Electrode phenomena and measurements of the erosion rate in high-current pseudospark switches

For microsecond pulses and peak currents up to 105 kA, the erosion rate, electrode profile, and electrode surface of molybdenum electrodes were investigated. The direction of electrode material transport was verified. The discharge behavior of molybdenum electrodes was studied by streak photography. A contraction of the plasma column occurs at the cathode for peak currents above 20 kA. A bright luminous anode flare appears at a peak current of about 40 kA, correlated with an evident anode melting. A further constriction of the anode flare was observed for currents exceeding 90 kA. Opposite to lower currents, an increase in the weight of the cathode was noticed as well.