W-band Gyro-BWO using a helically corrugated waveguide

Author

Donaldson, C.R. ; He, W. ; Phelps, A.D.R. ; Li, F. ; Cross, A.W. ; Ronald, K. ; Young, A.R. ; Whyte, C.G.

Author_Institution

Dept. of Phys., Univ. of Strathclyde, Glasgow, UK

fYear

2008

fDate

6-11 July 2008

Firstpage

1

Lastpage

2

Abstract

Presented in this paper is the design of a W-Band Gyro-BWO with a helically corrugated waveguide and a cusp electron gun. The interaction region has been constructed with good accuracy and microwave results measured using a vector network analyzer are given. The microwave dispersion agrees well with analytical and numerical theory. The transmission loss of this helically corrugated waveguide was measured to be ~1dB over the frequency range (84 - 104GHz). A cusp electron gun has been designed to generate a 1.5A, 40kV electron beam with an adjustable pitch angle (α) of up to 3. The beam was optimized through numerical simulation with an axial velocity spread, ΔV_z/V_z, of 7% and Δα/α, of 10.4% at α=1.65. From simulation of the beam-wave interaction the maximum output power from the Gyro-BWO was predicted to be 10kW (CW) at 17% efficiency, with a 3dB frequency tuning range of ~84-104GHz.

Keywords

backward wave oscillators; electron guns; millimetre wave oscillators; waveguides; W-band gyro-BWO; analytical theory; axial velocity spread; beam-wave interaction; current 1.5 A; cusp electron gun; efficiency 17 percent; electron beam; frequency 84 GHz to 104 GHz; helically-corrugated waveguide; microwave dispersion; numerical theory; pitch angle; power 10 kW; transmission loss; vector network analyzer; voltage 40 kV; Cathodes; Coils; Current measurement; Design automation; Heating; Numerical simulation;

fLanguage

English

Publisher

ieee

Conference_Titel

High Power Particle Beams (BEAMS), 2008 17th International Conference on

Conference_Location

Xian

Type

conf

Filename

6202971