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Title: The DIII-D 3 MW, 110 GHz ECH system

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.59703· OSTI ID:20216718
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  1. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

Three 110 GHz gyrotrons with nominal output power of 1 MW each have been installed and are operational on the DIII-D tokamak. One gyrotron is built by Gycom and has a nominal rating of 1 MW and a 2 s pulse length, with the pulse length being determined by the maximum temperature allowed on the edge cooled Boron Nitride window. The second and third gyrotrons were built by Communications and Power Industries (CPI). The first CPI gyrotron uses a double disc FC-75 cooled sapphire window which has a pulse length rating of 0.8 s at 1 MW, 2 s at 0.5 MW and 10 s at 0.35 MW. The second CPI gyrotron, utilizes a single disc chemical-vapor-deposition diamond window, that employs water cooling around the edge of the disc. Calculation predict that the diamond window should be capable of full 1 MW cw operation. All gyrotrons are connected to the tokamak by a low-loss-windowless evacuated transmission line using circular corrugated waveguide for propagation in the HE{sub 11} mode. Each waveguide system incorporates a two mirror launcher which can steer the rf beam poloidally from the center to the outer edge of the plasma. Central current drive experiments with the two gyrotrons with 1.5 MW of injected power drove about 0.17 MA. Results from using the three gyrotron systems will be reported as well as the plans to upgrade the system to 6 MW. (c) 1999 American Institute of Physics.

OSTI ID:
20216718
Journal Information:
AIP Conference Proceedings, Vol. 485, Issue 1; Other Information: PBD: 20 Sep 1999; ISSN 0094-243X
Country of Publication:
United States
Language:
English