Anode erosion of a high-current multigap vacuum triggered switch

The paper studies discharge plasma interaction with anode rods of a six-gap vacuum switch resulting in surface melting of copper anode rods and metal droplet formation from electrode material. Using high-speed photography, anode spots formation was recorded and spot dimensions were determined at various discharge currents from similar to 30 kA up to similar to 100 kA. There is presented a one-dimensional nonstationary model of surface anode melting and droplet formation in an anode spot of vacuum arc. Observations of erosion traces at anodes of operative multigap vacuum switches and high-speed photos of discharge in model switches show, that the model of melting and droplet formation by ponderomotive action of discharge current is correct.