Off-axis emission of electrons by discharge of a low-inductance vacuum spark.

Abstract

The article presents the results of the study of electrons, emitted by the plasma of a low-inductance vacuum spark. It was found that a 50-kA discharge with a 3.4-µs period of current oscillations produces electrons with the energy higher than 100 keV, which leave the discharge plasma in the direction perpendicular to the discharge axis. The electrons have an energy spectrum close to monoenergetic. They appear after the first quarter period of discharge current oscillations and are emitted during about 1 µs. So, the origin of the electrons has no relation to the process of plasma pinching. The time behavior of the electron energy was studied. It gradually diminishes from a value of about 100 keV just after the maximum of the discharge current down to about 10 kV after reversal of the current direction. This phenomenon points out the redistribution of the discharge current, resulting in the disappearance of the magnetic field on the line of sight perpendicular to the discharge axis.