Specific Features of the I–V Characteristics and High-Efficiency Electron-Beam Generation in a Continuous Open Discharge

Abstract

The main features of a continuous open discharge used to generate electron beams in medium-pressure gases are discussed. I–V characteristics have been investigated, current and energy efficiencies have been measured, and conditions for obtaining a high (comparable with the anode geometric transparency) energy efficiency of beam generation in helium at a pressure of 10–30 Torr and its mixtures with oxygen have been established. Fundamental differences between the investigated and anomalous discharges have been found. In particular, a Z-shaped I–V characteristic has been obtained and attributed to the modification of the role of main electron emission mechanisms with increasing voltage.