Design of the 250 KV thermionic dispenser cathode diode

High brightness electron beam is one of fundamental technique in high current electron accelerator. The thermionic dispenser cathode can provide greater reproducibility, longer pulse lengths and lower emittance beam than field emitting cathode. Here we introduce the vacuum diode design which can produce a long duration pulse with 3/spl mu/s flat-top, 300 amperes' electron beam at a cathode test stand.