Scaling studies and time-resolved microwave measurements on a relativistic backward-wave oscillator

Journal Article · Wed Dec 01 04:00:00 EST 1993 · IEEE Transactions on Plasma Science

DOI:https://doi.org/10.1109/27.256791· OSTI ID:142412

Swegle, J A; Anderson, R A; Camacho, J F; Poole, B R; Rhodes, M A; Rosenbury, E T; Shaeffer, D L ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

The authors built a relativistic backward-wave oscillator (BWO) operating at a frequency near 8 GHz. In the experiments, the parameters of the 60-ns electron beam driving this microwave source were varied over the ranges 0.8--1.5 MV and 2--10 kA. Also, they tried several different annular cathodes for launching the electron beam varying the outer radius and shape. The axial magnetic field guiding the beam through the BWO was varied between 0.6 and 3 T. Finally, they investigated the power transfer downstream to an output waveguide as a function of the shape of the transition from the BWO to the waveguide. They discuss the scaling of the output power and frequency with these variations. In addition, they show time-resolved measurements of 2-ns-long segments of the microwave output. In observations of the microwave signal, they found the frequency shifted as the output power envelope passed through a sharp dip; they propose that this shift corresponds to a change in the longitudinal operating mode of the BWO.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 142412
• Journal Information: IEEE Transactions on Plasma Science, Journal Name: IEEE Transactions on Plasma Science Journal Issue: 6 Vol. 21; ISSN ITPSBD; ISSN 0093-3813
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BACKWARD WAVE TUBES
ENERGY TRANSFER
EXPERIMENTAL DATA
FREQUENCY MEASUREMENT
OSCILLATION MODES
SCALING LAWS