High power gyrotron from CPI. The 110-GHz gyrotron is the current world record holder for high frequency power generation. This gyrotron is used in electron cyclotron reso- nance heating(ECRH) by producing extremely high frequencies of microwaves which heat a hydrogen gas-plasma-to very high levels in experimental fusion reactors In the photo, the lower section is the electron gun region that generates extremely high-powered electron beam Shown in the middle section of the gyrotron is an interactive window. The produced microwave power is transformed into a microwave beam that then passes through the high power interaction window. The large upper section is a fully instrumented collector of the"spent"electron beam. Photo courtesy of Communications c 2000 by CRC Press LLCHigh power gyrotron from CPI. The 110-GHz gyrotron is the current world record holder for high frequency power generation. This gyrotron is used in electron cyclotron reso￾nance heating (ECRH) by producing extremely high frequencies of microwaves which heat a hydrogen gas — “plasma” — to very high levels in experimental fusion reactors. In the photo, the lower section is the electron gun region that generates extremely high-powered electron beam. Shown in the middle section of the gyrotron is an interactive window. The produced microwave power is transformed into a microwave beam that then passes through the high power interaction window. The large upper section is a fully instrumented collector of the “spent” electron beam. (Photo courtesy of Communications & Power Industries.) © 2000 by CRC Press LLC