低能中子探测的GEANT4模拟研究

Simulation of Low-energy Neutron Detection based on GEANT4

研究了GEANT4蒙特卡罗模拟程序在低能中子核反应中应用的可行性,新版的GEANT(4.9.4版本)升级了老版本在模拟6Li(n,α)3H核反应道的不足,并且加入了最新截面数据库。对多个核反应道进行了研究,模拟结果显示核反应截面、次级粒子能量和反应的分支比等是正确的;比较了掺6Li材料热中子探测效率的实验结果与MCNP和GEANT4模拟结果,它们基本一致。研究表明,利用GEANT4研究6Li(n,α)3H是可行的,这为进一步研究闪烁体中子探测器的位置分辨率模拟提供了有力支持。

The feasible study of Monte Carlo simulation of low-energy nuclear reaction was performed based on GEANT4. The reaction channel 6 Li（n, a）3H, simulated insufficiently in the old version Geant4, can be given correct results in the new version （version 4.9.4）. New cross section library was added into the program. The study of several nuclear reaction channels shows that the cross sections, the secondary particle energies and the branching ratios are consistent with the experimental values. For doped 6 Li mate- rials, the comparison of thermal neutrons detection efficiencies of experimental results, MCNP and GEANT4 simulations, shows that the simulations are reasonable. From the studies above, it is feasible to simulate the 6Li（n, a）aH reaction with GEANT4. It will provide helpful information for the further study of the position resolution of scintillation neutron detector.