Geant4 investigation of the alpha-beta-gamma detector system used in medical imaging, environmental and nuclear site monitoring

摘要

No commercially available detector system can measure alpha, beta and gamma-rays at the same time and separately with good efficiency, while being cost-effective, portable and offering real-time monitoring. The main purpose of an alpha-beta-gamma detector would be for safety management and nuclear decommissioning in the nuclear industry. This idea for a detector system became more valuable, after Fukushima in Japan, because nuclear waste can contain fission products and transactinide materials which not only emit gamma-rays but also emit alpha and beta particles and in some cases, neutrons. In this research, we investigated the best available alpha-beta-gamma radiation detector materials and their optimum thickness by using Geant4 based GATE simulation. The work revealed a better efficiency result for each radiation type than in previous work. In the simulation, 0.05 mm ZnS(Ag), 3.2 mm plastic scintillator and 1.75 mm BGO were found to be best for the detection and identification of alpha, beta and gamma-rays respectively. In nuclear medicine, this type of detector system could also modify to become a miniaturized radio-guided surgery beta-gamma probe beside of the modification into the robotic surgery. This research result will influence three different areas in imaging technology, homeland security and nuclear industry.