A Mini-Marx Generator Powered by a Cockcroft-Walton Voltage Multiplier for a Compact X-ray Source

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 with the mini-Marx generator consisting of 8 stages, a CW multiplier operating up to 10-15 kV is required. A 22-stage CW multiplier with an AC supply voltage of 220 V 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. For demonstration, a prototype of the 22-stage CW powered 4-stage mini-Marx has been tested with an AC voltage of 110 V at 60 Hz. The CW generator can reach 6 kV to power the mini-Marx, consistent with the PSpice modeling.