Analysis of transients in high voltage multipliers

Different forms of Cockcroft-Walton multipliers are widely used to generate very high voltages in the range of millions of Volts. In many applications, high voltage multipliers are insulated by pressurized gas, to realize compact systems. These systems are often stressed to high operating electric fields and suffer frequent discharges especially during high voltage conditioning phase. During high voltage discharges, transient voltages appear in the system creating higher stresses than normal operation in components. Parasitic capacitance between the high voltage system and ground can significantly affect transients in the system. In this paper, a model for analyzing transients in series coupled high voltage multiplier is presented. Typical transient voltage levels in stage inductors and capacitors are discussed. Experimental results with 1 MV, 100 mA symmetrical Cockcroft-Walton multiplier is presented to corroborate predictions from theoretical model.