Experimental studies of stability and amplification in a two-cavity second harmonic gyroklystron

Author

Matthews, H.W. ; Lawson, W. ; Calame, J.P. ; Flaherty, M.K.E. ; Hogan, B. ; Cheng, J. ; Latham, P.E.

Author_Institution

Lab. for Plasma Res., Maryland Univ., College Park, MD, USA

Volume

22

Issue

5

fYear

1994

fDate

10/1/1994 12:00:00 AM

Firstpage

825

Lastpage

833

Abstract

We report the operating characteristics of a sequence of two-cavity second harmonic gyroklystrons which are derived in part from a previous fundamental tube and utilize output cavities which resonate at twice the drive frequency. We present results from the design simulations as well as details of the stable range of operating parameters. While the harmonic tube is somewhat more susceptible to spurious oscillations and more sensitive to parameter variations than the fundamental device, there is still considerable parameter space available for amplifier operation. Peak powers above 30 MW are obtained with efficiencies greater than 28% and large signal gains of 27 dB. These results depend critically on the magnetic field profile which has a slight up-taper at the optimum operating point. The nominal beam parameters include a pulse length of 1 μs, a voltage near 450 kV, a current in the range 235-245 A, and a perpendicular to parallel velocity ratio (α=v_⊥/v_z) near one

Keywords

cavity resonators; gyrotrons; harmonics; klystrons; microwave power amplifiers; plasma instability; 1 mus; 235 to 245 A; 27 dB; 28 percent; 30 MW; 450 kV; amplifier operation; design simulations; magnetic field profile; nominal beam parameters; operating characteristics; output cavities; parameter space; pulse length; spurious oscillations; stability; two-cavity second harmonic gyroklystron; velocity ratio; Cyclotrons; Frequency; Gyrotrons; Klystrons; Magnetic fields; Magnetic resonance; Particle beams; Pulse amplifiers; Stability; Voltage;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.338298

Filename

338298