Design of a low-voltage, axially modulated, cusp-injected, third harmonic, X-band gyrotron amplifier experiment

Author

Liu, Arnold ; Lawson, Wes ; Fernandez, Anna ; Rodgers, John ; Destler, William W.

Author_Institution

Dept. of Electr. Eng., Maryland Univ., College Park, MD, USA

Volume

44

Issue

11

fYear

1997

fDate

11/1/1997 12:00:00 AM

Firstpage

2022

Lastpage

2028

Abstract

We present the design of a prebunched, third harmonic small-orbit gyrotron experiment that utilizes a 45 kV, 8 A beam to produce over 185 kW of amplified power at 9.9 GHz in a 1.23 kG magnetic field. We detail the design of the electron gun, which produces a moderately compressed axially streaming annular beam. The beam is velocity modulated by a short TM₀₁₀ coaxial input cavity and energy is extracted in a right-circular TE₀₂₁ output cavity. Perpendicular energy is imparted to the beam via a nonadiabatic magnetic transition at the end of a 23 cm drift region between the two cavities. A nonlinear single particle code is used to predict an electronic efficiency of 52% and a large signal gain of 25.5 dB. This code generates the cavity field profiles via a scattering matrix formalism and uses the output from the electron gun code to model the beam. This improved model allows the potentially important effects of leakage fields and finite beam thickness and spread to be investigated

Keywords

S-matrix theory; electron guns; gyrotrons; microwave amplifiers; 1.23 kG; 185 kW; 23 cm; 25.5 dB; 45 kV; 52 percent; 8 A; 9.9 GHz; TM₀₁₀ coaxial input cavity; X-band; axially modulated device; cavity field profiles; cusp-injected device; drift region; electron gun; electronic efficiency; finite beam thickness; gyrotron amplifier experiment; leakage fields; moderately compressed axially streaming annular beam; nonadiabatic magnetic transition; nonlinear single particle code; perpendicular energy; right-circular TE₀₂₁ output cavity; scattering matrix formalism; signal gain; small-orbit gyrotron; third harmonic; velocity modulation; Coaxial components; Electron beams; Gain; Gyrotrons; Magnetic fields; Optical modulation; Particle scattering; Power system harmonics; Tellurium; Transmission line matrix methods;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.641375

Filename

641375