Diffuse vacuum arc discharge with heated cathode made of mixture of ceramic and metal powders

Abstract

The paper present results of an experimental study of a plasma flow parameters generated by a vacuum arc discharge with heated cathode made of mixture of ceramic and metal powders. The discharge existed in a diffuse mode of cathode current attachment. The diffuse mode was characterized by relatively low values of cathode current density (10–100 A/cm 2 ), absence of significant voltage oscillations and stable glow of plasma formation. The data on mean charge of the arc plasma flux, ion energies and ion composition measured by time-of-flight mass spectroscopy method were obtained. It was shown that chromium is a main source of the plasma forming medium when cerium dioxide is a main source of electrons of thermionic emission. Obtained results can be useful in designing of stable plasma sources of multi-component condensed substances for wide range of applications from deposition of composite coatings to plasma mass separation.