Experimental results for a 1.5 MW, 110 GHz gyrotron with an improved cavity

Author

Choi, E.M. ; Marchewka, C. ; Sirigiri, J.R. ; Shapiro, M.A. ; Temkin, R.J.

Author_Institution

Plasma Sci. & Fusion Center, MIT, Cambridge, MA, USA

Volume

1

fYear

2005

fDate

19-23 Sept. 2005

Firstpage

241

Abstract

Recently, a cavity (named V-2005) has been designed and successfully tested for the 1.5 MW, 110 GHz gyrotron experiment at MIT. The novel feature of the cavity lies in its low diffractive Q factor which corresponds to reducing the Ohmic loss on the cavity wall. The design and mode competition analysis were done with the simulation code, MAGY. In short pulse experiments, we achieved 1.67 MW of output power with an efficiency of 42 % at 97 kV of beam voltage and 41 A of current. Compared to the previous cavity (named V-2003), the new cavity has a smaller output taper angle and the Ohmic loss has been reduced by 25 %. The experimental result shows an increase in efficiency (42 % vs. 37 %) in the new cavity compared to the previous one. A map of the observed modes was generated by varying the cathode and cavity magnetic fields for both cavities. Less competition from the TE_19.7 mode was observed in the V-2005 cavity.

Keywords

Q-factor; circuit analysis computing; gyrotrons; 1.5 MW; 1.67 MW; 110 GHz; 41 A; 42 percent; 97 kV; MAGY simulation; Q factor; TE_19.7 mode; V-2005 cavity; cathode magnetic field; cavity magnetic field; cavity wall; improved cavity gyrotron; mode competition analysis; ohmic loss; taper angle; Analytical models; Cathodes; Diffraction; Gyrotrons; Magnetic fields; Power generation; Q factor; Tellurium; Testing; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics, 2005. IRMMW-THz 2005. The Joint 30th International Conference on

Print_ISBN

0-7803-9348-1

Type

conf

DOI

10.1109/ICIMW.2005.1572498

Filename

1572498