工业X光二极管重复频率实验研究

工业X光二极管型单焦点高重复频率闪光X光机在科学研究、工业检测等领域具有重要应用前景。基于光导开关脉冲驱动源开展了金属阴极工业X光二极管重复频率运行实验, 采用烘烤处理方法研究阴极表面吸附特性对重复频率发射特性的影响；以二极管阻抗模型为理论基础, 通过重复频率实验获得的二极管电压维持时间和阻抗特性分析等离子体扩散过程。研究表明:对于高阻抗结构工业X光二极管, 金属阴极为表面吸附杂质或气体解吸附形成等离子体发射机制, 一次放电后阴极表面对气体的再吸附过程限制了其在高重复频率条件下的电流发射能力, 同时由于阴极等离子体扩散过程变慢使得二极管电压脉宽变长。具有高重复频率电流发射能力的阴极是发展单焦点重复频率X光机的基础。

Research on repetitive rate of industrial X-ray diode

The flash X-ray generator with an industrial X-ray diode would be widely applied in research and industrial detection, which is capable of generating intense x-ray under high repetitive frame. An industrial X-ray diode was driven by the pulsed power supply under 100 Hz to 1 kHz, whose copper cathode was heated to analyze how the surface adsorption affects the electrons emission process. Plasma diffuse processes were investigated simply based on voltage duration and impedance model. The study shows that explosive emission electrons come from gas desorption on copper cathode surface, and the key factor affecting repetitive rate is not diode recovery. Gas absorption velocity between shots is under no more than 1 kHz, so it is a groundwork to develop a novel cathode capable of supplying enough electron beam with high repetitive rate.