Title :
Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz
Author :
Hornstein, Melissa K. ; Bajaj, Vikram S. ; Griffin, Robert G. ; Temkin, Richard J.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., MIT, Cambridge, MA
Abstract :
The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE2,3,1 mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents
Keywords :
electron guns; gyrotrons; microwave oscillators; millimetre wave generation; submillimetre wave generation; 12 W; 233 GHz; 3.5 kV; 50 mA; CW gyrotron oscillator; EGUN electron optics code; cooling system; electron gun; millimeter-wave source; terahertz radiation; Cooling; Electricity supply industry; Electron optics; Gyrotrons; Oscillators; Power generation; Predictive models; Radio frequency; Tellurium; Voltage; Compact; dynamic nuclear polarization (DNP); gyrotron oscillator; low voltage; nuclear magnetic resonance (NMR); portable; terahertz;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2006.889295