High explosive driven closing switches

Two types of high explosive driven closing switch have been developed for crowbar in electromagnetic railguns or other intense current operating devices. The switch geometry configurations are cylindrical or strip. The explosive forming technique was employed to design the switches in which an aluminum impacter driven by a special explosive assembly areal synchronistically hits and cuts the insulator, then is embedded into the slot of another electrode to form a secure contact. The measurements show that their puncture voltage >30 kV, inductance (including transmission line) <50 nH, peak current >400 kA, contact resistance much less than 0.1 mΩ, and the acting time about 15 μsec. The 1D and 2D numerical calculations were carried out to simulate the detonation, impact and deformation process in the switches. An empirical model to describe the switch resistance time-dependence is proposed