强流四脉冲电子束源实验研究

 为了进行强流多电子束源研究，对现有2MeV LIA 注入器进行了四脉冲改造，二极管脉冲电压约500kV。实验研究了天鹅绒阴极在四脉冲条件下的发射能力、传导电流负载效应以及阴极等离子体运动对阴极电子发射和束能量的影响。利用空间电荷限制流模型推算出阴极等离子体膨胀速率在1 ~4cm/μs之间。

Experiment on 4-pulsed intense electron beam source

A four pulsed voltage system (FPVS) has been built based on a 2MeV linear induction accelerator (LIA) injector. With the FPVS, some research on the multi-pulsed vacuum diode was taken. The pulse duration is 100ns and pulse to pulse duration is less than 500ns. The pulsed diode voltages are around 500kV. In this paper, the work on multi-pulse emitting characteristics of velvet cathode is introduced. The CCD photos of emitting cathode indicate that the velvet can't emit electrons uniformly under multi-pulse condition. At the same time, the effects of beam load and cathode plasma to multi-pulse emitting and beam to beam electron energy dispersion are also discussed. The experimental results indicate that the cathode plasma can reduce the effective distance between cathode and anode of diode. With the space charge limited mode, the explosion velocity of cathode plasma is 1～4cm/μs.