Studies to improve performance of Maxwell ATLAS rail-gap switches

Summary form only given. This work reports on experimental tests aimed at improving the operation of Maxwell ATLAS rail-gap switches. The present switches are demonstrated to have a decreased maintenance cycle relative to the former, epoxy-body, rail-gap switch. The cause is UV degradation of the polyurethane switch housing. Experimental tests using a UV coating are performed in an effort to extend the maintenance cycle greater than the average 160 discharges. The standard gas used in rail-gap switches is a mixture of (85% Ar/15% SF/sub 6/). The ATLAS switch has a limited flexibility for changing the switch gap. Thus it is highly desirable to extend the operating voltage of a given gap setting by using different gas mixtures. We explored this possibility by performing self-break tests using various gas mixtures, including (90%, Ar/10% O/sub 2/), (95% Ar/5% O/sub 2/), (60% Ar/40% He), (60% Ar/35% He/5% SF/sub 6/) and (80% Ar/15% He/5% SF/sub 6/). It is worth noting that the (90% Ar/10% O/sub 2/) mixture has been used previously to lower the operating voltage in earlier switches. The possibilities of increasing maintenance service cycles and of extending the voltage-operating region with a fixed gap using different gas mixtures are reported.