Cumulation of a High-Current Electron Beam During a Nanosecond High-Voltage Discharge in a Low-Pressure Diode

Abstract

The results of an experimental investigation of the effect of cumulation of a beam of runaway electrons formed in a high-voltage nanosecond discharge at a reduced air pressure are presented. The optimal conditions of this effect in a discharge gap in a tubular cathode – grounded planar anode geometry were achieved at an air pressure of ≈5 Pa and an interelectrode gap of 2.75 mm. An electron-beam current pulse is recorded with a high time resolution (up to about 80 ps) behind the flat foil anode. It is found out that due to this effect a through hole is formed in a 20 μm-thick aluminum foil after 2–3 discharge pulses. The results obtained suggest that the electron energy in the second part of the beam current pulse is lower than that in its first part.