Title :
Recent progress in the development of high frequency gyrotron oscillators
Author :
Kreischer, K.E. ; Spira, S.E. ; Temkin, R.J.
Author_Institution :
Plasma Fusion Center, MIT, Cambridge, MA, USA
Abstract :
Research on the development of high-frequency (>100 GHz) gyrotron oscillators is discussed. As part of a program to develop high-power sources for ECR (electron cyclotron resonance) heating of fusion plasmas, a cylindrical cavity with an interaction length of 6 lambda and diffractive Q of 420 has been used to produce output powers up to 765 kW in the TE/sub 16.2.1/ mode at 148 GHz. This corresponds to an efficiency of 22% based on a 96-kV, 36-A beam. The coupling of the electron beam to different azimuthal rotations of the cavity mode was also observed and found to be consistent with the radial position of the beam in the cavity. Submillimeter sources appropriate for space-based radar systems are also being developed. In recent experiments, the use of a motheye window with high reflectivity at submillimeter wavelengths has resulted in second-harmonic emission at frequencies up to 503 GHz.<>
Keywords :
gyrotrons; microwave oscillators; submillimetre wave devices; 148 GHz; 22 percent; 36 A; 503 GHz; 765 kW; 96 kV; ECR heating; TE/sub 16.2.1/ mode; azimuthal rotations; cavity mode; cylindrical cavity; diffractive Q; electron beam coupling; fusion plasmas; high frequency gyrotron oscillators; motheye window; output powers; second-harmonic emission; space-based radar systems; submillimetre sources; Cyclotrons; Diffraction; Electrons; Frequency; Gyrotrons; Heating; Oscillators; Plasma sources; Power generation; Resonance;
Conference_Titel :
Electron Devices Meeting, 1988. IEDM '88. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
DOI :
10.1109/IEDM.1988.32773
