Experimental results and numerical simulations of a high power 140 GHz gyrotron

Author

Gantenbein, G. ; Borie, E. ; Dammertz, G. ; Kuntze, M. ; Nickel, H.-U. ; Piosczyk, B. ; Thumm, M.

Author_Institution

Inst. fur Tech. Phys., Kernforschungszentrum Karlsruhe, Germany

Volume

22

Issue

5

fYear

1994

fDate

10/1/1994 12:00:00 AM

Firstpage

861

Lastpage

870

Abstract

The design of a 0.5 MW 140 GHz gyrotron with axial RF output operating in the TE_10,4 mode is presented. Experimental results and numerical simulations are compared. In particular the effects of RF reflections at the output window, velocity spread of the helical electron beam and startup of oscillations by simultaneous increase of pitch factor α and relativistic factor γ are discussed. In short pulse operation (⩽5 ms) an output power of 690 kW has been obtained with an electronic efficiency of 31% and a mode purity of about 99%. The experiments have shown that it is possible to use for step frequency tuning the azimuthal neighbours of the TE_10,4 mode, TE_9.4 at 132.6 GHz (420 kW) and TE _11,4 at 147.3 GHz (300 kW) as working modes by decreasing and increasing the magnetic field, respectively

Keywords

CAD; digital simulation; electronic engineering computing; gyrotrons; starting; 0.5 MW; 132.6 GHz; 140 GHz; 147.3 GHz; 300 kW; 31 percent; 420 kW; 690 kW; ECR; RF reflections; axial RF output; azimuthal neighbours; electronic efficiency; gyrotron; helical electron beam; mode purity; numerical simulations; oscillations; output window; pitch factor; relativistic factor; startup; step frequency tuning; velocity spread; Cogeneration; Cyclotrons; Gyrotrons; Heating; Nickel; Numerical simulation; Plasma stability; Plasma temperature; Power generation; Radio frequency;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.338301

Filename

338301