DC Vacuum Arc Extinction in a Transverse Axisymmetric Magnetic Field

A statistic study of the DC vacuum arc extinction by a vacuum interrupter (VI) with a transverse axisymmetric magnetic field has been carried out at various external circuit parameters. The dependences of the breaking current on the magnetic field and the VI shunting capacity have been found. The executed statistic study has allowed defining the breaking current with the specified probability of failure. The model of evolution,of a non-stationary layer of a negative volumetric charge near the anode is proposed. This model satisfactorily describes the experimental forms of current and voltage in the final high-voltage stage of the vacuum arc extinction. The developed model made it possible to estimate the temperature of anode surface heating in the arc extinction phase.