Initiation of internal discharges in a liquid-nitrogen-filled cavity

Discharge initiation phenomena in a liquid-nitrogen-filled cavity were investigated using “a.c. impulse” voltage. It was found that the discharge magnitude in the beginning half cycle of the voltage is generally different from that in the next half cycle time. This phenomenon is discussed in terms of discharge processes and the quantity of discharge-formed bubbles. Overvoltage characteristic of the discharge magnitude was also found in a liquid-nitrogen-filled cavity as in a gaseous-nitrogen-filled cavity.