Experimental studies of high-power plasma-filled backward wave oscillators

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6922087

Lou, W

High power X-band microwave radiation from a plasma filled backward wave oscillator (BWO) driven by an intense relativistic electron beam was studied experimentally. It was demonstrated that a plasma filled BWO can operate at an enhanced efficiency of 40 percent compared with a typical efficiency of 20 percent in a vacuum BWO under the same conditions at low current regime. The radiation frequency was coherent (delta f/f is approximately 0.35 percent) and could be tuned by changing the plasma density. The plasma BWO was found to operate efficiently at magnetic fields as low as 800 G, and with a wide range of magnetic fields, except at the two cyclotron absorption dips, which probably correspond to the first and third harmonic cyclotron waves. The start oscillation current was obtained experimentally for vacuum BWO and plasma loaded BWO. It was also show that the spectrum of the conventional low frequency (omega less than omega[sub p]) Trivelpiece-Gould modes was drastically modified by the periodicity of the structure in a way that produced a fundamentally new sort of spectral behavior, the dense spectrum. The radiation leaking out of the plasma was measured.

• Research Organization: Maryland Univ., College Park, MD (United States)
• OSTI ID: 6922087
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426000* -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
BACKWARD WAVE TUBES
BEAMS
BREMSSTRAHLUNG
CYCLOTRON RADIATION
EFFICIENCY
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUIPMENT
LEPTON BEAMS
MAGNETIC FIELDS
MICROWAVE EQUIPMENT
MICROWAVE RADIATION
MICROWAVE TUBES
PARTICLE BEAMS
PLASMA
PLASMA DENSITY
PLASMA WAVES
RADIATIONS
RELATIVISTIC RANGE