Electron energy distribution in a discharge with a vaporizing hollow cathode

A multigrid electrostatic analyzer is used to obtain the longitudinal energy distribution of the electrons in a discharge with a hollow cathode that vaporizes into a vacuum at discharge currents of $0.5$–$5$ A. Some features of the formation of the distribution function at high energy are clarified. It is found that, depending on the discharge current, there are two forms of electron spectra: with and without a group of electrons at energies on the order of the energy acquired in the cathode potential fall. The influence of the discharge current and the heating of the working material on the high energy part of the electron spectrum, which also consists of two groups of electrons that leave the cathode, is examined. The first group originated in electrons that come from deep in the hollow cathode and the second, in those that come from the end of the cathode.