Search for polarized antiproton production
D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal
abstract
The production of antiprotons is studied in view of possible polarization effects as basis for a polarized antiproton beam. If antiprotons are produced with some polarization, a quite simple procedure for the generation of a polarized antiproton beam could be worked out. The experiments are performed at the CERN PS test beam T11 where secondary particles with momenta around 3.5 GeV/c are selected. The polarization analysis is performed by measuring the asymmetry of the elastic pp-scattering in the Coulomb-nuclear interference region. The detection system includes Cherenkov and tracking detectors for the particle identification and the 3d track reconstruction. Details on the detection system and the status of the analysis are given.
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.
Lyman-alpha source for laser cooling antihydrogen
G. Gabrielse, B. Glowacz, D. Grzonka, C. D. Hamley, E. A. Hessels, N. Jones, G. Khatri, S. A. Lee, C. Meisenhelder, T. Morrison, E. Nottet, C. Rasor, S. Ronald, T. Skinner, C. H. Storry, E. Tardiff, D. Yost, D. Martinez Zambrano, M. Zieliński
abstract
We present a Lyman-alpha laser developed for cooling trapped antihydrogen. The system is based on a pulsed Ti:sapphire laser operating at 729 nm that is frequency doubled using an LBO crystal and then frequency tripled in a Kr/Ar gas cell. After frequency conversion, this system produces up to 5.7 mW of average power at the Lyman-alpha wavelength. This laser is part of the ATRAP experiment at the antiproton decelerator in CERN.
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.
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.
Drift Chamber Calibration and Track Reconstruction in the P349 Antiproton Polarization Experiment
D. Alfs, B. Głowacz, P. Moskal, M. Zieliński, D. Grzonka, F. Hauenstein, K. Kilian, D. Lersch, J. Ritman, T. Sefzick, W. Oelert, M. Diermaier, E. Widmann, J. Zmeskal, M. Wolke, P. Nadel-Turonski, M. Carmignotto, T. Horn, H. Mkrtchyan, A. Asaturyan, A. Mkrtchyan, V. Tadevosyan, S. Zhamkochyan, S. Malbrunot-Ettenauer, W. Eyrich
abstract
The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.
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.
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.
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.
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.
Possibility of Measurement of Cross Section and Vector Analyzing Powers of p-3He Scattering at the Bronowice Cyclotron Center
I. Ciepał, A. Kozela , B. Głowacz , P. Kulessa , T. Pałasz, I. Skwira-Chalot , B. Włoch
abstract
A new possibility of continuation of few-nucleon dynamics studies at medium energies has appeared together with a new facility at the Institute of Nuclear Physics PAN in Kraków ? The Bronowice Cyclotron Center (CCB). The new cyclotron PROTEUS provides a proton beam in an energy range of 70?230 MeV. Current progress in the theoretical calculations for four-nucleon (4N) systems is a main motivation to investigate p ?3He scattering. Due to the fact that the beam cannot be polarized, the only possibility to study spin observables is to build a polarized 3He target system. A planned experiment assumes the construction of a cylindrical double Pyrex cell with separated pumping and target chambers with an additional polyamide film covering apertures for the passing beam and the reaction products. To polarize 3He gas, the spin-exchange optical pumping method will be used.
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.
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.
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.
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.
Search for polarization effects in the antiproton production process
D. Grzonka, K. Kilian, J. Ritman, T. Sefzick, W. Oelert, M. Diermaier, E. Widmann, J. Zmeskal, B. Glowacz, P. Moskal, M. Zielinski, M. Wolke, P. Nadel-Turonski, M. Carmignotto, T. Horn, H. Mkrtchyan, A. Asaturyan, A. Mkrtchyan, V. Tadevosyan, S. Zhamkochyan, S. Malbrunot-Ettenauer, W. Eyrich, F. Hauenstein, A. Zink
abstract
For the production of a polarized antiproton beam various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.
Drift chamber calibration and particle identification in the P-349 experiment
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink and J. Zmeskal
published in: EPJ Web Conf. 199 (2019) 05017
The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.
Polarization analysis of antiprotons produced in pA collisions
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink and J. Zmeskal
published in: EPJ Web Conf. 199 (2019) 05013
A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.
J-PET: A novel TOF-PET detector based on plastic scintillators
Paweł Moskal, Dominika Alfs, Tomasz Bednarski, Piotr Białas, Catalina Curceanu, Eryk Czerwiński, Kamil Dulski, Aleksander Gajos, Bartosz Głowacz, Marek Gorgol, Beatrix Hiesmayr, Bożena Jasińska, Daria Kamińska, Grzegorz Korcyl, Paweł Kowalski, Tomasz Kozik, Wojciech Krzemień, Ewelina Kubicz, Muhsin Mohammed, Monika Pawlik-Niedźwiecka, Szymon Niedźwiecki, Marek Pałka, Lech Raczyźski, Zbigniew Rudy, Oleksandr Rundel, Neha Gupta Sharma, Michał Silarski, Jerzy Smyrski, Adam Strzelecki, Anna Wieczorek, Wojciech Wiślicki, Bożena Zgardzińska, Marcin Zieliński
published in: IEEE Xplore: Nucl. Sci. Symp., Med. Imag. Conf. and Room-Temp. Semiconductor Detector Workshop, DOI:10.1109/NSSMIC.2016.8069617
Statistical Analysis of Time Resolution of the J-PET Scanner
L. Raczyński, W. Wiślicki, P. Kowalski, W. Krzemień, 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, P. Moskal
published in: IEEE Xplore: Nucl. Sci. Symp., Med. Imag. Conf. and Room-Temp. Semiconductor Detector Workshop, DOI:10.1109/NSSMIC.2016.8069407
Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph
P. Moskal, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kamińska, O. Khreptak, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, J. Smyrski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, and M. Zieliński
published in: EPJ Web Conf. 130 (2016) 07015
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 22Na isotope. Information about the polarization vector of orthopositronium 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 orthopositronium annihilation. In 2016 the first tests and calibration runs are planned, and the
data collection with high statistics will commence in the year 2017.
Status of the analysis for the search of polarization in the antiproton production process
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, and J. Zmeskal
published in: EPJ Web Conf. 130 (2016) 07002
The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.
J-PET detector system for studies of the electron-positron annihilations
M. Pawlik-Niedźwiecka, O. Khreptak, A. Gajos, A. Wieczorek, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzmień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, L. Raczyński, Z. Rudy, M. Silarski, W. Wiślicki, B. Zgardzińska, M. Zieliński, and P. Moskal
published in: EPJ Web Conf. 130 (2016) 07020
Jagiellonian Positron Emission Tomograph (J-PET) has been recently constructed at the Jagiellonian University as a prototype of a cost-effective scanner for the metabolic imaging of the whole human body. J-PET detector is optimized for the measurement of momentum and polarization of photons from the electron-positron annihilations. It is built out of strips of plastic scintillators, forming three cylindrical layers. As detector of gamma quanta it will be used for studies of discrete symmetries and multiparticle entanglement of photons originating from the decays of ortho-positronium atoms.
A novel TOF-PET detector based on plastic scintillators
W. Krzemien, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, ´ B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, 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. Stola, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. K. Zgradzińska, M. Zieliński, P. Moskal
published in: Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) (2015) IEEE
The Jagiellonian-PET (J-PET) collaboration is developing
a novel TOF-PET tomography scanner based mainly
on the timing of signals instead of their amplitudes for the
reconstruction of Lines-of-Response, therefore a very precise time
resolution is one of the main challenges of the project. The
novelty of the concept lies in employing long strips of plastic
scintillators instead of crystals as detectors of the annihilation
quanta. The diagnostic chamber consists of plastic scintillator
strips readout by pairs of photomultipliers arranged axially
around a cylindrical surface. To take advantage of the superior
timing properties of plastic scintillators, the signals are sampled
in the voltage domain with an accuracy of 20 ps by novel ultrafast
electronics, and the data are collected by the FPGA-based
trigger-less data acquisition system. The hit-position and hittime
are reconstructed by the dedicated reconstruction methods
based on the compressing sensing theory and a library of
synchronized model signals. The solutions are subject of sixteen
patent applications. So far, a time-of-flight resolution of 125 ps
(?) was achieved for a double-strip prototype with 30 cm fieldof-view
(FOV). It is by more than a factor of two better than the
TOF resolution achievable in current TOF-PET modalities and
at the same time, the FOV of 30 cm long prototype is significantly
larger with respect to typical commercial PET devices. The axial
geometry gives unique possibilities of combining J-PET with
Computed Tomography or with Magnetic Resonance Imaging,
allowing to perform the simultaneous scan of the patient with
both methods.
