110 GHz ECH system for DIII-D

Conference · Wed May 01 04:00:00 EDT 1991

OSTI ID:5837501

Moeller, C; Callis, R; DeHope, W; Doane, J; Freeman, R; Prater, R; Remsen, D; Sevier, L

Electron cyclotron heating (ECH) has proven effective for localized heating and current drive applications in tokamaks. This ECH system is designed to support experiments on H-mode physics, noninductively ECH driven plasma current ({approx}500 kA), and localized heating for plasma stabilization in the presence of substantial neutral beam power. The second harmonic X-mode will be launched from the outside using a mirror that can be rotated in the poloidal and toroidal directions. In order to satisfy the physics objectives, it is necessary not only that the microwave power be transmitted from the gyrotron to the plasma efficiently and reliably for pulses as long as 10 seconds, but that the power be transmitted in a single mode, so that the radiation pattern is narrow and independent of small changes in gyrotron operating conditions. Noteworthy features of the transmission system, are: A novel mode converter from the gyrotron TE{sub 15,2} mode to the HE{sub 11} mode in which the power is contained entirely in waveguide; a relatively small waveguide diameter (1.25 in.) for transmission of the low-loss HE{sub 11} model; an all-vacuum system to ensure reliability at high power; a windowless system using differential pumping together with a fast shutter to avoid contaminating the tokamak vacuum; a quasi-optical launcher using a steerable mirror.

• Research Organization: General Atomics, San Diego, CA (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC03-89ER51114
• OSTI ID: 5837501
• Report Number(s): GA-A-20471; CONF-910609--16; ON: DE91013238
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700205* -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
AMPLIFIERS
DOUBLET REACTORS
ECR HEATING
ELECTRONIC EQUIPMENT
EQUIPMENT
HEATING
HIGH-FREQUENCY HEATING
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
PLASMA HEATING
PUMPING
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
VACUUM SYSTEMS
WAVEGUIDES