Experimental analysis of an innovative solid-state Marx topology utilizing a boost regulator circuit to generate millisecond pulses with low droop

Summary form only given. High-power solid-state modulators have emerged as reliable, tunable, and cost-effective alternatives to current spark gap and thyratron technologies. The persistent improvement of the power, speed, and availability of solid-state components is generating increased commercial interest in their development. Solid state pulsed systems are optimal for technologies demanding stringent and stable pulse shapes, high repetition rates, ultra-long lifetimes, and performance redundancy. SPICE simulations show that incorporating a boost circuit in parallel with the discharge circuit of a solid-state modulator significantly improves the pulse characteristics. By supplying energy to the pulse during the discharge, the boost circuit can virtually eliminate pulse droop in long pulse applications. The boost circuit is designed to be driven by the same high voltage supply as the central Marx circuit which reduces circuit complexity compared to a parallel buck circuit. A prototype modulator has been designed and built at Stangenes Industries that produces a 6 kV, 19 A pulse that persists for 4 ms with <;1% voltage droop. The pulse repetition rate is 10Hz and the rise and fall time are 400 ns and 800 ns, respectively. The voltage ripple is held at <;1% with a pulse-to-pulse stability of 200 ppm. The function of the prototype modulator parallels the simulation results. While there is no theoretical limit to the pulse length, practicality dictates that there must be adequate recharge time through a conventional high-voltage power supply. The pulse length and power are also limited by the necessity of maintaining a reasonable efficiency. This paper provides those considerations as well as waveforms generated by the prototype modulator. Control circuitry is also briefly discussed.