Starting energy and current for a large diameter finite length backward wave oscillator operated at the fundamental mode

Author

Minami, K. ; Ogura, K. ; Aiba, Y. ; Amin, M.R. ; Zheng, X.D. ; Watanabe, T. ; Carmel, Y. ; Destler, W.W. ; Granatstein, V.L.

Author_Institution

Graduate Sch. of Sci. & Technol., Niigata Univ., Japan

Volume

23

Issue

2

fYear

1995

fDate

4/1/1995 12:00:00 AM

Firstpage

124

Lastpage

132

Abstract

We study the starting conditions for a large diameter (diameter/wavelength=4.8) finite length backward wave oscillator designed for 24-GHz operation at the fundamental TM₀₁ mode. This geometry is very promising for high power handling capability. We analyze two separate threshold conditions. First, finite length effects give rise to a threshold in electron beam energy below which oscillations cannot be sustained at any beam current. The second is the more familiar current threshold known as a start current. It is also found that the growth rate for the fundamental mode can be much larger than those of other higher order modes thus leading to coherent operation of large diameter sources free from mode competition

Keywords

backward wave oscillators; dispersion (wave); electromagnetic wave propagation; electron beams; microwave generation; microwave oscillators; numerical analysis; slow wave structures; starting; 24 GHz; TM₀₁ mode; backward wave oscillator; dispersion curves; electron beam energy; finite length; fundamental mode; higher order modes; large diameter; linear analysis; slow wave structure; start current; starting energy; threshold conditions; Electromagnetic heating; Electron beams; High power microwave generation; Magnetic confinement; Microwave devices; Microwave generation; Microwave oscillators; Plasma applications; Plasma confinement; Radio frequency;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.376576

Filename

376576