High voltage pulses for high impedance loads using explosive formed fuses

Explosive formed fuses (EFF's) use conducting elements that are deformed by explosive pressure (typically, against dielectric dies), This causes the f use geometry to change, so that the conducting element cross section decrea ses, This enables a higher ratio of current conduction to current interrupt time than for normal fuses, and it enables more control of when current in terruption occurs. In combination,vith a suitable output closing switch, EF F's can be used to obtain several hundred kilovolt voltage pulses from indu ctive stores to drive several ohm loads, With proper choices of inductive s tore, EFF geometry and material, and output closing switch features, such a voltage pulse can be approximately flat topped for microsecond duration an d have a small fraction of microsecond risetime, We present theoretical ana lysis and circuit simulations which illustrate this, using scaled empirical EFF parameters for inductive stores in the I weber flux, several hundred n anohenry range. The circuit simulations were done using MicroCap-IV, with u ser defined elements. These simulations were done with static inductive sto res and with explosive magnetic flux compression generators driving inducti ve stores.