All-Solid-State Pulsed Drivers for Powering Plasma-Discharge-Based IR Sources

The overall objective of this effort is to develop all-solid-state pulsed driver technology to efficiency power plasma discharge sources used in IR countermeasures. The driver technology to be developed is based on high pulse rate Insulated Gate, Bipolar Transistors coupled with nonlinear magnetic pulse compression and new fractional-turn output transformer technology developed at SRL. The IGBTs act as a primary commutator and are used to switch the I joule of energy stored at 500 VDC in the primary energy storage capacitors to form 5 usec pulses. Two stages of nonlinear magnetic pulse compression and a fractional-turn output transformer are then employed to compress these pulses to the 20 kV/80 nsec pulses required to charge the peaking capacitors at the plasma discharge load. Circuitry will also be installed to increase the efficiency of coupling electrical energy to the rapidly varying load impedance represented by the plasma discharge. The all-solid-state driver will be designed to operate continuously at repetition rates up to 10,000 pulses per second and to have an operating lifetime of greater than 100 billion shots. In Phase I, Science Research Laboratory (SRL) will make the necessary modifications required to increase the pulse rate of an existing SCR-commutated copper vapor laser driver to 10,000 pps. These modifications will include replacement of the SCRs with IGBTs and upgrading the pulse compression modules, the thermal control systems and the driver trigger system. This modified driver will then be tested into a load circuit which simulates time-varying plasma discharge loads. The driver will be tested to full performance specifications and any performance deficiencies will be corrected. Phase I will culminate in the final engineering design of a prototype all-solid-state driver which will be fabricated and tested at SRL and then delivered to a selected Navy site in Phase II.