On temperature dependence of electric strengths of polar polymeric films in low-temperature region

This paper describes the electrical breakdown of polar polymers especially in the cryogenic temperature region. The tests were made with newly developed specimens for the breakdown measurement at cryogenic temperature. The temperature dependence of electric strengths of polar polymeric films in the cryogenic temperature region is quite different from that reported previously with recessed specimens. The new results are inherent to the film. From the dependence of electric strength on the rise rate of applied field and prestressing, it is clear that the electrical breakdown of polar polymers at cryogenic temperature is affected by the space charge effect