ELECTRICAL PERFORMANCE OF EXPLOSIVE-DRIVEN SWITCHES FOR SLAPPER DETONATOR APPLICATIONS

Time dependent resistance measurements were performed on fast, high cu rrent electrical switches proposed for use in slapper detonators. The switches, consisting of a copper-polymer-copper laminate, are designed to conduct electrically after being impacted by an explosive-driven c opper flyer plate. The polymer film used in our experiments was Kapton (polypyromellitimide) and was expected to exhibit shock induced condu ction at pressures of 9 GPa and above. While it is believed that shock pressures in the vicinity of 9 GPa were achieved in the switches, no significant shock conduction effect was observed. This was corroborate d by observing identical electrical behaviour for switches based on Te flon (polytetrafluoroethylene) film, which is known to possess good in sulating properties even under strong shocks. However, in spite of the lack of evidence of significant shock induced conduction in the Kapto n based switch, its operation is satisfactory. The average switch clos ure resistance at practical voltage and current levels was found to be of the order of 0.15 Omega, attained within a closure time of 10 ns t o 20 ns. Also, the electrical characteristic of the switch performance was largely independent of the supply voltage, when a low impedance v oltage source was used, though the closure resistance values displayed a large scatter with standard deviation of the order of 0.1 Omega.