Comparison of carbon fiber and cesium iodide-coated carbon fiber cathodes

Author

Shiffler, Don A. ; LaCour, Matthew J. ; Sena, Miguel D. ; Mitchell, Michael D. ; Haworth, Michael D. ; Hendricks, Kyle J. ; Spencer, Thomas A.

Author_Institution

Air Force Res. Lab., Directed Energy Directorate, Kirtland, NM, USA

Volume

28

Issue

3

fYear

2000

fDate

6/1/2000 12:00:00 AM

Firstpage

517

Lastpage

522

Abstract

Presents results of an experimental comparison of a bare carbon fiber cathode and the same cathode when coated with cesium iodide salt (CsI). An annular cathode was constructed by arranging carbon fibers in an annular tuft pattern. The cathode was then operated as a bare carbon fiber cathode and in a configuration with a CsI coating. The cathode was tested at electric field strengths ranging from 50 kV/cm to 265 kV/cm at anode-cathode (A-K) gaps of 3.175 cm. The applied voltage had a 1-μs duration and the modulator was operated at up to 1 Hz repetition rate. The system had a low base pressure (<1.0×10^-7 torr). The article reports on results concerning the conditioning of the cathodes, the shot-to-shot reproducibility of the cathodes and the pressure evolution of the diode under 1 Hz operation. We also report on the impedance evolution of each of the diodes

Keywords

caesium compounds; carbon fibres; cathodes; electron field emission; microwave generation; microwave tubes; vacuum microelectronics; 1 Hz; 1 mus; 1E-7 torr; 3.175 cm; C; C fiber cathode; CsI; CsI coating; CsI-C; CsI-coated C fiber cathodes; annular cathode; annular tuft pattern; anode-cathode gaps; applied voltage; carbon fibers; conditioning; diode; electric field strengths; impedance evolution; low base pressure; modulator; pressure evolution; repetition rate; shot-to-shot reproducibility; Carbon dioxide; Cathodes; Coatings; Diodes; Electron beams; Electron tubes; Impedance; Optical fiber testing; Plasmas; Voltage;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.887662

Filename

887662