Electrical breakdown of vacuum insulation at cryogenic temperature

A breakdown experiment on vacuum insulation for the development of cryocable and other cryogenic electrical apparatus was performed. The influence of conditioning, pressure, gap spacing, electrode material, and voltage waveform on the breakdown voltage of vacuum insulation was measured at room temperature and at cryogenic temperature. The results indicate that cooling the high-voltage sphere electrode enhances the breakdown strength of vacuum insulation, and, in general, almost all effects of electrical breakdown of vacuum insulation at room temperature are reproduced at cryogenic temperature at somewhat higher voltage. From the point of view of microparticle-initiated breakdown, the ratio of low-temperature to room-temperature breakdown voltages is discussed