对4 MeV闪光X光机的轫致辐射靶参数进行了设计和模拟计算。利用蒙特卡罗程序，计算得到当轫致辐射靶的有效钽靶材厚度约为0.6 mm时，靶正前方1 m处产生的单脉冲X光的照射量值最大，可以达到约2.86×10^－3 C/kg，满足4 MeV闪光X光机对其单脉冲X光的设计要求。对不同能量下的单脉冲电子束加载在轫致辐射靶上的能量沉积密度进行了计算和比较，分析研究了不同结构下的靶破坏，结果表明：轫致辐射靶采用叠靶结构的钽靶能够满足4 MeV闪光机的实验需求。

Bremsstrahlung converter target is one of the key factors for flash X-ray machine. The bremsstrahlung radiation process in which the electron beam impinges on the target is simulated utilizing the Monte Carlo method, by which the influence of the effective target thickness on the exposure is analyzed, the optimal target thickness and the exposure are also obtained for the 4 MeV flash X-ray machine. The damages of target impacted by the electron beam are compared and discussed for various electron energy deposit density from different sources, such as 12 MeV LIA, Dragon accelerators and 4 MeV flash X-ray machine. The results show that the tantalum distributed target may be the satisfactory solution for the bremsstrahlung target of 4 MeV flash X-ray machine.