Dependences of the thermophysical parameters of activated thermal-emission cathodes on the current in a stable arc discharge

The influence of electrical current (in the range 20–150 A) on the thermophysical characteristics of activated thermal cathodes (W + 2% ThO$_2$) in a freely glowing low-pressure argon arc is investigated. For the first time, the dependences of key cathode parameters, such as the heat flux at the electrode, the voltage equivalent of the heat, the specific erosion, and the distributions of the temperature and work function over the extension length of the cathode from the holder, are obtained. A nonmonotonic dependence of the specific erosion on the electrical current with a minimal level at 50–60 A is noted.