Reduction of recycling in DIII-D by degassing and conditioning of the graphite tiles

Conference · Sun May 01 00:00:00 EDT 1988

OSTI ID:6888967

Jackson, G L; Taylor, T S; Allen, S L; Ferron, J; Haas, G; Hill, D; Mahdavi, M A; Nakamura, H; Osborne, T H; Petersen, P I

Reduced recycling, reduced edge neutral pressure, improved density control, and improved discharge reproducibility have been achieved in the DIII-D tokamak by in situ helium conditioning of the graphite tiles. An improvement in energy confinement has been observed in hydrogen discharges with hydrogen beam injection after helium preconditioning. After the graphite wall coverage in DIII-D was increased to 40%, helium glow wall conditioning, routinely applied before each tokamak discharge, has been necessary to reduce recycling and obtain H-mode. The utilization of helium glow wall conditioning was an important factor in the achievement of an ohmic H-mode, i.e. no auxillary heating, with significant improvement in ohmic energy confinement. 16 refs., 8 figs.

• Research Organization: General Atomic Co., San Diego, CA (USA)
• DOE Contract Number: AC03-84ER51044; W-7405-ENG-48
• OSTI ID: 6888967
• Report Number(s): GA-A-19295; CONF-880512-10; ON: DE88012816
• Resource Relation: Conference: 8. international conference on plasma surface interactions in controlled fusion devices, Julich, F.R. Germany, 2 May 1988; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DOUBLET-3 DEVICE
THERMONUCLEAR REACTOR MATERIALS
GRAPHITE
CONFINEMENT TIME
DEGASSING
DIVERTORS
LIMITERS
NEUTRAL ATOM BEAM INJECTION
BEAM INJECTION
CARBON
CLOSED PLASMA DEVICES
ELEMENTAL MINERALS
ELEMENTS
MATERIALS
MINERALS
NONMETALS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
700209* - Fusion Power Plant Technology- Component Development & Materials Testing