Effect of power reflection on the operation of a low-Q 8 GHz gyrotron

Author

Muggli, P. ; Tran, M.Q. ; Tran, T.M. ; Mathews, H.G. ; Agosti, G. ; Alberti, S. ; Perrenoud, A.

Author_Institution

Centre de Recherches en Phys. des Plasmas, Ecole Polytech. Federale de Lausanne, Switzerland

Volume

38

Issue

9

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

1345

Lastpage

1351

Abstract

The operating characteristics of a low-Q (Q_cav=225), 8-GHz gyrotron oscillator operating in the TE₀₁₁^O mode and submitted to various mismatched loads are reported. Under matched conditions, output power up to 310 kW (η=35%) and maximum efficiency up to 43% were measured. In general, power reflection from loads with different phases and amplitudes leads to an output power decrease. Excessive reflections cause mode switching (TE₀₁₁^O to TE₀₁₂ ^O) or even arcing inside the tube. The effect of power reflection is seen to increase rapidly with current and output power. Nevertheless, as predicted by calculations, the maximum output power is not reached under matched conditions but with a specific nonzero value of the complex reflection coefficient

Keywords

gyrotrons; microwave oscillators; 310 kW; 35 to 43 percent; 8 GHz; TE₀₁₁^O mode; arcing; complex reflection coefficient; effect of power reflection; gyrotron oscillator; low Q gyrotron; matched conditions; maximum efficiency; maximum output power; mismatched loads; mode switching; operating characteristics; operation; output power decrease; power reflection from loads; Frequency; Gyrotrons; Impedance matching; Optical reflection; Oscillators; Plasmas; Power generation; Power measurement; Resonance; Tellurium;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.58663

Filename

58663