Title :
Demonstration of a high-power long-pulse 140-GHz gyrotron oscillator
Author :
Blank, Monica ; Felch, Kevin ; Borchard, Philipp ; Cahalan, Patrick ; Cauffman, Stephen R. ; Chu, Tak Sum ; Jory, Howard
Author_Institution :
CPI Microwave Power Products Div., Palo Alto, CA, USA
fDate :
6/1/2004 12:00:00 AM
Abstract :
A high-power long-pulse 140-GHz gyrotron oscillator has been designed, constructed, and tested. Key features of the gyrotron include an internal converter to transform the TE28,7,1 operating mode to a Gaussian output beam, a single-stage-depressed collector, and a chemical-vapor-deposition diamond output window. Peak output powers up to 930 kW at 34% efficiency have been demonstrated at 5-ms pulse lengths. Due to power supply limitations, long-pulse operation was not possible for beam currents above 25 A. At 25-A beam current and 500-kW output power, pulse lengths up to 700 s in duration were achieved. The gyrotron has been shipped to the Wendelstein 7-X facility in Greifswald, Germany, where long-pulse demonstrations up to 180s will be carried out at the 930-kW power level.
Keywords :
convertors; cyclotron masers; gyrotrons; millimetre wave oscillators; millimetre wave power amplifiers; 140 GHz; 25 A; 34 percent; 5 ms; 500 kW; 930 kW; Gaussian output beam; Wendelstein 7-X facility; chemical vapor deposition diamond output window; depressed collector; electron-cyclotron-current-drive; electron-cyclotron-resonance-heating; high-power long-pulse gyrotron oscillator; internal converter; millimeter wave; power supply limitations; pulse lengths; single-stage-depressed collector; Cathodes; Chemical vapor deposition; Gyrotrons; Oscillators; Particle beam injection; Particle beams; Power generation; Pulsed power supplies; Structural beams; Testing; Depressed collector; ECCD; ECRH; electron-cyclotron-current-drive; electron-cyclotron-resonance-heating; gyrotron; millimeter wave;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2004.828815