High-power coaxial ubitron oscillator: theory and design

Author

Balkcum, A.J. ; McDermott, D.B. ; Phillips, R.M. ; Luhmann, N.C., Jr.

Author_Institution

Dept. of Appl. Sci., California Univ., Davis, CA, USA

Volume

26

Issue

3

fYear

1998

fDate

6/1/1998 12:00:00 AM

Firstpage

548

Lastpage

555

Abstract

The theory and design of a high-power coaxial ubitron oscillator is discussed. The device utilizes a high-current annular electron beam interacting with the radio frequency (RF) breakdown-resistant TE₀₁ mode in a coaxial cavity. Stable and laminar flow of the electrons is achieved without a confining axial field by using periodic permanent magnets to form the wiggler. A linear theory is derived for the cavity´s start-oscillation condition using a Vlasov analysis and a nonlinear simulation code is described. Agreement is good between the linear theory, nonlinear code, and the 2-1/2-dimensional particle-in-cell code, MAGIC. A 1-GW, S-band oscillator design with 21% efficiency is presented. It was found that the interaction efficiency in the cavity could be increased to 46% using the technique of axial mode profiling

Keywords

Vlasov equation; free electron lasers; microwave oscillators; microwave tubes; wigglers; 1 GW; 2-1/2-dimensional particle-in-cell code; MAGIC; S-band oscillator; Vlasov analysis; axial mode profiling; coaxial cavity; electron laminar flow; high-current annular electron beam; high-power coaxial ubitron oscillator; linear theory; nonlinear code; nonlinear simulation code; periodic permanent magnets; radio frequency breakdown-resistant TE₀₁ mode; start-oscillation condition; wiggler; Coaxial components; Electron beams; Free electron lasers; Laser radar; Magnetic circuits; Microwave oscillators; Permanent magnets; Radio frequency; Tellurium; Undulators;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.700790

Filename

700790