Vacuum Plasmatrons with Hollow Cathode: Gas-Dynamic Plasma Processes in the Hollow Cathode

It is shown that it is necessary for vacuum plasmatron with hollow cathode to meet the technical requirements to the hollow cathode pipeline to provide not only the necessary kinetic energy of the gas involved in the formation of working parameters in the cavity cathode but also to ensure the stable operation conditions for vacuum plasmatron at large current without the occurrence of high-frequency oscillations in the plasmatron electrical circuit. The pipeline maximum length has been established, guaranteeing the speed of gas at its final section and equals to the speed of sound at the output; the results of mathematical modeling and experimental investigated parameters for developing gas-dynamic processes in hollow cold and hot cathodes of vacuum plasmatrons are presented. The start-up modes ranges for warming up the cavity cathode and continuous discharge output with hollow cathode into working modes with flowing currents up to 10000 A are considered. The occurrence and development of the gradient pressure, density, velocity mass flow rate at heating the cathode and the gradient increase temperature effect of the cathode edge with forming current conductivity active zone in the cylindrical cathode are shown.