猝发强流多脉冲电子束源物理设计

给出一台脉冲间隔100～1 000 ns、脉冲数2~5个、二极管电压3 MV、引出束流强度2.5 kA的猝发多脉冲电子束源的物理设计及初步调试结果。在设计中，采用感应叠加和阻抗匹配方案获得二极管高电压脉冲；试验中分别采用天鹅绒和大发射面储备式热阴极获得猝发多脉冲电子束。调试结果表明:采用大发射面热阴极可避免阴极等离子体产生，确保二极管在猝发多脉冲状态下稳定运行。初步调试获得大于2.7 MV猝发三脉冲二极管高压，并获得1.6 kA的三脉冲电子束流。

Design of multi-pulsed electron source

A multi-pulsed electron source is introduced, including the design and the first experimental results. The multi-pulsed electron source can generate multi-pulsed intense electron beams with energy of 2 to 3 MeV and beam intensity of 2.5 kA. The pulse interval is adjustable from 100 ns to 1 000 ns without special step. An inductive adder with multi-pulsed driving source is chosen to generate pulsed vacuum diode voltage and both velvet cathode and large-emission-area thermionic dispenser cathode are adopted to generate multi-pulsed intense electron beams. In order to adopt the two different cathodes, two different diodes with the same interface are adopted. The first experimental results indicate that the source runs stably. The multi-pulsed diode voltage is now up to 2.7 MV and the beam intensity is more than 1.6 kA both near the anode hole with Faraday cup and near the exit of the source with B-dot. The experimental results also indicate that using velvet as cathode the cathode plasma is inevitable and beam intensities become much bigger from pulse to pulse; when the largr-emission-area thermionic dispenser cathode is used, there is few cathode plasma and beam intensities are almost the same form pulse to pulse.