Research Progress of a Second Harmonic Gyrotron

A scheme of a second harmonic gyrotron operating in CW regime is presented. This tube is designed to provide output power about several tens of watts at 330 GHz. - Whispering-gallery mode is selected as the operating mode. The performance of the candidate TE82 and TE\pmb92 mode is evaluated by nonlinear code. It is confirmed that TE92 mode can suppress the competing modes successfully. The fabricating key components of this tube is presented.