High power operation of first and second harmonic gyrotwystrons

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.360639· OSTI ID:64908

Lawson, W; Latham, P E; Calame, J P; Cheng, J; Hogan, B; Nusinovich, G S; Irwin, V; Granatstein, V L; Reiser, M ^[1]

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1. Institute for Plasma Research and Electrical Engineering Department, University of Maryland, College Park, Maryland 20742 (United States)

We report the first experimental operation of overmoded first and second harmonic gyrotwystron amplifier configurations. Both devices utilize a single cavity which is driven near 9.87 GHz in the TE{sub 011} mode, heavily attenuated drift tubes, and long tapered output waveguide sections. A magnetron injection gun produces a 460 kV, 245 A beam with a maximum average perpendicular-to-parallel velocity ratio approximately equal to one. The axial magnetic field profile is sharply tapered in the output section. Peak powers above 21 MW are achieved in 1 {mu}s pulses with an efficiency exceeding 22% and a large signal gain near 24 dB in the first harmonic tube. The second harmonic tube achieves nearly 12 MW of the peak power with an efficiency of 11% and a gain above 21 dB. First harmonic amplifier performance is limited principally by competition from a fundamental mode output waveguide interaction; the second harmonic tube is limited by both travelling wave output modes and by a down-taper oscillation. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 64908
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 78; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
DRIFT TUBES
ELECTRON BEAMS
GHZ RANGE
HARMONICS
MAGNETIC FIELDS
MEGAWATT POWER RANGE
MICROWAVE AMPLIFIERS
OPERATION
RELATIVISTIC RANGE
WAVEGUIDES