Development of 70kV, 22A DC power supply for High Power RF and microwave tubes

Abstract

Our institute (IPR) is involved in the development of High Power RF and Microwave sources for various fusion related heating and current drive applications. All the high power RF and microwave tubes e.g. Klystron, Gyrotron tetrode etc need a high voltage DC power supply to deliver the required high power with necessary protections. To cater to the initial testing and commissioning requirements, the development of 70kV, 22A power supply is initiated. The supply ratings are chosen to meet general tube requirements i.e. Klystron, Gyrotron and Tetrode used in RF group. The supply would be a part of test facility, rather than a regular supply for use in an experiment. Hence some ripple and regulation requirements are relaxed to optimize the cost. However all protections including crowbar protection are accommodated. This supply when ready enables continuous full power testing of TH 2103D Klystrons, GLGD-82.6/0.2 Gyrotron and short time (3Sec-"ON", 120Sec-"OFF") full power testing of 1.5MW Tetrode. This paper presents analysis of requirements of various tubes, power supply rating optimization, topology selection, protection requirements and other facilities required. Remote monitoring through DAC and remote control requirement from various locations, are highlighted. Present status of development is mentioned.