SCIENTIFIC APPLICATIONS & RESEARCH ASSOCIATES, INC. — Department of Defense STTR Phase I: DTRA16A-004

Description

For effective protection against EMP and HPM threats, it is important to understand the physics of the threats, and also to quantify the effects they have on electrical systems. EMP and HPM vulnerability testing requires delivery of high peak power and electric fields to distant targets. The most practical solution to simulate such environments is to develop a modular, optically-isolated MV-antenna array. This proposal presents an inexpensive 100 kV pulse charger and a low-jitter laser system capable of driving gallium arsenide (GaAs) photoconductive semiconductor switch (PCSS)-driven antenna modules. To prevent damaging the PCSS, the primary charge storage capacitor (1 nF) must be pulse charged within <10 us, therefore limiting the voltage seen by the switch. The initial simulations of the proposed pulse charger architecture is capable of delivering 5 J of energy within 7 us with a regulated output voltage of up to 100 kV. The optical parameters required to trigger the PCSSs are 300 uJ of ~840 nm light uniformly distributed on a 3 cm2 area. We have identified the Chromium (Cr) Colquiriite crystal, specifically Cr:LiSAF, supporting optics and electronics to meet the required output wavelength requirement of 840 nm and power necessary to reliably turn-on the GaAs PCSSs.