Effect of magnetic field on the dielectric strength of gaseous cooling media for superconducting applications

The influence of magnetic field on the dielectric strength of cryogenic helium is discussed. The effect of magnetic field that is perpendicular to the electric field, as encountered in high-temperature superconducting (HTS) power cables, on the dielectric aspects was investigated. Experiments measuring the breakdown strength of helium gas with and without the magnetic field were performed, and the results were further analyzed based on the developed models. The experimental results showed no significant effect of the magnetic field on the dielectric strength of gaseous helium.