氘-氚中子源辐照旋转靶剂量演化模拟计算

Simulation of evolution of dose of rotary target in a deuterium-tritium neutron source

首次将蒙特卡罗自动建模系统(MCAM)、蒙特卡罗粒子输运程序(MCNP)及自主研发的活化程序BURNDOT相结合,实现了中子输运、材料活化、光子输运模拟计算的耦合。对14MeV氘-氚(D-T)中子源旋转靶室剂量演化分析,计算了氘-氚中子源辐照旋转靶室的瞬发中子、γ三维辐射剂量场分布及连续辐照8小时后缓发γ剂量变化情况,并考察了材质、栅元、主要核素对缓发γ剂量贡献的影响,得到了旋转靶的剂量时空演化规律,把计算结果与欧洲活化程序FISPACT-2007进行了对比。

An approach coupling Monte Carlo automatic modeling(MCAM), Monte Carlo particle transport calculation code MCNP with the self-developed activation code BURNDOT was developed to integrate the functions of neutron transport, activation of materials and decay gamma transport. The approach was applied to the evolutions of the dose of 14 MeV deuterium-tritium(D-T) rotary target chamber. Not only the distributions of three dimensional dose field induced by prompt neutron, γ-ray during the radiation and delayed γ dose variations after a continuous neutron radiation operation over 8 hours were obtained, but also influence of structural materials, cells and nuclide on impact delayed γ dose at varied time after the irradiation was analyzed in detail. The spatial and temporal evolutions of dose of rotary target chamber were obtained, and compared with calculation results of the European activation code FISPACT-2007.