170 GHz, 2 MW, CW coaxial cavity gyrotron - experimental verification of the design

For a first industrial prototype of a 2 MW, CW, 170 GHz coaxial cavity gyrotron which is now under fabrication, the design of critical components has been verified experimentally with a short pulse (/spl sim/ few ms) coaxial gyrotron. This tube utilizes the same cavity and same quasi-optical (q.o.) RF-output system as designed for the industrial prototype and a very similar electron gun. The performance of the electron gun and beam has been found to be in agreement with the design. Concerning the microwave generation some discrepancy occurred between theory and experiment. In particular, the excited mode spectrum is more dense than expected. The measured pattern of the RF output beam was found to be in agreement with numerical simulations.