Geant4中不同物理列表对硼中子俘获治疗剂量分布的影响

Effects of different Geant4 physics lists on boron neutron capture therapy dose calculation

Geant4是基于C++编写的开源蒙特卡洛模拟软件,提供多种包含中子与物质相互作用的物理列表。本研究采用Geant4提供的几种物理列表,对沿中子束方向的总吸收剂量、硼剂量和非硼剂量深度分布进行计算,并与FLUKA进行比较,模拟中子能量从0.025 3 eV到10 MeV。对于整个模拟中子能段,结果显示添加S(α,β)热模型的高精度中子物理列表(Geant4_HP_T)在总吸收剂量、硼剂量和非硼剂量深度分布上均与FLUKA符合很好,初步验证了Genat4能应用于硼中子俘获治疗(BNCT)相关研究。对于低能中子(<1 MeV),S(α,β)热模型对BNCT剂量深度分布的影响较大,QBBC和QGSP_BERT不适用于BNCT剂量分布计算。

Geant4 is an open source Monte Carlo simulation toolkit written in C++,and it provides a variety of physical lists including neutron interactions with matter.Herein several physical lists given by Geant4 are used to calculate the depth distributions of total absorption dose,boron dose and non-Boron dose along the direction of the neutron beam,and the obtained results were compared with FLUKA.The simulation neutron energy is from 0.025 3 eV to 10 MeV.In the studied energy range,the results show that the high-precision neutron physics list(Geant4_HP_T)with S(α,β)thermal model agrees well with FLUKA in the depth distributions of total absorbed dose,boron dose and non-boron dose,which preliminarily verifies that Geant4 can be used in the researches on boron neutron capture therapy(BNCT).For low energy neutrons(<1 MeV),the S(α,β)thermal model has remarkable effects on the depth distribution of BNCT dose,and both QBBC and QGSP_BERT aren't suitable for the calculation of BNCT dose distributions.