High-power low-pressure gas discharge switches with internal magnetic field generation

A possible solution to the problem of electrode deterioration in high-power gas discharge switches is the application of magnetic fields in order to magnetically sweep the plasma channel over the switch electrodes. Transverse magnetic field configurations have been investigated in low-pressure switches in order to improve their lifetime and extend their switching capabilities. With spiral type electrodes, arc speeds of over 100 km/s have been measured. Although limited to less than 40 kA due to intense plasma-wall interaction, this configuration is well suited for the investigation of fundamental physics concerning arc movement and plasma-electrode interaction in low-pressure gas discharge devices. In a coaxial electrode configuration, a cumulative lifetime of >1800 C has been achieved, at a peak current of 100 kA and a pulse duration of 28 us.