离子电离与次级反应耦合的蒙特卡罗模拟方法研究与应用

Research on Ionization and Secondary Reaction Coupled Monte Carlo Simulation and Its Application

氘或氚离子在靶物质中电离输运的同时会发生次级反应,为模拟这一过程,开发了耦合蒙特卡罗工具RSMC。程序用详细历史法和浓缩历史法模拟电离过程,调用ENDF或TENDL中D、T核数据计算次级反应,同时使用"强迫次级粒子产生"降方差技巧提高模拟效率。对中子深度分析问题、加速器单能中子源问题和热中子-聚变中子转换靶问题进行研究,验证了RSMC的正确性。

Coupled simulation of deuteron or triton ionization and secondary fusion reac- tion was studied with a Monte Carlo tool named RSMC （Reaction Sequence Monte Carlo）. The detail history and condensed history methods were employed for ionization simulation. Fusion cross sections of deuteron and triton were adopted from ENDF or TENDL. The ＂forced particle production＂ variance reduction technique was also employed to improve the simulation efficiency. As a validation, three types of examples were introduced, including neutron depth profiling, accelerator based mono-energy neutron source, and thermal-to-fusion neutron convertor.