脉冲硬X射线能谱软化方法数值分析

基于轫致辐射原理，提出了通过轫致辐射靶优化设计软化脉冲硬X射线能谱的方法。采用MCNP程序模拟了复合薄靶和反射靶的输出参数，分析了复合薄靶中转化靶和电子吸收材料厚度对脉冲硬X射线能谱、转换效率以及透射电子份额的影响；给出了反射靶透射和反射X射线能谱、转换效率的差异及其随电子入射角度的变化规律。根据模拟结果分析了两种方法的可行性，并进行了实验验证，为轫致辐射靶的优化设计提供参考。

Numerical Analysis of Spectrum Degradation Methods of Pulsed Hard X-ray

Spectrum degradation methods of pulsed hard X-ray by optimum design of bremsstrahlung convertor were introduced based on bremsstrahlung principal. Output parameters of composite convertor and reflection convertor were simulated by using MCNP code. Influence of convertor thickness on spectrum, conversion efficiency of X-ray and transmission electron quota was analyzed. The difference of spectrum and conversion efficiency between transmission and reflection X-ray of reflection convertor and the change law of these parameters according to electron incidence angle were presented. Experiments of two convertors with different thickness were carried out, and the experimental result is close to simulation result. These methods can be used to degrade spectrum of pulsed hard X-ray.