Non-arcing commutation in explosive opening switches

The authors examine the commutation performance of the RAP switch in the Air Force Armament Technology Battery Power System. The system stores over 10 MJ at up to 2.5 MA in an inductor. The RAP switch is used to commutate the current into a railgun load. The RAP switch develops several hundred volts before it completely opens and arcs. The authors have developed an analytic description of the nonarcing opening powers and show that it is primarily resistive and that current diffusion plays a central role. Experimental results which validate the theoretical model are also presented. It is shown how the effect can be exploited to achieve higher nonarcing impedance, therefore reducing the destructive effects of arcs on the opening switch