Magnetic inhibition of insulator flashover

Electrical breakdown across a vacuum/plastic interface in the presence of applied or self‐generated magnetic fields, B?3.5 T, was investigated. The E×B drift of charged particles near the interface in these experiments was away from the insulator surface. The self‐magnetic field effects on a plastic vacuum insulator flashover were examined with inductive loads, particle beam loads, and imploding plasma loads. Average breakdown electric fields of up to 38 MV/m were observed. Power densities of 100 TW/m2 were passed through acrylic‐vacuum interfaces. The flashover electric fields were improved over the B = 0 fields from previous experiments by factors of 7.1, 5.0, and 1.8 for the −45°, 0°, and +45° insulators, respectively.