在“剑光一号”上搭建了二极管平台, 理论估计了二极管阻值, 进行了平板二极管阻抗和束流分布测量实验。结合法拉第筒阵列测得的束流密度分布、粒子模拟 (PIC)仿真结果对二极管阻抗特性进行了全面的对比分析。结果表明, 二极管工作于弱箍缩状态, 阻抗阻值略低于估计值, 阻抗曲线、法拉第筒波形以及束流箍缩程度三者间存在高度的相关性。当阻抗曲线处在前端(导通前)和末期(崩溃段)时, 束流均处在未箍缩期间, 法拉第筒信号无有效数据; 阻抗曲线处在平区时, 二极管工作平稳, 束流箍缩情况和法拉第筒信号稳定, 阳极边缘处的法拉第筒波形呈现双峰, 与束流箍缩运动情况相符。

A plain high-current diode is fielded on the “Jianguang-I” accelerator preline, and the diode resistance is theoretically estimated. Impedance measurement experiment is conducted, and the experimental results are analyzed combined with the electron beam density gained by a small Faraday cup array and Particle in Cell(PIC) simulation. The results show that there is a high correlation among the impedance value of the diode, the impedance curve, the Faraday cup waveforms and the beam pinching level. When the impedance curve is at the front (where impedance is established) or at the end (impedance collapsing), the beam is in the non-pinching period, the Faraday cup signal has no valid data. When the impedance curve is in the flat area, the diode works well and the beam pinching and Faraday cup signal are stable, and the Faraday cup waveform at the anode edge shows double peaks, which is consistent with the beam pinch motion.