Non-invasive detection of hazardous materials with a thermal-to-epithermal neutron station: a feasibility study towards practical application
M. Silarski, K. Dziedzic-Kocurek, K. Drużbicki, R. Reterski, P. Grabowski, M. Krzystyniak
abstract
The growing scale of the devastation that even a single terrorist attack can cause requires more effective methods for the detection of hazardous materials. In particular, there are no solutions for effectively monitoring threats at sea, both for the off-shore infrastructure and ports. Currently, state-of-the-art detection methods determine the density distribution and the shapes of tested subjects but only allow for a limited degree of substance identification. This work aims to present a feasibility study of the possible usage of several methods available on the thermal-to-epithermal neutron station, VESUVIO, at the ISIS neutron and muon spallation source, UK, for the detection of hazardous materials. To this end, we present the results of a series of experiments performed concurrently employing neutron transmission and Compton scattering using melamine, a commonly used explosive surrogate, in order to determine its signal characteristics and limits of detection and quantitation. The experiments are supported by first-principles modelling, providing detailed scrutiny of the material structure and the nuclear dynamics behind the neutron scattering observables.
Effect of temperature on gamma radiation shielding capabilities of bauxite-based refractory concrete
Dominika Madej, Palina Cherkes, Michał Silarski
abstract
This work presents experimental and theoretical studies on gamma-ray shielding capabilities of bauxitecontaining refractory concretes containing new types of inorganic cements belonging to the CaO-Al2O3 (as a reference), CaO-BaO-Al2O3-ZrO2 and CaO-Al2O3-Fe2O3-ZrO2 systems. Firstly, the structure, microstructure, hydration behavior of cements, and thermal stability analysis of hydration products were investigated using X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS) and Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) coupled with Evolved gas analysis-mass spectrometry (EGA-MS). When both Fe2O3 and BaO occur in the form of hydraulic phases as Ca2AlFeO5 and BaAl2O4, respectively, or are structurally incorporated into Ca7ZrAl6O18, the iron and barium modify the nature of hydration products of the CaO-Al2O3-H2O-type. Secondly, three types of concretes containing refractory bauxite aggregates were developed and tested in terms of microstructure, phase content, volumetric density, and weight loss. The maximum weight loss at 110 ?C was associated mainly with the evaporation of the capillary water and the physically adsorbed water (gel water), whereas the chemically bound water (crystal water) occurring in hydrates was released at higher temperatures. Slight variations of the volumetric density of the concretes due to temperature were found. The CCS of the concretes fell within the standard values of ca. 50?100 MPa for shielding refractory concretes. Finally, the effect of temperature on the gamma radiation shielding capabilities of concretes was evaluated using the transmission method for gamma rays with energy in the range of about 81?1400 keV. The obtained values of the linear and mass attenuation coefficients showed improvement in the shielding properties as compared with ordinary concrete. Moreover, the obtained results show no significant effect of elevated temperature on the gamma radiation attenuation properties of the studied bauxite-based refractory concretes which suggests that they may be very useful as shielding materials in severe thermal working conditions.
A new detector concept based on the prompt gamma radiation analysis for In vivo boron monitoring in BNCT
M. Silarski, K. Dziedzic-Kocurek, F. Sobczuk, A. Nykiel, P. Moskal, S. Niedźwiecki, E.Ł. Stępień, M. Szczepanek
abstract
The problem of boron concentration monitoring during the boron neutron capture therapy (BNCT) therapy is one of the main challenges of this type of radiotherapy and is directly related to the nature of the interaction of neutrons with mater. Among the available in vivo methods of boron monitoring positron emission tomography seems to be very promising but it requires a new boron carrier with a ?+ emitter, which is not yet clinically available. An alternative solution may be the prompt gamma radiation analysis (PGRA) based on the secondary radiation emitted in the interaction of neutrons with the patient's tissues. This method requires, however, compact gamma radiation detection systems sustaining high counting rates and characterized by very good energy resolution. In this contribution, we present state-of-the-art solutions for monitoring in BNCT based on PGRA. Moreover, we describe a new concept of such a system based on position-sensitive scintillator detectors equipped with an anti-Compton shield and data analysis supported with modern artificial intelligence algorithms.
Monte Carlo simulations of the underwater detection of illicit war remnants with neutron-based sensors
M. Silarski, P. Sibczyński, O. Bezshyyko, Ł. Kapłon, V. Kumar, S. Niedźwiecki, M. Nowakowski, P. Moskal, S. Sharma, F. Sobczuk
abstract
In recent years, the demand for accurate detection and identification of hazardous substances in an aquatic environment, especially in the Baltic Sea, has seen a significant rise, with a specific focus on unexploded ordnance (UXO) containing conventional explosives and various chemical agents, including, but not limited to, mustard gas, Clark I and II and other lethal compounds. These substances pose a significant threat to human health and the environment, and their identification is crucial for effective demining and environmental protection efforts. In this article, a novel approach for fast, remote, and non-destructive recognition of dangerous substances based on a SABAT sensor installed on an ROV is described. The performance of the proposed neutron-based sensor in an aquatic environment was verified based on a series of Monte Carlo simulations for mustard gas, Clark I and II, and TNT, as they are the most common chemical threats at the bottom of the Baltic Sea. The sensor?s ability to accurately discriminate hazardous and non-hazardous materials is described in the paper in terms of the ratio of chlorine to hydrogen (Cl/H), carbon to oxygen (C/O), and nitrogen to hydrogen (N/H) activation lines integrals. The authors also discussed the future directions of work to validate SABAT (Stoichiometry Analysis By Activation Techniques) sensors in the operational environment.
Performance of the SABAT Neutron-Based Explosives Detector Integrated with an Unmanned Ground Vehicle: A Simulation Study
M. Silarski, M. Nowakowski
abstract
The effective and safe detection of illicit materials, explosives, in particular, is currently of growing importance taking into account the geopolitical situation and increasing risk of a terrorist attack. The commonly used methods of detection are based predominantly on metal detectors and georadars, which show only the shapes of the possible dangerous objects and do not allow for exact identification and risk assessment. A supplementary or even alternative method may be based on neutron activation analysis, which provides the possibility of a stoichiometric analysis of the suspected object and its non-invasive identification. One such sensor is developed by the SABAT collaboration, with its primary application being underwater threat detection. In this article, we present performance studies of this sensor, integrated with a mobile robot, in terms of the minimal detectable quantity of commonly used explosives in different environmental conditions. The paper describes the functionality of the used platform considering electronics, sensors, onboard computing power, and communication system to carry out the manual operation and remote control. Robotics solutions based on modularized structures allow the extension of sensors and effectors that can significantly improve the safety of personnel as well as work efficiency, productivity, and flexibility.
Combined BNCT and PET for theranostics
M. Silarski, K. Dziedzic-Kocurek, M. Szczepanek
abstract
This short review summarizes the issue of boron distribution monitoring in boron neutron capture therapy (BNCT), which remains a serious drawback of this powerful oncological treatment. Here we present the monitoring methods that are presently used with particular emphasis on positron emission tomography (PET) which has the highest potential to be used for the real-time monitoring of boron biodistribution. We discuss the possibility of using present PET scanners to determine the boron uptake in vivo before the BNCT treatment with the use of p-boronphenylalanine (BPA) labeled with 18F isotope. Several examples of preclinical studies and
clinical trials performed with the use of [18F]FBPA are shown. We also discuss shortly the perspectives of using other radiotracers and boron carriers which may significantly improve the boron imaging with the use of the state-of-the-art Total-Body PET scanners providing a theranostic approach in the BNCT.
Design, structure, microstructure and gamma radiation shielding properties of refractory concrete materials containing Ba- and Sr-doped cements
D. Madej , M. Silarski , S. Parzych
abstract
This paper presents an experimental study on the performance of shielding refractory concretes containing new types of cement for use in radiation protection technology. Three concretes with corundum aggregate and special refractory inorganic cements belonging to the CaO-Al2O3, SrO-CaO-Al2O3-ZrO2, SrO-Al2O3 and BaO-CaO-Al2O3-ZrO2 systems were tested. The products formed in the hydration of these binders were detected by SEM-EDS. The linear attenuation coefficients obtained from measurements with ? quanta emitted by the following sources: 22Na, 137Cs, 60Co, 133Ba and 152Eu in the range of 80-1408 keV were determined twice,
firstly after casting and drying (110 oC) of concretes, and secondly after sintering at 1400 oC. Especially, this work fills the gap in the literature providing the gamma rays attenuation properties of cement-containing heat resistant corundum concretes in the energy region between 779 keV and 1112 keV. The experimental setup equipped with the ORTEC GMX25P4-70 High Purity Germanium detector (HPGe) cooled with liquid nitrogen was used for the determination of the gamma-ray linear attenuation coefficients of new materials. The role of the cement on the compressive and bending strengths, pore structure (mercury intrusion porosimetry), phase
composition (XRD, FT-IR), and microstructure (SEM-EDS) of heat-treated concretes was reported. It was found that the incorporation of Sr or Ba and Zr elements with cements improved the attenuation properties of corundum-based concretes, in comparison to the concretes containing Ca. The doping alkaline earth elements i.e. Sr and Ba were chemically bonded within both hydraulic matrix of green concretes and ceramic matrix formed in concrete through sintering at 1400 ?C. Hence, these materials with gamma radiation shielding capacity are designed for special construction applications.
The possibility of an appropriate neutron beam achievement for medical purposes based on GEANT4 calculations
V. Ivanyan
abstract
Proton-induced reactions on the 9Be target are considered as a neutron source, and dependence of neutron yield on target thicknesses is investigated. The optimal thickness of the 9Be target with the design and optimization characteristics of a beam shaping assembly (BSA) for neutron flux from the thick target is studied with the GEANT4 program. To create the realistic model of the experiment, there are inserted two physics lists for nuclear and electromagnetic reactions. To get a high flux of neutrons had taken into account usage of special materials as moderators on the base of (n, 2n) nuclear reactions, as well as, moderators which will decrease the energy of neutrons to achieve the appropriate thermal/epithermal neutron flux. The creation of the system, which must be made from reflectors and moderators, is a necessity to explore the possibility of an appropriate neutron flux achievement for medical purposes, especially for boron neutron capture therapy (BNCT). GEANT4 simulations of this scientific paper describe the study of IBA's C18/18 cyclotron-based neutron sources and its possible usage for therapies.
Hazardous Substance Detection in Water Environments using Neutron Beams: the SABAT Project
M. Silarski
abstract
The ever-increasing risk of terrorist attacks is a stimulus for seeking new, more effective danger detection methods. The article describes new methods of detecting hazardous materials based on the interaction between neutrons and matter. The status of the design of the device for detecting hazardous materials in water environments based on these methods, currently in development at the Jagiellonian University (Kraków, Poland), will be presented as well.
Monte Carlo N-Particle simulations of an underwater chemical threats detection system using neutron activation analysis
P. Sibczyński, M. Silarski, O. Bezshyyko, V. Ivanyan, E. Kubicz, Sz. Niedźwiecki, P. Moskal, J. Raj, S. Sharma and O. Trofimiuk
abstract
In this paper, we present Monte Carlo N-Particle (MCNP) simulations of the system for underwater threat detection using neutron activation analysis developed in the SABAT project. The simulated system is based on a D-T neutron generator emitting 14 MeV neutrons without associated alpha particle detection and equipped with a LaBr3:Ce scintillation detector offering superior energy resolution and allowing for precise identification of activation gamma quanta. The performed simulations show that using the neutron activation analysis method with the designed geometry we are able to identify gamma-rays from hydrogen, carbon, sulphur and chlorine originating from mustard gas in a seawater environment. Our results show that the most efficient way of mustard gas detection is to compare the integral peak ratio for Cl and H.
Underwater detection of dangerous substances: status of the SABAT project
M. Silarski, P. Sibczyński, Sz. Niedźwiecki, S. Sharma, J. Raj, P. Moskal
abstract
The Neutron Activation Analysis (NAA) plays an exceptional role in the modern nuclear engineering, especially in detection of hazardous substances. However, in the aquatic environment, there are still many problems to be solved for effective usage of this technique. We present the status of SABAT (Stoichiometry Analysis By Activation Techniques), one of the projects aiming at the construction of an underwater device for non-invasive threat detection based on the NAA.
Design of the SABAT System for Underwater Detection of Dangerous Substances
M. Silarski, D. Hunik, M. Smolis, S. Tadeja, P. Moskal
abstract
We present status of simulations used to design a novel device for the detection of hazardous substances in the aquatic environment using neutron activation. Unlike the other considered methods based on this technique, we propose to use guides for neutron and gamma quanta which speeds up and simplifies identification. First preliminary results show that both the neutron guide and the ?-ray guide increase the performance of underwater threats detection.
Project of the underwater system for chemical threat detection
M. Silarski, D. Hunik, P. Moskal, M. Smolis, S. Tadeja
abstract
In this article we describe a novel method for the detection of explosives and other hazardous substances in the marine environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides forneutron and gamma quanta which speeds up and simplifies identification. Moreover, it may provide a determination of the density distribution of a dangerous substance. First preliminary results of Monte Carlo simulations dedicated for design of a device exploiting this method are also presented.
