Protection and control of accelerator microwave sources using a high power IGBT switch

The control and protection of high power electron tubes has been a serious problem throughout the history of power electronics. This paper briefly covers the history of approaches used to meet these needs and discusses a modern solution which has uses in fusion research, accelerator, and commercial applications. The paper describes the design, development and performance history of a family of high voltage IGBT switches used for the control and protection of megawatt level gyrotrons in the JT60U facility. The switch systems described have been in use for several years. The demonstrated long, {over 20,000 system hours, (over 2times10⁶ device hours)} life shows the inherent reliability of a well designed, properly operated HV DC IGBT switch system. This device has many other uses in modern high power electronic systems. In the application described, the switch carries current of the order of 100 amperes DC at 100 kV DC