Imaging of Fast Neutrons and Gamma-Rays, With Liquid-Xenon/Gaseous-Photomultiplier Detector

摘要

Gamma-ray and fast-neutron imaging was performed with a novel liquid-xenon scintillation detector conceived for homeland-security applications. The 100 mm diameter detector prototype comprised a capillary-filled LXe converter/scintillator, coupled to a triple-THGEM imaging Gaseous Photomultiplier (GPM). Spatial resolutions of 12±2 mm and 10±2 mm (FWHM) were derived from irradiation of a Pb-edge absorber with(~60)Co gamma rays and mixed gamma and fast-neutron from an Am-Be source, respectively. The experimental results are in good agreement with GEANT4 simulations. The calculated ultimate resolutions for a large imaging detector, for the 4.4 and 15.1 MeV gamma and 1-1 lMeV neutrons, relevant for Fast-Neutron Resonant Transmission (FNRT) and Dual-Discrete-Energy Gamma Radiography (DDEGR), are ~2 mm, 4 mm and 1-4 mm (FWHM), respectively. These results indicate the potential applicability of the new detector concept for combined gamma-ray and fast neutron radiographic imaging of large objects.