The influence of magnetic fields on dielectric surface flashover

The influence of low-amplitude magnetic fields, in a variety of configurations, on pulsed dielectric surface flashover was investigated. These variations included DC magnetic fields, pulsed magnetic fields simulating conditions for magnetic self-insulation, and different environments, geometries, dielectric materials, and orientations of the magnetic field. For field amplitudes of 0.3 T, typically a doubling of the flashover voltage is observed if the E×B drift is away from the surface. For flashover in vacuum, it is sufficient to place permanent magnets in the cathode vicinity to increase the flashover voltage. The observations are consistent with the saturated surface secondary avalanche model and electron-induced gas desorption. The pulse shape of light emission during the prebreakdown phase depends on the orientation and amplitude of the magnetic field and shows that electron trajectories above the surface are altered by magnetic fields