Criteria for similarity of the processes taking place in vacuum plasma torches with hollow cathodes

Abstract

The article demonstrates that using the vacuum because of its properties as a medium of zero conductivity has enabled to create the construction of hollow cathode plasma torch. An analysis of thermophysical processes inside the cathode channel was carried out. Conditions were determined for the generation of high enthalpy plasma in the cathode channel and the gas-dynamic output of the plasma into the discharge column in the axial direction. A model of the development of the processes of energy input into the cathode channel is considered. General patterns of the working modes are demonstrated, and criteria of similarity for hollow cathode discharges are formulated based on the Knudsen number, the Reynolds criterion and the interconnected electromagnetic parameters.