New studies of explosively formed fuse opening switches

Summary form only given, as follows. Explosively formed fuse opening switches have been developed for applications in high-energy explosive pulsed power systems. An explosive charge forces the electrical conductor across a Teflon(R) forming die. The switch thus combines the action of the explosively driven mechanical deformation and electrical fusing of the conductor. Such switches have operated at power levels up to 6 TW in systems with 18 MJ stored energy, allowing currents of up to 20 MA to be delivered to 15 nH loads on time scales of a few /spl mu/s. These devices were developed to power plasma or solid cylindrical implosion loads. In recent tests we have explored a wider range of parameter space than previously accessed, allowing the consideration of more compact designs with more flexible applications. The combined effects of explosive power and electrical conduction through the explosive products have been studied, and this leads to the choice of better explosives. Experiments conducted in small planar assemblies will be described, and the implications for small diameter cylindrical assemblies. Switches opening on a 1 to 10 /spl mu/s time scale with resistances starting at 50 /spl mu//spl Omega/ and increasing to perhaps 1 /spl Omega/ now seem possible to construct, using explosive charges as small as a few pounds: in initial experiments, using cylindrical switches of 10 cm diameter and 43 cm length, the switches interrupted currents of approximately 3 MA producing 200 kV.