重复频率高功率微波加速器X射线屏蔽的估算（英文）

X-ray shielding estimations for rep-rate high power microwave accelerators

高功率微波的研究正在向高重复频率发展,目前已运行每年百万炮次或以上的水平,由此导致的电子束轫致辐射产生的X射线剂量已不可忽视,为了人员安全必须采取屏蔽措施。采用BEAMnrc程序,用蒙特卡罗方法仿真了环状束高功率微波源收集极的射线产生情况,典型输入束流参数为电压1 MV,电流10kA,脉宽100ns,重复频率100Hz。仿真结果给出了X射线的谱分布和空间分布。据此估算了屏蔽X射线所需的墙壁衰减量。同时估算了X射线的天空散射因素以及房顶所需的衰减量。

High power microwave research is moving into the high rep-rate regime and it will be common that an electron beam accelerator operates more than a million shots per year.As a result,accumulated bremsstrahlung X-ray produced by the electron beam collector is no longer negligible,and shielding is necessary for personnel safety.By using the BEAMnrc Monte-Carlo code,a typical collector for a ring beam usually used in HPM tube is simulated,which has beam voltage 1 MV,beam current 10 kA,pulse duration 100 ns and reprate 100 Hz.The results show the spectrum and spatial distribution of the X-ray generated at the collector.The attenuation factor of the X-ray is estimated from the simulation.The estimation of the skyshine radiation is also considered for the roof of the building.