Experimental study of a 1MW, 170 GHz gyrotron with internal mode converter

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:153881

Kimura, T; Danly, B G; Kreischer, K E; Temkin, R J ^[1]

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1. Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Fusion Center

A high frequency gyrotron suitable for Electron Cyclotron Heating (ECH) of the International Thermonuclear Experimental Reactor (ITER) is being investigated at MIT. The goal is to demonstrate efficient operation at a power level in excel of 1 MW with a Gaussian output beam. The gyrotron is designed to operate in the TE{sub 28.8} mode at 170 GHz. A standard tapered cavity is used. A large input angle and short interaction length are chosen to avoid multimoding. Self consistent theory predicts 1.2 MW output power with 77 kV beam energy. 38 Ampere beam current for an efficiency of 45%. The magnetic field is provided by a 7.5T superconducting magnet which is currently being built by Cryomagnetics. This magnet has a 8 inch diameter horizontal warm bore and a 20 inch axial length. The rated maximum field is 7.5T at 4.2K and 9.0T at 2.2K. The internal mode converter is designed to transform the TE{sub 28.8}, cylindrical waveguide mode at 170 GHz to a Gaussian beam in free space. The mode converter consists of a rippled wall section with a stepcut launching aperture and four mirrors for beam steering and shaping. The mode conversion efficiency is calculated to be 90%.

• OSTI ID: 153881
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DESIGN
ECR HEATING
ITER TOKAMAK
MICROWAVE AMPLIFIERS
MODE CONVERSION
OPERATION
OSCILLATION MODES
PERFORMANCE