Distributed Capacitances in HV Multiplier Circuits

HV multipliers are employed for generating high voltage DC output from high frequency AC source. Cockroft Walton Voltage Multiplier (CWVM) is one such cascade multiplier prominently used in DC accelerators. The CWVM is cascade of voltage doubler with output voltage of 2 NV, where N is the number of stages in the cascade network and V is input voltage. However, the multiplication factor practically achieved is lesser than N owing to distributed capacitance in the multiplier circuit. 1 MeV DC accelerator at EBC, Kharghar, is based on symmetrical CWVM driven by 10 kHz high voltage power supply. The multiplier consists of stage capacitor bank, rectifiers for rectification, protective components, and shielding guards. It is housed in a grounded tank in 6 kg/cm2 N2 environment. Distributed capacitances in CWVM of 1 MeV DC accelerator are analyzed and simulated to study the effect on the performance of multiplier circuit.