Development of 50kV air-core transformer for electron gun static power source of 3MeV DC accelerator

A 3 MeV, 10 mA DC Electron Beam Accelerator based on the capacitively coupled parallel-fed voltage multiplier in 6 kg/cm² SF₆ gas environment is under commissioning at Electron Beam Centre, Kharghar, Navi Mumbai. Electron Gun is situated at -3 MV terminal which requires a constant power for its anode and filament. Gun power source has been derived by suitably coupling the ac components present in the HV Multiplier column. An aircore step down transformer rated for 50kV/600V/120kHz floating at 3 MV to extract the required power for electron gun from high voltage column has been developed. The transformer has been operated for 7 kW, 1 MeV of electron beam in 6 kg/cm² nitrogen gas environment. The paper describes briefly about the design aspects and test results. (author)