Integrated system of a mini-marx generator charged by a cockcroft-walton voltage multiplier

Abstract

A Marx generator generates a high-voltage pulse by charging lots of capacitors in parallel, then suddenly connecting them in series. In principles, a comparatively lower voltage DC power supply can be used for the charging to achieve the desired high voltage. However, a moderate DC high-voltage power supply is still quite expensive and bulky but not in full-time charging. In this work, a mini-Marx generator powered by a Cockcroft-Walton (CW) voltage multiplier has been proposed to form a more efficient but affordable choice of pulsed high-voltage power sources. For generating a high voltage in a range of 70-100 kV, the mini-Marx generator consists of 8 stages. Therefore, a CW multiplier operating up to 10-15 kV is required. For demonstration, a 22-stage CW multiplier with an AC supply voltage of 220V at 60 Hz is chosen so that it can be driven by household electricity to generate a DC voltage of over 13 kV to charge the mini-Marx generator. Numerical simulations using PSpice have been performed for validating the concept. A prototype is developed. After setting a suitable time-controlled switch for releasing CW multiplier and a trigger for the spark gaps of the mini-Marx generator, the preliminary simulation results predicting a pulsed open-circuit voltage up to 85 kV from the mini-Marx generator can be achieved while being charged by the CW generator operating at 11 kV. Detailed simulation and experimental results will be presented.