Calculation Method of a Multichannel Hollow Thermal Cathode

A calculation method for a multirod (multichannel) hollow cathode has been proposed. This method is based on solving a system of equations written with allowance for the specific features of a real multirod cathode design. This system includes emission and thermal conductivity equations, energy balances on the cathode surface and at the cathode–plasma interface, the Langmuir and McCone equations, and a number of equations a describing gas flow in the cathode channels. The developed calculation method makes it possible to determine the key operating parameters of the cathode and the cathode region (temperature, midsection-area utilization factor, number of active wires, erosion, current density, electron current fraction, cathode potential drop, ion concentration, electric field strength, etc.) for specified geometry and operating conditions.