分类: 物理学 >> 核物理学 提交时间: 2025-04-11
摘要: The ultra-low background gamma detector designed in this study consists of a compact stacked anti-Compton gamma detector composed of a LaBr₃(Ce) primary crystal and a CsI(Tl) secondary crystal. Based on Geant4 simulations, the anti-coincidence system combining LaBr₃(Ce) and CsI(Tl) crystals was optimized to shield more than 99% of cosmic ray muons while reducing Compton continuum counts and improving the peak-to-Compton ratio, achieving a Compton suppression factor of 5.73 for 137Cs. Geant4 simulations and neural network algorithms were employed to optimize the physical shielding system surrounding the detector. The optimized shielding configuration effectively reduces background counts caused by low- and medium-energy neutrons (below 20 MeV) from cosmic rays by approximately 90% and blocks nearly all gamma rays emitted from laboratory walls. Furthermore, Geant4 simulations estimate that the shielding efficiency of an eight-story building and basement structure for high-energy neutrons (above 20 MeV) from cosmic rays is close to 99%.