激光聚变实验装置屏蔽性能模拟计算

Shielding performance calculation of laser fusion experimental facility

主要采用了蒙特卡罗方法对激光聚变实验装置外表面的中子和光子能谱及剂量进行模拟与分析,引入了MCAM软件绘制激光聚变实验装置的三维模型图,并自动转化为MCNP的输入文件,进行了靶室屏蔽性能的蒙卡模拟,从辐射防护的角度为屏蔽系统的建立、人员的辐射防护以及靶室材料的选择提供理论依据。通过模拟结果得出,CLAM钢作为靶室材料时,其屏蔽中子产生的瞬发光子剂量,在非孔道处是铝合金的1/2左右,40cm厚的混凝土屏蔽层对中子和光子起到了很好的屏蔽作用,均降低了一个数量级,另外在孔道处的中子和光子剂量,加了混凝土的情况反而比裸靶室时高10%左右,建议对靶室孔道外部考虑额外的防护。

This paper utilizes MCNP method together with the MCAM software(Monte-Carlo Automatic Modeling)to simulate the shielding performance of the laser fusion experimental facility's target chamber,in the meanwhile,provides theoretical foundation for the establishment of the shielding system,radiation protection of personnel as well as the selection of the target chamber from radiation protection perspective.The simulation results show that the instantaneous gamma dose in the non-channel area is reduced by 50% when CLAM steel(China Low Activity Martensitic Steel)was applied as the chamber material comparing to the aluminum alloy.In addition,the neutron and gamma dose are decreased one level by using the heavy concrete with a thickness of 40cm(aluminum alloy as the chamber target).It is worth mentioning that the neutron and gamma dose in the channel area is 10%larger than the bared target,so extra protection should be considered outside the hole.