Slow cyclotron instability in a high-power backward-wave oscillator

Author

Choyal, Yaduvendra ; Minami, Kazuo ; Granatstein, Victor L.

Author_Institution

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

Volume

32

Issue

6

fYear

2004

Firstpage

2157

Lastpage

2168

Abstract

The linear dispersion relation of a backward-wave oscillator (BWO), derived earlier by the authors, is modified to include effects of RF surface current at the beam-vacuum interface. This modified dispersion relation results in an unstable interaction between the slow cyclotron mode (SCM) and the structure mode in addition to the conventional Cherenkov instability caused by the slow space charge mode. Numerical analysis is then carried out using parameters of a BWO experiment at University of Maryland. Fine structure of the SCM instability is elucidated. The analysis indicates that BWO radiation would not be suppressed near cyclotron absorption in an infinitely long system.

Keywords

Cherenkov radiation; backward wave oscillators; dispersion relations; numerical analysis; slow wave structures; space charge waves; BWO; RF surface current; beam-vacuum interface; conventional Cherenkov instability; cyclotron absorption; fine structure; high-power backward-wave oscillator; linear dispersion relation; numerical analysis; slow cyclotron instability; slow cyclotron mode-structure mode interaction; slow space charge mode; Cyclotrons; Dispersion; Electromagnetic wave absorption; Electron beams; Magnetic analysis; Magnetic fields; Magnetic resonance; Oscillators; Radio frequency; Space charge; Absolute instability; Trivelpiece-Gould modes; backward-wave oscillator (BWO); convective instability; cyclotron absorption; high-power microwave; saddle point; slow electron cyclotron mode instability;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/TPS.2004.835972

Filename

1366507