Design and Analysis of a Two-Plane Dual-Particle Imaging System

摘要

The combination of a Compton camera and neutron-scatter camera into a three-plane dual-particle imaging system has been shown to effectively detect and locate fissile threat sources. The main objective of this work is to design an efficient, portable, imaging system capable of localizing neutron and gamma-ray sources. Previous work was aimed at a three-plane system simultaneously imaging neutrons and gamma rays. In that system, the first two planes were made of sixteen liquid-organic scintillation detectors each and the third plane was made of sixteen NaI scintillators. Recent work has focused on a two-plane dual-particle imaging system that provides comparable performance as the three-plane-system while reducing the number of detectors by one-third. Despite eliminating eight liquid scintillators and eight NaI scintillators from the three-plane system, simulations have shown comparable efficiency of total system counts. The two-plane system combines liquid scintillators and NaI in the second (back) plane, with the first (front) plane comprised of liquid scintillators only. Simulations of the two-plane system were performed to estimate its efficiency relative to the three-plane system. In addition, extra attention was paid to various particle-interaction correlations, a key component for accurate imaging. Simulation results were validated with a measurement of a partial two-plane system.