DC short-circuit treeing phenomenon and space charge effect in EPR at cryogenic temperature

Short-circuit tree initiation voltage of EPR at cryogenic temperature is much higher than that at room temperature. Space charge measurement was carried out using pulsed electroacoustic method. Injection of negative space charge occurred at room temperature from the cathode, but at cryogenic temperature the injection is very limited. For DC electrical insulation, space charge is less problematic at cryogenic temperature than at room temperature