced in this work.
Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph
P. Moskal, O. Rundel, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, K. Giergiel, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, A. Słomski, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Recent tests of a single module of the Jagiellonian Positron Emission
Tomography system (J-PET) consisting of 30 cm long plastic scintillator
strips have proven its applicability for the detection of annihilation quanta
(0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The
achieved resolution is almost by a factor of two better with respect to the
current TOF-PET detectors and it can still be improved since, as it is shown
in this article, the intrinsic limit of time resolution for the determination of
time of the interaction of 0.511 MeV gamma quanta in plastic scintillators
is much lower. As the major point of the article, a method allowing to
record timestamps of several photons, at two ends of the scintillator strip,
by means of matrix of silicon photomultipliers (SiPM) is introduced. As a
result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with
the growing number of photomultipliers, and that the 2×5 configuration at
two ends allowing to read twenty timestamps, constitutes an optimal solution.
The conducted simulations accounted for the emission time distribution,
photon transport and absorption inside the scintillator, as well as quantum
efficiency and transit time spread of photosensors, and were checked based on
the experimental results. Application of the 2×5 matrix of SiPM allows for
achieving the coincidence resolving time in positron emission tomography of
0.170 ns for 15 cm axial field-of-view (AFOV) and 0.365 ns for 100 cm
AFOV. The results open perspectives for construction of a cost-effective TOFPET
scanner with significantly better TOF resolution and larger AFOV with
respect to the current TOF-PET modalities.
Overview of the software architecture and data flow for the J-PET tomography device
W. Krzemień, D. Alfs, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, E. Kubicz, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Modern TOF-PET scanner systems require high-speed computing resources for efficient data processing, monitoring and image reconstruction. In this article we present the data flow and software architecture for the novel TOF-PET scanner developed by the J-PET collaboration. We discuss the data acquisition system, reconstruction framework and some image reconstruction issues. Also, the concept of computing outside hospitals in the remote centers such as 'Swierk Computing Centre in Poland is presented
Potential of the J-PET Detector for Studies of Discrete Symmetries in Decays of Positronium Atom - a Purely Leptonic System
P. Moskal, D. Alfs, T. Bednarski, P. Białas, E. Czerwinski, C. Curceanu, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasinska, D. Kaminska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien , N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Pawlik-Niedzwiecka, L. Raczynski, Z. Rudy, M. Silarski, A. Wieczorek, W. Wislicki, M. Zielinski
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) was constructed
as a prototype of the cost-effective scanner for the simultaneous
metabolic imaging of the whole human body. Being optimized for the detection
of photons from the electron?positron annihilation with high timeand
high angular-resolution, it constitutes a multi-purpose detector providing
new opportunities for studying the decays of positronium atoms.
Positronium is the lightest purely leptonic object decaying into photons.
As an atom bound by a central potential, it is a parity eigenstate, and
as an atom built out of an electron and an anti-electron, it is an eigenstate
of the charge conjugation operator. Therefore, the positronium is
a unique laboratory to study discrete symmetries whose precision is limited,
in principle, by the effects due to the weak interactions expected at the level of (10????14) and photon?photon interactions expected at the
level of (10????9). The J-PET detector enables to perform tests of discrete
symmetries in the leptonic sector via the determination of the expectation
values of the discrete-symmetries-odd operators, which may be constructed
from the spin of ortho-positronium atom and the momenta and polarization
vectors of photons originating from its annihilation. In this article, we
present the potential of the J-PET detector to test the C, CP, T and CPT
symmetries in the decays of positronium atoms.
Readout Electronics and Data Acquisition for Gaseous Tracking Detectors
M. Idzik, G. Korcyl, D. Przyborowski, P. Salabura, J. Smyrski, P. Strzempek
abstract
A complete solution for collecting and processing data from gaseous tracking detectors has been developed. The readout chain consists of Front-End Modules (FEM) equipped with PASTTREC2 ASIC chips and Trigger Readout Board v3 (TRBv3) as a readout platform, together with control and monitoring mechanisms and data quality assessment software. The entire system has been evaluated in the laboratory as well as in-beam experiments. The results show drift time measurement and Time-over-Threshold time precision measurement below 1 ns and a high counting rate performance per channel. Measured PASTTREC2 operation characteristics as well as the TRBv3 platform used for readout allow to adapt and integrate the system under discussion to the existing HADES spectrometer and the PANDA detector, an experiment under construction, both located at FAIR facility in Darmstadt.
Strange hadron production at SIS energies: an update from HADES
M. Lorenz, J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, et al.
abstract
We present and discuss recent experimental activities of the HADES collaboration on open and hidden strangeness production close or below the elementary NN threshold. Special emphasis is put on the feed-down from phi mesons to antikaons, the presence of the Xi(-) excess in cold nuclear matter and the comparison of statistical model rates to elementary p+p data. The implications for the interpretation of heavy-ion data are discussed as well.
J-PET: A Novel TOF-PFT Detector based on Plastic Scintillators
P. Moskal, D. Alfs, T. Bednarski, P. Bialas, C. Curceanu, E. Czerwinski, K. Dulski, A. Gajos, B. Glowacz, M. Gorgol, B. Hiesmayr, B. Jasinska, D. Kaminska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohammed, M. Pawlik-Niedzwiecka, S. Niedzwiecki, M. Palka, L. Raczynski, Z. Rudy, O. Rundel, NG. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wislicki, B. Zgardzinska, M. Zielinski
abstract
The purpose of the reported research is the elaboration of the method for construction of the cost-effective whole body single-bed positron emission tomography scanner enabling simultaneous PET/CT and PET/MR imaging The Jagiellonian Positron Emission Tomograph (J-PET) is built out of 192 scintillator strips arranged axially in three layers forming a cylindrical diagnostic chamber with the diameter of 85 cm and axial field of-view of 50 cm. The novelty of the concept lies in employing long strips of plastic scintillators instead of crystals as detectors of the annihilation quanta, and in using the timing of signals instead of their amplitudes for the reconstruction of Lines-of Response. To take advantage of the superior timing properties of plastic scintillators a novel multi-voltage-threshold front-end electronics was developed allowing for sampling of signals in a voltage domain. An axial arrangement of long strips of plastic scintillators, and their small light attenuation allows us to make a TOE-PET scanner with a long axial field-of-view. The presented solution opens unique possibilities of combining PET with CT and PET with MRI for scanning the same part of a patient at the same time with both methods. The relative ease of the cost effective increase of the axial field-of-view makes the J-PET tomograph competitive with respect to the current commercial PET scanners as regards sensitivity and time resolution.
Statistical Analysis of Time Resolution of the J-PET Scanner
L. Raczynski, W. Wislicki, P. Kowalski, W. Krzemien, D. Alfs, T. Bednarski, P. Bialas, C. Curceanu, E. Czerwinski, K. Dulski, A. Gajos, B. Glowacz, M. Gorgol, B. Hiesmayr, B. Jasinska, D. Kaminska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedzwiecka, S. Niedzwiecki, M. Palka, Z. Rudy, O. Rundel, NG. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzinska, M. Zielinski, P. Moskal
abstract
The commercial Positron Emission Tomography (PET) scanners use inorganic crystal scintillators for the detection of gamma photons. The Jagiellonian-PET (J-PET) detector exhibits high time resolution due to use of fast plastic scintillators and dedicated electronics circuits. Since the time resolution of PET scanner is influenced by numerous factors, e.g. a type of photomultipliers attached to the scintillators, the optimal selection of components of the J-PET system requires detailed understanding of the method for calculation the time resolution. In this paper we show the idea of this method, based on statistical analysis of the observed signals on the photomultiplier's output. The method is tested using signals registered by means of the single detection module of the J-PET scanner built out from 30 cm long plastic scintillator strips. We investigate two main factors affecting the photon registration probability, photomultipliers quantum efficiency and photomultipliers transit time spread. We demonstrate that the quantum efficiency of photomultipliers represents the most important factor influencing overall performance of the J-PET scanner.
Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph
P. Moskal, D. Alfs, T. Bednarski, P. Bialas, C. Curceanu, E. Czerwinski, K. Dulski, A. Gajos, B. Glowacz, N. Gupta-Sharma, M. Gorgol, BC. Hiesmayr, B. Jasinska, D. Kaminska, O. Khreptak, G. Korcyl, P. Kowalski, W. Krzemien, N. Krawczyk, E. Kubicz, M. Mohammed, S. Niedzwiecki, M. Pawlik-Niedzwiecka, L. Raczynski, Z. Rudy, M. Silarski, J. Smyrski, A. Wieczorek, W. Wislicki, B. Zgardzinska, M. Zielinski
abstract
Discrete symmetries such as parity (P), charge-conjugation (C) and time reversal (T) are of fundamental importance in physics and cosmology. Breaking of charge conjugation symmetry (C) and its combination with parity (CP) constitute necessary conditions for the existence of the asymmetry between matter and antimatter in the observed Universe. The presently known sources of discrete symmetries violations can account for only a tiny fraction of the excess of matter over antimatter. So far CP and T symmetries violations were observed only for systems involving quarks and they were never reported for the purely leptonic objects. In this article we describe briefly an experimental proposal for the test of discrete symmetries in the decays of positronium atom which is made exclusively of leptons. The experiments are conducted by means of the Jagiellonian Positron Emission Tomograph (J-PET) which is constructed from strips of plastic scintillators enabling registration of photons from the positronium annihilation. J-PET tomograph together with the positronium target system enable to measure expectation values for the discrete symmetries odd operators constructed from (i)spin vector of the ortho-positronium atom, (ii) momentum vectors of photons originating from the decay of positronium, and (iii) linear polarization direction of annihilation photons. Linearly polarized positronium will be produced in the highly porous aerogel or polymer targets, exploiting longitudinally polarized positrons emitted by the sodium Na-22 isotope. Information about the polarization vector of ortho-positronium will be available on the event by event basis and will be reconstructed from the known position of the positron source and the reconstructed position of the ortho-positronium annihilation. In 2016 the first tests and calibration runs are planned, and the data collection with high statistics will commence in the year 2017.
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
D. Kamińska, A. Gajos, E. Czerwiński, T. Bednarski, P. Białas, M. Gorgol, B. Jasińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
In this paper, we present prospects for using the Jagiellonian positron emission tomograph (J-PET)
detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We
discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero
expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons
would imply the existence of physics phenomena beyond the standard model. Previous measurements resulted
in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of
about 10?3. The J-PET detector allows to determine those values with better precision, thanks to the unique
time and angular resolution combined with a high geometrical acceptance. Achieving the aforementioned is possible
because of the application of polymer scintillators instead of crystals as detectors of annihilation quanta.
Studies of unicellular microorganisms Saccharomyces cerevisiae by means of positron annihilation lifetime spectroscopy
E. Kubicz, B. Jasińska, B. Zgardzińska, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rajfur, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Results of positron annihilation lifetime spectroscopy (PALS) and microscopic studies on simple microorganisms,
brewing yeasts, are presented. Lifetime of ortho-positronium (o-Ps) were found to change from 2.4 to 2.9 ns
(longer-lived component) for lyophilized and aqueous yeasts, respectively. Also hygroscopicity of yeasts in time was
examined, allowing to check how water ? the main component of the cell ? affects PALS parameters, thus lifetime
of o-Ps were found to change from 1.2 to 1.4 ns (shorter-lived component) for the dried yeasts. The time suffi cient
to hydrate the cells was found below 10 hours. In the presence of liquid water, an indication of reorganization of
yeast in the molecular scale was observed. Microscopic images of the lyophilized, dried, and wet yeasts with best
possible resolution were obtained using inverted microscopy (IM) and environmental scanning electron microscopy
(ESEM) methods. As a result, visible changes to the surface of the cell me mbrane were observed in ESEM images.
Reconstruction of hit time and hit position of annihilation quanta in the J-PET detector usi ng the Mahalanobis distance
N. G. Sharma, M. Silarski, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
The J-PET detector being developed at Jagiellonian University, is a Positron Emission Tomograph composed of the long strips of polymer scintillators. At the same time it is a detector system which will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit-time and hit-position of the gamma quantum. In order to take advantage of this fact a dedicated sampling front-end electronics which enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity we use the Mahalanobis distance. The achievable position and time-resolution depends on number and values of the threshold levels at which the signal is sampled. A reconstruction method, as well as preliminary results are presented and discussed.
PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix
A. Wieczorek, B. Zgardzińska, B. Jasińska, M. Gorgol, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, W. Wiślicki, M. Zieliński, P. Moskal
abstract
The polystyrene dopped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter, prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260 K, 283 K and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.
Processing optimization with parallel computing for the J-PET scanner
W. Krzemień, M. Bała, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, K. Stola, A. Strzelecki, D. Trybek, Anna Wieczorek, W. Wiślicki, M. Zieliński, B. K. Zgardzińska, P. Moskal
abstract
The Jagiellonian-PET (J-PET) collaboration is developing a prototype TOF-PET detector based on long polymer scintillators. This novel approach exploits the excellent time properties of the plastic scintillators, which permit very precise time measurements. The very fast, FPGA-based front-end electronics and the data acquisition system, as well as, low- and high-level reconstruction algorithms were specially developed to be used with the J-PET scanner. The TOF-PET data processing and reconstruction are time and resource demanding operations, especially in case of a large acceptance detector, which works in triggerless data acquisition mode. In this article, we discuss the parallel computing methods applied to optimize the data processing for the J-PET detector. We begin with general concepts of parallel computing and then we discuss several applications of those techniques in the J-PET data processing.
K*(892)(+) production in proton-proton collisions at E-beam=3.5 GeV
G. Agakishiev, O. Arnold, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, M. Bohmer, JL. Boyard, P. Cabanelas, S. Chernenko, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frolich, T. Galatyuk, JA. Garzon, R. Gernhauser, K. Gobel, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, T. Heinz, T. Hennino, R. Holzmann, A. Ierusalimov, I. Iori, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, F. Krizek, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, D. Mihaylov, C. Muntz, R. Munzer, L. Naumann, YC. Pachmayer, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, et al.
abstract
We present results on the K*(892)(+) production in proton-proton collisions at a beam energy of E = 3.5 GeV, which is hitherto the lowest energy at which this mesonic resonance has been observed in nucleon-nucleon reactions. The data are interpreted within a two-channel model that includes the three-body production of K*(892)(+) associated with the Lambda or Sigma hyperon. The relative contributions of both channels are estimated. Besides the total cross section sigma(p + p -> K*(892)(+) + X) = 9.5 +/- 0.9(-0.9)(+1.1) +/- 0.7 mu b, which adds a new data point to the excitation function of the K*(892)+ production in the region of low excess energy, transverse momenta and angular spectra are extracted and compared with the predictions of the two-channel model. The spin characteristics of K*(892)(+) are discussed as well in terms of the spin-alignment.
Multiple Scattering and Accidental Coincidences in the J-PET Detector Simulated Using GATE Package
P. Kowalski, P. Moskal, W. Wislicki, L. Raczynski, T. Bednarski, P. Bialas, J. Bulka, E. Czerwinski, A. Gajos, A. Gruntowski, D. Kaminska, L. Kaplon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemien, E. Kubicz, S. Niedzwiecki, M. Palka, Z. Rudy, P. Salabura, NG. Sharma, M. Silarski, A. Slomski, J. Smyrski, A. Strzelecki, A. Wieczorek, I. Wochlik, M. Zielinski, N. Zon
abstract
Novel positron emission tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta.
A pilot study of the novel J-PET plastic scintillator with 2-(4-styrylphenyl)benzoxazole as a wavelength shifter
A. Wieczorek, P. Moskal, Sz. Niedźwiecki, T. Bednarski, P. Białas, E. Czerwiński, A. Danel, A. Gajos, A. Gruntowski, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, T. Uchacz, W. Wiślicki, M. Zieliński, N. Zoń
abstract
For the first time a molecule of 2-(4-styrylphenyl)benzoxazole containing benzoxazole and stilbene groups is applied as a scintillator dopant acting as a wavelength shifter. In this article a light yield of the plastic scintillator, prepared from styrene doped with 2 wt% of 2,5-diphenylbenzoxazole and 0.03 wt% of 2-(4-styrylphenyl)benzoxazole, is determined to be as large as 60% ? 2% of the anthracene light output. There is a potential to improve this value in the future by the optimization of the additives concentrations.
Compressive sensing of signals generated in plastic scintillators in a novel J-PET instrument
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
The J-PET scanner, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The discussed detector offers improvement of the Time of Flight (TOF) resolution due to the use of fast plastic scintillators and dedicated electronics allowing for sampling in the voltage domain of signals with durations of few nanoseconds. In this paper we show that recovery of the whole signal, based on only a few samples, is possible. In order to do that, we incorporate the training signals into the Tikhonov regularization framework and we perform the Principal Component Analysis decomposition, which is well known for its compaction properties. The method yields a simple closed form analytical solution that does not require iterative processing. Moreover, from the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This is the key to introduce and prove the formula for calculations of the signal recovery error. In this paper we show that an average recovery error is approximately inversely proportional to the number of acquired samples.
Analysis framework for the J-PET scanner
W. Krzemień, A. Gajos, A. Gruntowski, K. Stola, D. Trybek, T. Bednarski, P. Białas, E. Czerwiński, D. Kamińska, L. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, E. Kubicz, P. Moskal, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, N. Zoń
abstract
J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The Framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.
Hit time and hit position reconstruction in the J-PET detector based on a library of averaged model signals
P. Moskal, N.G.Sharma, M.Silarski, T. Bednarski, P. Białas, J. Bułka, E. Czerwiński, A. Gajos, D. Kamińska, L. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, I. Wochlik, M. Zieliński, N. Zoń
abstract
n this article we present a novel method of hit time and hit position reconstruction in long scintillator detectors. We take advantage of the fact that for this kind of detectors amplitude and shape of registered signals depends strongly on the position where particle hit the detector. The reconstruction is based on determination of the degree of similarity between measured and averaged signals stored in a library for a set of well-defined positions along the scintillator. Preliminary results of validation of the introduced method with experimental data obtained by means of the double strip prototype of the J-PET detector are presented.
GPU accelerated image reconstruction in a two-strip J-PET tomograph
P. Białas, J. Kowal, A. Strzelecki, T. Bednarski, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, P. Moskal, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Wieczorek, W. Wiślicki, M. Zieliński, N. Zoń
abstract
We present a fast GPU implementation of the image reconstruction routine, for a novel two strip PET detector that relies solely on the time of flight measurements.
Highlights of Resonance Measurements With HADES
E. Epple, J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, K. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, et al.
abstract
This contribution aims to give a basic overview of the latest results regarding the production of resonances in different collision systems. The results were extracted from experimental data collected with HADES that is a multipurpose detector located at the GSI Helmholtzzentrum, Darmstadt. The main points discussed here are: the properties of the strange resonances Lambda(1405) and Sigma(1385), the role of Delta's as a source of pions in the final state, the production dynamics reflected in form of differential cross sections, and the role of the phi meson as a source for K- particles.
Investigating hadronic resonances in pp interactions with HADES
W. Przygoda, J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlavac, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, B. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, et al.
abstract
In this paper we report on the investigation of baryonic resonance production in proton-proton collisions at the kinetic energies of 1.25 GeV and 3.5 GeV, based on data measured with HADES. Exclusive channels np pi(+) and ppp(0) as well as ppe(+) e(-) were studied simultaneously in the framework of a one-boson exchange model. The resonance cross sections were determined from the one-pion channels for Delta(1232) and N(1440) (1.25 GeV) as well as further Delta and N* resonances up to 2 GeV/c(2) for the 3.5 GeV data. The data at 1.25 GeV energy were also analysed within the framework of the partial wave analysis together with the set of several other measurements at lower energies. The obtained solutions provided the evolution of resonance production with the beam energy, showing a sizeable non-resonant contribution but with still dominating contribution of Delta(1232)P-33. In the case of 3.5 GeV data, the study of the ppe(+)e(-) channel gave the insight on the Dalitz decays of the baryon resonances and, in particular, on the electromagnetic transition form-factors in the time-like region. We show that the assumption of a constant electromagnetic transition form-factors leads to underestimation of the yield in the dielectron invariant mass spectrum below the vector mesons pole. On the other hand, a comparison with various transport models shows the important role of intermediate rho production, though with a large model dependency. The exclusive channels analysis done by the HADES collaboration provides new stringent restrictions on the parameterizations used in the models.
A novel method for the line-of-response and time-of-flight reconstruction in TOF-PET detectors based on a library of synchronized model signals
P. Moskal, N. Zoń, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński
abstract
A novel method of hit time and hit position reconstruction in scintillator detectors is described. The method is based on comparison of detector signals with results stored in a library of synchronized model signals registered for a set of well-defined positions of scintillation points. The hit position is reconstructed as the one corresponding to the signal from the library which is most similar to the measurement signal. The time of the interaction is determined as a relative time between the measured signal and the most similar one in the library. A degree of similarity of measured and model signals is defined as the distance between points representing the measurement- and model-signal in the multi-dimensional measurement space. Novelty of the method lies also in the proposed way of synchronization of model signals enabling direct determination of the difference between time-of-flights (TOF) of annihilation quanta from the annihilation point to the detectors. The introduced method was validated using experimental data obtained by means of the double strip prototype of the J-PET detector and 22Na sodium isotope as a source of annihilation gamma quanta.The detector was built out from plastic scintillator strips with dimensions of 5 mm x 19 mm x 300 mm, optically connected at both sides to photomultipliers,from which signals were sampled by means of the Serial Data Analyzer.Using the introduced method, the spatial and TOF resolution of about 1.3 cm (?) and 125 ps (?) were established, respectively.
Medium effects in proton-induced K-0 production at 3.5 GeV
G. Agakishiev, O. Arnold, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, M. Bohmer, JL. Boyard, P. Cabanelas, S. Chernenko, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, K. Gobel, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumbcridzc, T. Hcinz, T. Hcnnino, R. Holzmann, A. Icrusalimov, I. Iori, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, F. Krizek, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, YC. Pachmayer, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, et al.
abstract
We present the analysis of the inclusive K-0 production in p + p and p + Nb collisions measured with the HADES detector (GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt) at a beam kinetic energy of 3.5 GeV. Data are compared to the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model. The data suggest the presence of a repulsive momentum-dependent kaon potential as predicted by the chiral perturbation theory (ChPT). For the kaon at rest and at normal nuclear density, the ChPT potential amounts to approximate to 35 MeV. A detailed tuning of the kaon production cross sections implemented in the model has been carried out to reproduce the experimental data measured in p + p collisions. The uncertainties in the parameters of the model were examined with respect to the sensitivity of the experimental results from p + Nb collisions to the in-medium kaon potential.
Test of a single module of the J-PET scanner based on plastic scintillators
P. Moskal, S. Niedzwiecki, T. Bednarski, E. Czerwinski, L. Kaplon, E. Kubicz, I. Moskal, M. Pawlik-Niedzwiecka, NG. Sharma, M. Silarski, M. Zielinski, N. Zon, P. Bialas, A. Gajos, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemien, M. Molenda, M. Palka, L. Raczynski, Z. Rudy, P. Salabura, A. Slomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wislicki
abstract
A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5 x 19 x 300 mm(3)) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the Ge-68 isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (sigma) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to sigma(E)/E approximate to 0.044/root E(MeV) and corresponds to the (sigma(E)/E of 7.5% at the Compton edge. (C) 2014 Elsevier B.V. All rights reserved.
Time of flight measurement in heavy-ion collisions with the HADES RPC TOF wall
G. Kornakov, I. Arnold, ET. Atomssa, C. Behnke, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, K. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, V. Pechenov, O. Pechenova, V. Petousis, et al.
abstract
This work presents the analysis of the performance of the RPC ToF wall of the HADES, located at GSI Helmholtzzentrum fur Schwerionenforschung, Darmstadt. The behavior of the detector is studied in Au+Au collisions at 1.23 AGeV. A main characteristic of the detector is that all the active areas were designed to be electrically shielded in order to operate in high occupancies of the chambers. Here we show the achieved performance regarding efficiency and timing capabilities at different occupancies of this special design after the applied offline corrections to the data. Also the stability of the intrinsic time resolution over time of data taking is presented.
Test of a single module of the J-PET scanner based on plastic scintillators
P. Moskal, Sz. Niedźwiecki, T. Bednarski, E. Czerwiński, Ł. Kapłon, E. Kubicz, I. Moskal, M. Pawlik-Niedźwiecka, N.G. Sharma, M. Silarski, M. Zieliński, N. Zoń, P. Białas, A. Gajos, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, M. Pałka, L. Raczyński, Z. Rudy, P. Salabura, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki
abstract
Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this article we report on tests of a single detection module built out from BC-420 plastic scintillator strip (with dimensions of 5x19x300mm^3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50ps intervals. The time resolution of the prototype module was established to be better than 80ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93cm (sigma) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to sigma(E)/E = 0.044/sqrt(E[MeV]) and corresponds to the sigma(E)/E of 7.5% at the Compton edge.
Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511 keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps (sigma).
Associate K-0 production in p plus p collisions at 3.5 GeV: The role of Delta(1232)(++)
G. Agakishiev, O. Arnold, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, M. Bohmer, JL. Boyard, P. Cabanelas, S. Chernenko, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, K. Gobel, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, T. Heinz, T. Hennino, R. Holzmann, A. Ierusalimov, I. Iori, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, F. Krizek, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, T. Kunz, A. Kurepin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, YC. Pachmayer, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, et al.
abstract
An exclusive analysis of the four-body final states Lambda + p + pi(+) + K-0 and Sigma(0) + p + pi(+) + K-0 measured with HADES for p + p collisions at a beam kinetic energy of 3.5 GeV is presented. The analysis uses various phase space variables, such as missing mass and invariant mass distributions, in the four-particle event selection (p,pi(+),pi(+),pi(-)) to find cross sections of the different production channels, contributions of the intermediate resonances Delta(++) and Sigma(1385)(+), and corresponding angular distributions. A dominant resonant production is seen, where the reaction Lambda + Delta(++) + K-0 has a cross section about ten times higher (29.45 +/- 0.08(-1.46)(+1.67) +/- 2.06 mu b) than the analogous nonresonant reaction (2.57 +/- 0.02(-1.98)(+0.21) +/- 0.18 mu b). A similar result is obtained in the corresponding Sigma(0) channels with 9.26 +/- 0.05(-0.31)(+1.41) +/- 0.65 mu b in the resonant and 1.35 +/- 0.02(-1.35)(+0.10) +/- 0.09 mu b in the nonresonant reactions.
Computing support for advanced medical data analysis and imaging
W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, S. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
We discuss computing issues for data analysis and image reconstruction of PET-TOF medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on the grid and cloud concepts for distributed processing is proposed and critically discussed.
A novel method based solely on FPGA units enabling measurement of time and charge of analog signals in Positron Emission Tomography
M. Pałka, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article presents a novel technique for precise measurement of time and charge based solely on FPGA (Field Programmable Gate Array) device and few satellite discrete electronic components used in Positron Emission Tomography (PET). Described approach simplifies electronic circuits, reduces the power consumption, lowers costs, merges front-end electronics with digital electronics and also makes more compact final design. Furthermore, it allows to measure time when analog signals cross a reference voltage at different threshold levels with a very high precision of ? 10ps (rms) and thus enables sampling of signals in a voltage domain.
A novel method for calibration and monitoring of time synchronization of TOF-PET scanners by means of cosmic rays
M. Silarski, E. Czerwiński, T. Bednarski, P. Moskal, P. Białas, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
All of the present methods for calibration and monitoring of TOF-PET scanner detectors utilize radioactive isotopes such as e.g. 22Na or 68Ge, which are placed or rotate inside the scanner. In this article we describe a novel method based on the cosmic rays application to the PET calibration and monitoring methods. The concept allows to overcome many of the drawbacks of the present methods and it is well suited for newly developed TOF-PET scanners with a large longitudinal field of view. The method enables also monitoring of the quality of the scintillator materials and in general allows for the continuous quality assurance of the PET detector performance.
3D PET image reconstruction based on the maximum likelihood estimation method (MLEM) algorithm
A. Słomski, Z. Rudy, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, P. Salabura, N. G. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
A positron emission tomography (PET) scan does not measure an image directly. Instead, a PET scan measures a sinogram at the boundary of the field-of-view that consists of measurements of the sums of all the counts along the lines connecting the two detectors. Because there is a multitude of detectors built in a typical PET structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Significant improvement in PET image quality was achieved with the introduction of iterative reconstruction techniques. This was realized approximately 20 years ago (with the advent of new powerful computing processors). However, three-dimensional imaging still remains a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines of response and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.
Trigger-less and reconfigurable data acquisition system for positron emission tomography
G. Korcyl, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article is focused on data acquisition system (DAQ) designed especially to be used in positron emission tomography (PET) or single-photon emission computed tomography. The system allows for continuous registration of analog signals during measurement. It has been designed to optimize registration and processing of the information carried by signals from the detector system in PET scanner. The processing does not require any rejection of data with a trigger system. The proposed system possesses also an ability to implement various data analysis algorithms that can be performed in real time during data collection.
Determination of the map of efficiency of the Jagiellonian Positron Emission Tomograph (J-PET) detector with the GATE package
P. Kowalski, L. Raczyński, T. Bednarski, P. Białas, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
A novel PET detector consisting of strips of polymer scintillators is being developed by the J-PET Collaboration. The map of efficiency and the map of geometrical acceptance of the 2-strip J-PET scanner are presented. Map of efficiency was determined using the Monte Carlo simulation software GATE based on GEANT4. Both maps were compared using method based on the chi2 test.
Plastic scintillators for positron emission tomography obtained by the bulk polymerization method
Ł. Kapłon, A. Kochanowski, M. Molenda, P. Moskal, A. Wieczorek, T. Bednarski, P. Białas, E. Czerwiński, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillators, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.
J-PET analysis framework for the prototype TOF-PET detector
W. Krzemień, M. Silarski, K. Stola, D. Trybek, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
Novel TOF-PET scanner solutions demand, apart from the state of the art detectors, software for fast processing of the gathered data, monitoring of the whole scanner and reconstruction of the PET image. In this article we present an analysis framework for the novel STRIP-PET scanner developed by the J-PET collaboration in the Institute of Physics of the Jagiellonian University. This software is based on the ROOT package used in many particle physics experiments.
Database and data structure for the novel TOF-PET detector developed for J-PET project
E. Czerwiński, M. Zieliński, T. Bednarski, P. Białas, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W.Wiślicki, N. Zoń
abstract
The complexity of the hardware and the amount of data collected during the PET imaging process require application of modern methods of efficient data organization and processing. In this article we will discuss the data structures and the flow of collected data from the novel TOF-PET medical scanner which is being developed at the Jagiellonian University. The developed data format reflects: registration process of the gamma quanta emitted from positron-electron annihilation, Front-End Electronic (FEE) structure and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.
Calibration of photomultipliers gain used in the J-PET detector
T. Bednarski, E. Czerwiński, P. Moskal, P. Białas, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Photomultipliers are commonly used in commercial PET scanner as devices which convert light produced in scintillator by gamma quanta from positron-electron annihilation into electrical signal. For proper analysis of obtained electrical signal, a photomultiplier gain curve must be known, since gain can be significantly different even between photomultipliers of the same model. In this article we describe single photoelectron method used for photomultipliers calibration applied for J-PET scanner, a novel PET detector being developed at the Jagiellonian University. Description of calibration method, an example of calibration curve and gain of few R4998 Hamamatsu photomultipliers are presented.
List-mode reconstruction in 2D strip PET
P. Białas, J. Kowal, A. Strzelecki, T. Bednarski, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, P. Moskal, S. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Using a theory of list-mode maximum likelihood
expectation-maximization (MLEM) algorithm, in this contribution,
we present a derivation of the system response
kernel for a novel positron emission tomography (PET)
detector based on plastic scintillators.
Measurement of the quasi free np -> np pi(+)pi(-) and np -> pp pi(-)pi(0) reactions at 1.25 GeV with HADES
A. Kurilkin, O. Arnold, ET. Atomssa, C. Behnke, A. Belyaev, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, K. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Ku, A. Kugler, T. Kunz, A. Kurepin, P. Kurilkine, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, V. Pechenov, O. Pechenova, et al.
abstract
We present the results of two-pion production in tagged quasi-free np collisions at a deutron incident beam energy of 1.25 GeV/c measured with the High-Acceptance Di-Electron Spectrometer (HADES) installed at GSI. The specific acceptance of HADES allowed for the first time to obtain high-precision data on pi(+)pi(-) and pi(-)pi(0) production in np collisions in a region corresponding to large transverse momenta of the secondary particles. The obtained differential cross section data provide strong constraints on the production mechanisms and on the various baryon resonance contributions (Delta Delta, N(1440), N(1520), Delta(1600)). The invariant mass and angular distributions from the np -> np pi(+)pi(-) and np -> pp pi(-)pi(0) reactions are compared with different theoretical model predictions.
Electromagnetic Calorimeter for HADES Experiment
P. Rodriguez-Ramos, L. Chlad, E. Epple, L. Fabbietti, T. Galatyuk, M. Golubeva, F. Guber, S. Hlavac, A. Ivashkin, M. Kajetanowic, B. Kardan, W. Koenig, G. Korcyl, A. Kugler, K. Lapidus, S. Linev, E. Lisowski, A. Neiser, O. Ott, O. Otte, O. Pethukov, J. Pietraszko, A. Reshetin, A. Rost, P. Salabura, YG. Sobolev, O. Svoboda, A. Thomas, P. Tlusty, M. Traxler
abstract
Electromagnetic calorimeter (ECAL) is being developed to complement dilepton spectrometer HADES. ECAL will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 AGeV on the beam of future accelerator SIS100@FAIR. We will report results of the last beam test with quasi-monoenergetic photons carried out in MAMI facility at Johannes Gutenberg Universitat Mainz.
HADES results in elementary reactions
B. Ramstein, J. Adamczewski-Musch, O. Arnold, ET. Atomssa, C. Behnke, JC. Berger-Chen, J. Biernat, A. Blanco, C. Blume, M. Bohmer, P. Bordalo, S. Chernenko, C. Deveaux, A. Dybczake, E. Epple, L. Fabbietti, O. Fateev, P. Fonteb, C. Franco, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, S. Hlava, C. Hohne, R. Holzmann, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, K. Kardan, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, H. Kuc, A. Kugler, T. Kunz, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, T. Mahmoud, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, et al.
abstract
Recent results obtained with the HADES experimental set-up at GSI are presented with a focus on dielectron production and strangeness in pp and quasi-free np reactions. Perspectives related to the very recent experiment using the pion beam at GSI are also discussed.
Tracking with Straw Tubes in the PANDA Experiment
M. Bragadireanu, D. Pietreanu, ME. Vasile, M. Idzik, D. Przyborowski, P. Kulessa, K. Pysz, J. Biernat, S. Jowzaee, G. Korcyl, M. Palka, P. Salabura, J. Smyrski, D. Bettoni, E. Fioravanti, I. Garzia, M. Savrie, P. Gianotti, V. Lucherini, E. Pace, M. Mertens, H. Ohm, S. Orfanitski, J. Ritman, V. Serdyuk, P. Wintz, S. Dobbs, A. Tomaradze, GL. Boca, S. Costanza, P. Genova, L. Lavezzi, P. Montagna, A. Rotondi, S. Spataro
abstract
The PANDA spectrometer will be built at the FAIR facility at Darmstadt (Germany) to perform accurate tests of the strong interaction through (p) over barp and (p) over barA annihilation studies. The charged particle tracking at PANDA will be done using both solid state and gaseous detectors. Among the latter, two straw tube detector systems will be built [ 1]. The cylindrical, central straw tube tracker features a high spatial and momentum resolution for a wide range of particle momenta from about 8 GeV/c down to a few 100 MeV/c, together with particle identification in the momentum region below about 1 GeV/c by measuring the specific energy-loss. A new technique, based on self-supporting straw double layers with intrinsic wire tension developed for the COSY-TOF straw tracker [ 2], has been adopted for the PANDA trackers. The development of the readout electronics for the straw tubes is ongoing. Prototypes have been produced and used to instrument straw tube modules that have been tested with cosmic rays and proton beams. Design issues of the PANDA straw tubes, together with the results of the prototype tests are presented.
Low mass dielectrons radiated off cold nuclear matter measured with HADES
M. Lorenz, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, S. Chernenko, C. Dritsa, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, C. Hohne, R. Holzmann, P. Huck, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, et al.
abstract
The High Acceptance DiElectron Spectrometer HADES [1] is installed at the Helmholtzzentrum fur Schwerionenforschung (GSI) accelerator facility in Darmstadt. It investigates dielectron emission and strangeness production in the 1-3 AGeV regime. A recent experiment series focusses on medium-modifications of light vector mesons in cold nuclear matter. In two runs, p + p and p + Nb reactions were investigated at 3.5 GeV beam energy; about 9 . 10(9) events have been registered. In contrast to other experiments the high acceptance of the HADES allows for a detailed analysis of electron pairs with low momenta relative to nuclear matter, where modifications of the spectral functions of vector mesons are predicted to be most prominent. Comparing these low momentum electron pairs to the reference measurement in the elementary p + p reaction, we find in fact a strong modification of the spectral distribution in the whole vector meson region.
In-medium hadron properties measured with HADES
J. Pietraszko, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, S. Chernenko, C. Dritsa, A. Dybczak, E. Epples, L. Fabbietti, O. Fateev, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, C. Hohne, R. Holzmann, P. Huck, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, et al.
abstract
Many QCD based and phenomenological models predict changes of hadron properties in a strongly interacting environment. The results of these models differ significantly and the experimental determination of hadron properties in nuclear matter is essential. In this paper we present a review of selected physics results obtained at GSI Helmholtzzentrum fur Schwerionenforschung GmbH by HADES (High-Acceptance Di-Electron Spectrometer). The e(+)e(-) pair emission measured for proton and heavy-ion induced collisions is reported together with results on strangeness production. The future HADES activities at the planned FAIR facility are also discussed.
Simulations of gamma quanta scattering in a single module of the J-PET detector
K. Szymański, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, P. Witkowski, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article describes simulations of scattering of annihilation gamma quanta in a strip of plastic scintillator. Such strips constitute basic detection modules in a newly proposed Positron Emission Tomography which utilizes plastic scintillators instead of inorganic crystals. An algorithm simulating chain of Compton scatterings was elaborated and series of simulations have been conducted for the scintillator strip with the cross section of 5 mm x 19 mm. Obtained results indicate that secondary interactions occur only in the case of about 8% of events and out of them only 25% take place in the distance larger than 0.5 cm from the primary interaction. It was also established that light signals produced at primary and secondary interactions overlap with the delay which distribution is characterized by FWHM of about 40 ps.
Application of WLS strips for position determination in Strip PET tomograph based on plastic scintillators
J. Smyrski, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
A method of determination of a gamma quantum absorption point in a plastic scintillator block using a matrix of wavelength-shifting (WLS) strips is proposed. Application of this method for improvement of position resolution in newly proposed PET detectors based on plastic scintillators is presented. The method enables to reduce parallax errors in reconstruction of images which occurs in the presently used Positron Emission Tomography scanners.
pK(+)Lambda final state: Towards the extraction of the ppK(-) contribution
L. Fabbietti, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, S. Chernenko, C. Dritsa, A. Dybczak, E. Epple, O. Fateev, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, C. Hohne, R. Holzmann, P. Huck, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, et al.
abstract
The reaction p(@3.5 GeV) + p -> p + Lambda + K+ can be studied to search for the existence of kaonic bound states like ppK(-) leading to this final state. This effort has been motivated by the assumption that in p + p collisions the Lambda(1405) resonance can act as a doorway to the formation of the kaonic bound states. The status of this analysis within the HADES Collaboration, with particular emphasis on the comparison to simulations, is shown in this work and the deviation method utilized by the DISTO Collaboration in a similar analysis is discussed. The outcome suggests the employment of a partial wave analysis do disentangle the different contributions to the measured pK(+)Lambda final state. (c) 2013 Elsevier B.V. All rights reserved.
Particle identification using the time-over-threshold measurements in straw tube detectors
S. Jowzaee, E. Fioravanti, P. Gianotti, M. Idzik, G. Korcyl, M. Palka, D. Przyborowski, K. Pysz, J. Ritman, P. Salabura, M. Savrie, J. Smyrski, P. Strzempek, P. Wintz
abstract
The identification of charged particles based on energy losses in straw tube detectors has been simulated. The response of a new front-end chip developed for the PANDA straw tube tracker was implemented in the simulations and corrections for track distance to sense wire were included. Separation power for p-K, p-pi and K-pi pairs obtained using the time-over-threshold technique was compared with the one based on the measurement of collected charge. (C) 2012 Elsevier B.V. All rights reserved.
TOF-PET detector concept based on organic scintillators
P. Moskal, T. Bednarski, P. Białas, M. Ciszewska, E. Czerwiński, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka-Cupiał, G. Korcyl, W. Krzemień, K. Łojek, J. Majewski, W. Migdał, M. Molenda, S. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, M. Silarski, A. Słomski, J. Smyrski, J. Zdebik, M. Zieliński
abstract
In this contribution we present a new concept of the large acceptance detector systems based on organic scintillators which may allow for simultaneous diagnostic of large fraction of the human body. Novelty of the concept lies in employing large blocks of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes.
Strip-PET: a novel detector concept for the TOF-PET scanner
P. Moskal, T. Bednarski, P. Białas, M. Ciszewska, E. Czerwiński, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka-Cupiał, G. Korcyl, W. Krzemień, K. Łojek, J. Majewski, W. Migdał, M. Molenda, S. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, M. Silarski, A. Słomski, J. Smyrski, J. Zdebik, M. Zieliński
abstract
We briefly present a design of a new PET scanner based on
strips of polymer scintillators arranged in a barrel constituting
a large acceptance detector. The solution proposed is based on
the superior timing properties of the polymer scintillators. The
position and time of the reaction of the gamma quanta in the
detector material will be determined based on the time of arrival
of light signals to the edges of the scintillator strips.
Hades experiments: investigation of hadron in-medium properties
P. Salabura, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, S. Chernenko, C. Dritsa, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, R. Holzmann, P. Huck, C. Hohne, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, et al.
abstract
Hadron modifications in nuclear matter are discussed in connection to chiral symmetry restoration and/or hadronic many body effects. Experiments with photon, proton and heavy ion beams are used to probe properties of hadrons embedded in nuclear matter at different temperatures and densities. Most of the information has been gathered for the light vector mesons rho, omega and phi. HADES is a second generation experiment operating at GSI with the main aim to study in-medium modifications by means of dielectron production at the SIS18/Bevelac energy range. Large acceptance and excellent particle identification capabilities allows also for measurements of strangeness production. These abilities combined with the variety of beams provided by the SIS18 allow for a characterization of properties of the dense baryonic matter properties created in heavy ion collisions at these energies. A review of recent experimental results obtained by HADES is presented, with main emphasis on hadron properties in nuclear matter.
The Straw Tube Trackers of the (P)over-barANDA Experiment
P. Gianotti, V. Lucherini, E. Pace, GL. Boca, S. Costanza, P. Genova, L. Lavezzi, P. Montanga, A. Rotondi, M. Bragadireanu, ME. Vasile, D. Pietreanu, J. Biernat, S. Jowzaee, G. Korcyl, M. Palka, P. Salabura, J. Smyrski, T. Fiutowski, M. Idzik, D. Przyborowski, K. Korcyl, P. Kulessa, K. Pysz, S. Dobbs, A. Tomaradze, D. Bettoni, E. Fioravanti, I. Garzia, M. Savrie, V. Kozlov, M. Mertens, H. Ohm, S. Orfanitski, J. Ritman, V. Serdyuk, P. Wintz, S. Spataro
abstract
The (P) over bar ANDA experiment will be built at the FAIR facility at Darmstadt (Germany) to perform accurate tests of the strong interaction through (p) over barp and (p) over barA annihilation's studies. To track charged particles, two systems consisting of a set of planar, closed-packed, self-supporting straw tube layers are under construction. The (P) over bar ANDA straw tubes will have also unique characteristics in term of material budget and performance. They consist of very thin mylar-aluminized cathodes which are made self-supporting by means of the operation gas-mixture over-pressure. This solution allows to reduce at maximum the weight of the mechanical support frame and hence the detector material budget. The (P) over bar ANDA straw tube central tracker will not only reconstruct charged particle trajectories, but also will help in low momentum (< 1 GeV) particle identification via dE/dx measurements. This is a quite new approach that <(P)over bar>ANDA tracking group has first tested with detailed Monte Carlo simulations, and then with experimental tests of detector prototypes. This paper addresses the design issues of the (P) over bar ANDA straw tube trackers and the performance obtained in prototype tests.
Strange baryon resonances in pp collisions measured with HADES
J. Siebenson, G. Agakishiev, D. Belver, A. Belyaev, A. Blanco, M. Bohmer, P. Cabanelas, S. Chernenko, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, T. Hennino, R. Holzmann, P. Huck, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Kozuch, A. Krasa, F. Krizek, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, S. Lang, K. Lapidus, T. Liu, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, B. Michalska, J. Michel, C. Muntz, L. Naumann, YC. Pachmayer, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, W. Przygoda, B. Ramstein, et al.
abstract
We present an analysis of the hyperons Lambda(1405) and Sigma(1385)(+) for p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the High Acceptance Di-Electron Spectrometer (HADES). A Lambda(1405) signal could be reconstructed in both charged decay channels Lambda(1405). Sigma(+/-)pi(-/+). The obtained statistics of the Sigma(1385)(+) signal allows also differential studies.
Technical Design Report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
W. Erni, ..., S. Jowzaee, M. Kajetanowicz, B. Kamys, S. Kistryn, G. Korcyl, K. Korcyl, W. Krzemień, A. Magiera, P. Moskal, M. Palka, Z. Rudy, P. Salabura, J. Smyrski, A. Wrońska et al.
abstract
This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole Panda scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
The HADES-at-FAIR project
K. Lapidus, G. Agakishiev, A. Balanda, R. Bassini, C. Behnke, A. Belyaev, A. Blanco, M. Bohmer, P. Cabanelas, N. Carolino, JC. Chen, S. Chernenko, J. Diaz, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, R. Gernhauser, A. Gil, K. Gobel, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, K. Heidel, T. Heinz, T. Hennino, R. Holzmann, P. Huck, J. Hutsch, A. Ierusalimov, I. Iori, A. Ivashkin, M. Jurkovic, B. Kampfer, M. Kajetanowicz, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Kozuch, E. Krebs, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, JS. Lange, M. Liu, T. Liu, L. Lopes, M. Lorenz, G. Lykasov, L. Maier, A. Malakhov, A. Mangiarotti, et al.
abstract
After the completion of the experimental program at SIS18 the HADES setup will migrate to FAIR, where it will deliver high-quality data for heavy-ion collisions in an unexplored energy range of up to 8 A GeV. In this contribution, we briefly present the physics case, relevant detector characteristics and discuss the recently completed upgrade of HADES.
Tracking with Straw Tubes in the PANDA Experiment
P. Gianotti, V. Lucherini, E. Pace, K. Kozlov, H. Ohm, S. Orfanitski, M. Mertens, J. Ritman, M. Roeder, V. Serdyuk, P. Wintz, M. Idzik, D. Przyborowski, S. Jowzaee, M. Kajetanowicz, G. Korcyl, P. Salabura, J. Smyrski, P. Kulessa, K. Pysz, G. Boca, S. Costanza, L. Lavezzi, P. Montagna, A. Rotondi, M. Savrie, O. Levitskaya, A. Kashchuk
abstract
Tracking charged particles is one of the essential tasks of the PANDA experiment, providing information about primary and secondary decay vertices, momenta and type of charged particles emitted after antiproton-proton annihilation, Different tracking devices are under construction for the PANDA spectrometer and among them the two straw tube trackers, A new technique, based on the use of straw tubes operated at over-pressure has been adopted allowing the construction of self-supporting modules avoiding heavy mechanical frames.
The dp-elastic cross section measurement at the deuteron kinetic energy of 2.5 GeV
P. Kurilkin, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, S. Chernenko, C. Dritsa, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, R. Holzmann, P. Huck, C. Hohne, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, et al.
abstract
New results on the differential cross section in deuteron-proton elastic scattering are obtained at the deuteron kinetic energy of 2.5 GeV with the HADES spectrometer. The angular range of 69 degrees - 125 degrees in the center of mass system is covered. The obtained results are compared with the relativistic multiple scattering model calculation using the CD-Bonn deuteron wave function. The data at fixed scattering angles in the c.m. are in qualitative agreement with the constituent counting rules prediction.
Resonance production in p plus p, p plus A and A plus A collisions measured with HADES
M. Lorenz, G. Agakishiev, C. Behnke, D. Belver, A. Belyaev, JC. Berger-Chen, A. Blanco, C. Blume, M. Bohmer, P. Cabanelas, C. Dritsa, A. Dybczak, E. Epple, L. Fabbietti, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, K. Gill, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, S. Harabasz, T. Hennino, R. Holzmann, P. Huck, C. Hohne, A. Ierusalimov, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, G. Korcyl, G. Kornakov, R. Kotte, A. Krasa, E. Krebs, F. Krizek, H. Kuc, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, V. Ladygin, R. Lalik, S. Lang, K. Lapidus, A. Lebedev, L. Lopes, L. Maier, A. Mangiarotti, J. Markert, V. Metag, J. Michel, C. Muntz, R. Munzer, L. Naumann, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, W. Przygoda, B. Ramstein, et al.
abstract
The knowledge of baryonic resonance properties and production cross sections plays an important role for the extraction and understanding of medium modifications of mesons in hot and/or dense nuclear matter. We present and discuss systematics on dielectron and strangeness production obtained with HADES on p+p, p+A and A+A collisions in the few GeV energy regime with respect to these resonances.
DILEPTON PRODUCTION STUDIED WITH THE HADES SPECTROMETER
A. Rustamov, G. Agakishiev, A. Balanda, D. Belver, A. Belyaev, A. Blanco, M. Bohmer, JL. Boyard, P. Cabanelas, E. Castro, S. Chernenko, J. Diaz, A. Dybczak, E. Epple, L. Fabbietti, O. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Frohlich, T. Galatyuk, JA. Garzon, A. Gil, M. Golubeva, D. Gonzalez-Diaz, F. Guber, M. Gumberidze, T. Hennino, R. Holzmann, P. Huck, A. Ierusalimov, I. Iori, A. Ivashkin, M. Jurkovic, B. Kampfer, T. Karavicheva, I. Koenig, W. Koenig, BW. Kolb, A. Kopp, G. Korcyl, GK. Kornakov, R. Kotte, A. Kozuch, A. Krasa, F. Krizek, R. Krucken, H. Kuc, W. Kuhn, A. Kugler, A. Kurepin, A. Kurilkin, P. Kurilkin, P. Kahlitz, V. Ladygin, J. Lamas-Valverde, S. Lang, K. Lapidus, T. Liu, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, B. Michalska, J. Michel, C. Muntz, L. Naumann, et al.
abstract
With the HADES spectrometer at GSI we have studied dilepton production in various collision systems from elementary N+N, over p+A, up to the medium-heavy Ar+KCl system. We have confirmed the puzzling results of the former DLS collaboration at the Bevalac. While we have traced the origin of the excess pair yield in C+C collisions to elementary p+p and n+p processes, we find a significant contribution from the dense phase of the collision in larger Ar+KCl system. From recently obtained e(+)e(-) pair spectra in p+p and p+Nb interactions at 3.5 GeV kinetic beam energy the inclusive production cross sections for neutral pions, eta, omega and rho mesons are extracted for the first time at this beam energy. Furthermore, the production mechanisms of the vector mesons, which are not known at these energies, are investigated. The direct comparison of p+p and p+Nb data allows us to investigate in-medium mass modifications of vector mesons at nuclear ground state density. On the other hand, exclusive production of omega and eta mesons in p+p reactions at 3.5 GeV were studied via their pi(+)pi(-)pi(0) decay channel. Production cross sections and angular distributions for both states were determined.
