Generation of high-energy electrons in a transverse slot-cathode nanosecond discharge at working gas medium pressures

Experimental data for the electrical and optical characteristics of a transverse slot-cathode nanosecond discharge are reported. The discharge is initiated in He at a discharge current of 1–500 A and a working gas pressure in a discharge chamber ranging from 10² to 10⁴ Pa. It is shown that the cathode current density is much (several orders of magnitude) higher than the total current density of an equivalent abnormal discharge. The electrical characteristics of an open discharge and a discharge confined by dielectric walls are found to differ considerably. Electrons passing through the cathode fall region acquire a high energy (on the order of 1 keV) under the given conditions. The fast electron relaxation conditions correlate with the initiation and evolution of the discharge. A pattern of the discharge evolution is derived from experimental data. A way of estimating the coefficient of electron emission from the cathode plasma is suggested.