Efficiency enhancement of high power vacuum BWO´s using nonuniform slow wave structures

Author

Moreland, Larald D. ; Schamiloglu, Edl ; Lemke, Raymond W. ; Korovin, S.D. ; Rostov, V.V. ; Roitman, A.M. ; Hendricks, Kyle J. ; Spencer, T.A.

Author_Institution

Dept. of Electr. & Comput. Eng., New Mexico Univ., Albuquerque, NM, USA

Volume

22

Issue

5

fYear

1994

fDate

10/1/1994 12:00:00 AM

Firstpage

554

Lastpage

565

Abstract

The Sinus-6, a high-power relativistic repetitively-pulsed electron beam accelerator, is used to drive various slow wave structures in a BWO configuration in vacuum. Peak output power of about 550 MW at 9.45 GHz was radiated in an 8-ns pulse. We describe experiments which study the relative efficiencies of microwave generation from a two-stage nonuniform amplitude slow wave structure and its variations without an initial stage. Experimental results are compared with 2.5 D particle-in-cell computer simulations. Our results suggest that prebunching the electron beam in the initial section of the nonuniform BWO results in increased microwave generation efficiency, Furthermore, simulations reveal that, in addition to the backward propagating surface harmonic of the TM₀₁ mode, backward and forward propagating volume harmonics with phase velocity twice that of the surface harmonic play an important role in high-power microwave generation and radiation

Keywords

backward wave oscillators; microwave generation; relativistic electron beam tubes; slow wave structures; vacuum tubes; 550 MW; 8 ns; 9.45 GHz; Sinus-6; TM₀₁ mode; backward propagating surface harmonic; forward propagating volume harmonics; generation efficiency; high power vacuum BWOs; high-power relativistic repetitively-pulsed electron beam accelerator; microwave generation; particle-in-cell computer simulations; peak output power; phase velocity; prebunching; two-stage nonuniform amplitude slow wave structure; Electromagnetic coupling; Electron beams; Electron tubes; Laboratories; Microwave generation; Microwave propagation; Optical coupling; Radio frequency; Space charge; Surface impedance;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.338268

Filename

338268