Theoretical study of magnetic and shock wave pressure effects on the rail gap switch surface used at the Amirkabir Mather type plasma focus facility

Whereas high voltage and current create a rough environment for switch electrodes in pulse power technology, the switch requires the most maintenance or replacement after a short time. In this paper we investigate the effect of magnetic and shock pressure created by high power electric arc between a rail gap switch with Cu electrodes at a new Mather type plasma focus facility (16 kV, 110 nH, 36 muf). As studied by others, the shock pressure is some order of magnitude higher than the magnetic pressure after electric arc generation. We calculated the magnetic pressure, electric arc radius, time dependent arc velocity, and also time dependent shock pressure created by an oscillating current discharge applied across the rail gap electrodes surface. Calculations are made by MATLAB and the results show that the shock wave pressure induced after the electric arc has a serious destructive effect on our switch surface.