Dynamics of thermal parameters and erosion of activated thermionic cathode

Temporal variation of the conductive heat flux, temperature field, and specific erosion of thermionic rod cathodes made of thorium doped and pure polycrystalline tungsten have been measured for the first time over a long (20 h) period of arc discharge operation. The laws of dynamics of the thermal state and specific erosion of electrodes have been studied as dependent on the current load, plasma-forming gas (argon) pressure, and cathode material. It is established that the dynamics of integral parameters of the activated electrode is determined by the intensity of dopant evaporation.