An electron-beam accelerator, which consists of a primary storage
capacitor system, an air core spiral strip transformer, water Blumlein
line of water dielectric, and a field-emission diode, is described. The
experimental results show that the diode voltage is more than 400 kV,
electron beam current is about 40 kA, and the pulse duration is more than
80 ns. This accelerator is very compact and works stably and reliably.