Design and emission uniformity studies of a 1.5-MW gyrotron electron gun

Author

Anderson, James P. ; Korbly, Stephen E. ; Temkin, Richard J. ; Shapiro, Michael A. ; Felch, K.L. ; Cauffman, S.

Author_Institution

Plasma Sci. & Fusion Center, Massachusetts Inst. of Technol., Cambridge, MA, USA

Volume

30

Issue

6

fYear

2002

fDate

12/1/2002 12:00:00 AM

Firstpage

2117

Lastpage

2123

Abstract

We present the design and initial operation of a 96-kV 40-A magnetron injection gun for a 1.5-MW 110-GHz gyrotron. A critical parameter for the successful application of this electron gun is the uniformity of electron emission. The current-voltage curve of emission, at a series of temperatures, is measured. Analysis indicates that the work function of the emitter is 1.6 eV with a (total) spread of 0.07 ± 0.01 eV. Measurement of the azimuthal emission uniformity with a rotating probe indicates that the work function variation around the azimuth, the global spread, is 0.04 ± 0.02 eV. The spread due to local (microscopic scale) work function variations is then calculated to be 0.06 ± 0.02 eV. Temperature variation can be ruled out as the cause of the observed emission nonuniformity.

Keywords

electron emission; electron guns; gyrotrons; magnetrons; work function; 1.5 MW; 1.6 eV; 110 GHz; 40 A; 96 kV; azimuth; azimuthal emission uniformity; design; electron emission uniformity; emission nonuniformity; emitter; global spread; gyrotron electron gun; initial operation; magnetron injection gun; rotating probe; temperature variation; work function; Cathodes; Current measurement; Electromagnetic heating; Electron emission; Electron tubes; Gyrotrons; Magnetic analysis; Microwave devices; Power industry; Temperature measurement;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/TPS.2002.806639

Filename

1178834