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 1000 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 larger-emission-area thermionic dispenser cathode is used, there is few cathode plasma and beam intensities are almost the same for-m pulse to pulse. (authors)