中文摘要：

采用UNIPIC程序模拟Rod-pinch二极管（RPD）的工作过程，重点研究阳极等离子体和二极管结构参数对电子束箍缩的影响。模拟结果表明，在不考虑阳极离子流作用情况下，RPD无法在较低电压下（〈2MV）实现箍缩；当阳极离子流达到一定值后，进一步增加阳极表面发射离子流密度对二极管总电流和阳极杆尖端电流密度影响很小；阴极不同表面发射电子束的箍缩效果不同，各表面同时发射电子时，后表面发射的电子束箍缩效果最好，其次是中间表面，前表面最差；增大阴极厚度不能显著缩短电子束实现箍缩的时间。给出了阳极杆伸出阴极平面距离和阴阳极半径比等参数的选取范围，对模拟计算与实验结果间的偏差作出了解释。

英文摘要：

The UNIPIC code is used to simulate working process of a rod-pinch diode. The influences of anode plasmas and diode structural parameters on electron pinching are investigated. The electron beams don＇t pinch to the rod tip at 1-2 MV without the ion effect. When the ions emitted from the anode surface reach a current of certain value, further increase of the ion current does not have a significant influence on the diode total current and the current density at the rod tip. With all the three surfaces of the cathode emitting electrons, the pinching quality of the electron beam emitted from the upstream surface is the best of all surfaces. Increasing the cathode length does not have an obvious effect in accelerating the process to achieve strong pinching. Influence of the distance from the anode tip to the cathode surface is analyzed, too. The differences between numerical simulations and experimental results are explained.