First operation of a wiggler-focused, sheet beam free electron laser amplifier

Journal Article · Sun May 01 00:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870674· OSTI ID:6691648

Destler, W W; Cheng, S; Zhang, Z X; Antonsen, Jr, T M; Granatstein, V L; Levush, B; Rodgers, J ^[1]

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

A wiggler-focused, sheet beam free electron laser (FEL) amplifier utilizing a short-period wiggler magnet has been proposed as a millimeter-wave source for current profile modification and/or electron cyclotron resonance heating of tokamak plasmas. As proposed, such an amplifier would operate at a frequency of approximately 100--200 GHz with an output power of 1--10 MW CW. Electron beam energy would be in the range 500--1000 keV. To test important aspects of this concept, an initial sheet beam FEL amplifier experiment has been performed using a 1 mm[times]2 cm sheet beam produced by a pulse line accelerator with a pulse duration of 100 ns. The 500--570 keV, 4--18 A sheet beam is propagated through a 56 period uniform wiggler ([lambda][sub [ital w]]=9.6 mm) with a peak wiggler amplitude of 2--5 kG. Linear amplification of a 5--10 W, 94 GHz signal injected in the TE[sub 01] rectangular mode is observed. All features of the amplified signal, including pulse shape and duration, are in accordance with the predictions of numerical simulation. Amplified signal gain has been measured as a function of injected beam energy, current, and wiggler field amplitude and is also in good agreement with simulation results. Continuation of this experiment will involve studying nonlinear amplifier operation and adding a section of tapered wiggler.

• OSTI ID: 6691648
• Journal Information: Physics of Plasmas; (United States), Vol. 1:5; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FREE ELECTRON LASERS
AMPLIFIERS
ELECTRON BEAMS
ELECTRON CYCLOTRON-RESONANCE
PLASMA HEATING
RADIOWAVE RADIATION
TOKAMAK DEVICES
WIGGLER MAGNETS
BEAMS
CLOSED PLASMA DEVICES
CYCLOTRON RESONANCE
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELECTROMAGNETS
ELECTRONIC EQUIPMENT
EQUIPMENT
HEATING
LASERS
LEPTON BEAMS
MAGNETS
PARTICLE BEAMS
RADIATIONS
RESONANCE
THERMONUCLEAR DEVICES
700350* - Plasma Production
Heating
Current Drive
& Interactions- (1992-)