The Design Of Megawatt Gyrotrons For The Compact Ignition Tokamak

A 1 MW, 280 GHz gyrotron oscillator suitable for ECR heating of the Compact Ignition Tokamak (CIT) is presently being designed. The design is based on successful features of our present experiment, which has generated powers up to 765 kW in the TE16,2,1 mode at 148 GHz. In the 280 GHz gyrotron, an 80 kV, 50 A annular beam will interact with a high order whispering gallery mode. Parametric studies indicate that a cavity with a diameter of at least 20A is required to keep wall losses low. Detailed studies of the electron gun and 12 T magnet indicate both are feasible. Initial experiments are planned for late next year.