A Comprehensive Simulation Study of a Liquid-Xe Detector for Contraband Detection
| Autor: | Israelashvili, I., Cortesi, M., Vartsky, D., Arazi, L., Bar, D., Caspi, E. N., Breskin, A. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1748-0221/10/03/P03030 |
| Popis: | Recently, a new detector concept, for combined imaging and spectroscopy of fast-neutrons and gamma was presented. It encompasses a liquid-xenon (LXe) converter-scintillator coupled to a UV-sensitive gaseous Thick Gas Electron Multiplier (THGEM)-based imaging photomultiplier (GPM). In this work we present and discuss the results of a systematic computer-simulation study aiming at optimizing the type and performance of LXe converter. We have evaluated the detector spectral response, detection efficiency and spatial resolution for gamma-rays and neutrons in the energy range of 2-15 MeV for 50 mm thick converters consisting of plain LXe volume and LXe-filled capillaries, of Teflon, Polyethylene or hydrogen-containing Teflon (Tefzel). Neutron detection efficiencies for plain LXe, Teflon-capillaries and Tefzel-capillaries converters were about 20% over the entire energy range. In polyethylene capillaries converters the neutron detection efficiency was about 10% at 2 MeV and increased up to about 20% at 14 MeV. Detection efficiencies of gammas in Teflon, Tefzel and polyethylene converters were ~35%. The plain-LXe converter provided the highest gamma-ray detection efficiency, of ~40-50% for 2-15 MeV energy range. Optimization of LXe-filled Tefzel capillary dimensions resulted in spatial resolution of ~1.5mm (FWHM) for neutrons and up to 3.5 mm (FWHM) for gamma-rays. Simulations of radiographic images of various materials using two discrete energy gamma-rays (4.4 MeV and 15.1 MeV) and neutrons in broad energy range (2-10 MeV) were performed in order to evaluate the potential of elemental discrimination. Comment: 29 pages, 17 figures |
| Databáze: | arXiv |
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