为了探索杆箍缩二极管(RPD)在冲击加载下物质低密度区成像应用中的可行性，开展了低电压(≤500 kV)运行条件下RPD箍缩物理特性模拟研究。基于Particle-in-cell(PIC)模拟方法，从二极管加载电压幅值、阴极盘厚度、阴阳电极孔径比等方面开展了二极管模拟，从电子箍缩效率、质子流、电子利用率、电场和磁场分布等角度对箍缩物理过程进行了分析。模拟表明：低电压运行条件下普通结构二极管电流较低，不能为电子提供足够的磁场力从而导致较低的电子箍缩效率；采用组合杆结构，并优化阳极杆到轫致辐射靶区的过渡区设计，是在低电压条件下实现小焦斑、高剂量辐射光源的值得探索的技术途径。

In order to explore the feasibility of low density imaging of rod pinch diode (RPD) under impact loading, a simulation study on physical properties of RPD under low voltage operation (≤500 kV) is carried out. Based on particle-in-cell (PIC) simulation method, a simulation is carried out on amplitude of loading voltage of diode, thickness of cathode plate, aperture ratio of cathode and anode, etc. The physical process of pinch is analyzed according to the angle of electron pinch efficiency, proton flow, electron utilization, electric field and magnetic field distribution. The simulation results show that the current of RPD is low under low voltage operation, and can’t provide enough magnetic force for the electron, resulting in low electron pinch efficiency. It is a technical approach to realize high dose and small focal spot light source under low voltage condition by using composite rod-pinch diode and optimizing design of the transition region of anode rod to bremsstrahlung target region.