Study on DC Breakdown Characteristics of Polyimide at Cryogenic Temperature

With the rapid development of superconducting technology, the electrical characteristics of insulating materials at cryogenic temperature has become an important factor which influences the operating performance and reliability and has attracted extensive attention. This paper mainly deals with a new test system which is used to produce a vacuum cryogenic environment for studying the DC insulation characteristics of polyimide from cryogenic temperature to room temperature. Meanwhile, as the wrap structure is primarily used in superconductive electrical equipment insulation, the DC breakdown characteristics of single-layer and double-layer polyimide films were studied in this paper.