The influence of magnetic fields on dielectric surface flashover

The effect of magnetic fields on dielectric surface flashover was investigated using two experimental setups, one with DC magnetic fields and the other with pulsed magnetic fields produced by currents of up to 175 kA. The observed insulation effects depend on the dielectric material, ambient gas pressure, surface roughness, and the presence of background plasma. It is sufficient to place the magnetic field in the vicinity of the cathode region only. For practical applications, small low-cost NdFe permanent magnets can be used, even for plasma background conditions with an electron density of 10⁴ cm^-3. The flashover voltage retains the characteristic dependence proportional to the square root of the gap distance with and without the applied magnetic field for DC magnetic field experiments