Effective generation of electron beams in an abnormal discharge with increased photoelectron emission from a cathode

An abnormal discharge is realized in which electron beams with energies in a kiloelectronvolt range are generated at an efficiency of η∼1. The results are explained within the framework of a photoelectron discharge model. A transition to this mechanism is possible due to a significant increase in the power of self-illumination from a large electron beam drift volume. The passage to a discharge with predominant photoemission leads to a decrease in the cathode potential fall region, a drop in the ion current to the cathode, and an increase in the efficiency.