Microwave generation for magnetic fusion energy applications
Abstract
This work strives to develop high average power FEL's at voltages below I MV allowing for smaller and less costly power supplies. To achieve operation of an FEL with 100 GHZ (approx lt) f (approx lt) 150 GHz and with relatively modest voltage, we have been investigating the use of small period ((lambda)(sub (omega)) (approximately) 1 cm) planar wiggler magnets together with sheet electron beams. The sheet beam geometry allows for an FEL interaction region in the form of a narrow slit with high wiggler field at the center plane where the electrons are concentrated. The total current and power may then be increased without making current density excessive by increasing the wide dimension of the sheet beam. Sheet beam FEL design parameters for both a Proof-of-Principle (PoP) FEL experiment, which is current in progress, and an ITER relevant FEL design are shown. A central issue in the sheet beam FEL concept is propagation of the beam through the interaction region without excessive interception by the walls. In section 2 below we describe a successful experimental demonstration of sheet beam propagation through a 56 period uniform wiggler. Cold testing and initial hot test operation of the (PoP) FEL amplifier are also described. Finally, we present a theoretical investigation of the bandwidth of an FEL amplifier with a tapered wiggler operating in saturation is described.
- Publication:
-
Unknown
- Pub Date:
- February 1993
- Bibcode:
- 1993mgmf.rept.....A
- Keywords:
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- Cyclotron Resonance Devices;
- Electron Beams;
- Free Electron Lasers;
- Microwave Amplifiers;
- Nuclear Fusion;
- Wiggler Magnets;
- Amplifier Design;
- Computerized Simulation;
- Design Analysis;
- Electron Cyclotron Heating;
- Harmonic Oscillators;
- High Frequencies;
- Waveguides;
- Lasers and Masers