Fast-neutron and gamma-ray imaging with a capillary liquid xenon converter coupled to a gaseous photomultiplier

Abstract

Gamma-ray and fast-neutron imaging was performed with a novel liquid xenon (LXe) scintillation detector read out by a Gaseous Photomultiplier (GPM). The 100 mm diameter detector prototype comprised a capillary-filled LXe converter/scintillator, coupled to a triple-THGEM imaging-GPM, with its first electrode coated by a CsI UV-photocathode, operated in Ne/5%CH4 at cryogenic temperatures.Radiation localization in 2D was derived from scintillation-induced photoelectron avalanches, measured on the GPM's segmented anode. The localization properties of 60 Co gamma-rays and a mixed fastneutron/gamma-ray field from an AmBe neutron source were derived from irradiation of a Pb edge absorber. Spatial resolutions of 12±2 mm and 10±2 mm (FWHM) were reached with 60 Co and AmBe sources, respectively. The experimental results are in good agreement with GEANT4 simulations. The calculated ultimate expected resolutions for our application-relevant 4.4 and 15.1 MeV gamma-rays and 1-15 MeV neutrons are 2-4 mm and ~2 mm (FWHM), respectively. These results indicate the potential applicability of the new detector concept to Fast-Neutron Resonance Radiography (FNRR) and Dual-Discrete-Energy Gamma Radiography (DDEGR) of large objects. and simulations (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc); Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc); Photon detectors for UV, visible and IR photons (gas) (gas-photocathodes, solid-photocathodes); Neutron detectors (cold, thermal, fast neutrons); Gamma detectors (scintillators, CZT, HPG, HgI etc); Detection of contraband and drugs; Detection of explosives 2 1 IntroductionGamma-ray and fast-neutron imaging technologies are currently applied for investigating the content of aviation-and marine-cargo containers, trucks and nuclear waste containers (see for example [1, 2]). MeV-scale x-ray or gamma-ray radiographic inspection methods, such as Dual Energy Bremsstrahlung Radiography (DEBR) [3][4][5] or Dual-Discrete-Energy Gamma Radiography (DDEGR) [6], are used for the detection of concealed Special Nuclear Materials (SNM), providing high-resolution images of object shapes and densities and some selectivity between high-Z elements.DEBR makes use of continuous x-ray spectra, generated by accelerated electrons at two different bombarding energies. DDEGR relies on two discrete gamma-rays, of 4.4 MeV and 15.1 MeV, emitted by the 11 B(d,nγ) 12 C reaction. Fast-neutron imaging methods, such as Fast-Neutron Resonance Radiography (FNRR) [7], utilize a broad neutron spectrum of 2-10 MeV to provide a sensitive probe for identifying low-Z elements such as H, C, N and O; these are the main constituents of explosives and narcotics. In addition, FNRR provides a means for identifying the type of the explosive by determination of the density ratios of its main constituent elements [7]. FNRR has been also proposed recently for determining of oil and water content in drilled formation cores [8].The r...

Novel electron and photon recording concepts in noble-liquid detectors

“…Other applications, besides those discussed in this article, include Compton Cameras in astronomy [102] and medical imaging [103,104] and in large-area detectors for fast-neutron & gamma imaging; e.g. the latter in the field of contraband detection [105].…”

Cryogenic RPWELL: a novel charge-readout element for dual-phase argon TPCs

“…The possibility to use it for amplifying ionization charges in a gas medium at different pressures and temperatures, its robustness, and its low cost turned this detector into a favorable option for several experiments requiring large area coverage at modest spatial and energy resolutions. Some examples are: Ring-Imaging Cherenkov (RICH) detectors [4][5][6], digital hadronic calorimetry (DHCAL) [7,8], rare events searches [9][10][11][12] and civil [13,14] and medical applications [15,16]. For a recent review on THGEM detectors see [3].…”

Organic–inorganic hybrid perovskite scintillators for mixed field radiation detection

“…Sensitive and rapid detection of mixed-field radiation using a single scintillator enables simpler detector geometries, higher detection efficiency, and the acquisition of more elaborate information of the detected particles. [18][19][20][21] However, few materials could fulfill this goal, and even the best scintillator Cs 2 LiYCl 6 :Ce for mixed-field detection is troubled by the slow lifetime component (1000 ns) and limited fast neutron attenuation capability. 22 Recently, lead halide perovskites have emerged as superb materials for various optoelectronic devices, such as solar cells and light-emitting diodes with outstanding efficiency, and X/γ-ray detectors with high sensitivity and low detection limit.…”

“…Sensitive and rapid detection of mixed‐field radiation using a single scintillator enables simpler detector geometries, higher detection efficiency, and the acquisition of more elaborate information of the detected particles 18–21 . However, few materials could fulfill this goal, and even the best scintillator Cs 2 LiYCl 6 :Ce for mixed‐field detection is troubled by the slow lifetime component (1000 ns) and limited fast neutron attenuation capability 22…”