A comprehensive simulation study of a Liquid-Xe detector for contraband detection

Abstract

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 gammarays (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.

First demonstration of a bubble-assisted Liquid Hole Multiplier operation in liquid argon

“…The LAr-based LHM could also be considered in the context of many other fields where LAr is the technology of choice, including Dark Matter searches [21], neutrino physics [9] as well as neutron detection in the contexts of future nuclear-physics experiments (e.g. [22]), homeland security [23] and many more.…”

First results of a large-area cryogenic gaseous photomultiplier coupled to a dual-phase liquid xenon TPC

“…As a final note, GPMs are currently developed for recording primary scintillation in singlephase LXe detectors for neutron and gamma imaging [61,62]. They may also be used in conjunction with Liquid Hole-Multipliers (LHMs), developed in parallel by our group, as potential sensors for large-scale single-phase TPCs [40,63,64].…”

Quantitative discrimination between oil and water in drilled bore cores via Fast-Neutron Resonance Transmission Radiography

“…High position resolution fast neutron detectors required for FNRT have been developed in the last few years (Dangendorf et al, 2008, Brandis et al, 2012, Israelashvili et al 2015. For a review on the prospects of FNRT and its requirements for instrumentation, see Vartsky, 2006. Fig.…”