First-wall and limiter conditioning in TFTR

Conference · Mon Oct 01 04:00:00 EDT 1984

OSTI ID:6300915

Dylla, H F; Blanchard, W R; Hawryluk, R J; Hill, K W; Krawchuk, R B; Mueller, D; Owens, D K; Ramsey, A T; Sesnic, S; Tenney, F H

A progress report on the experimental studies of vacuum vessel conditioning during the first year of TFTR operation is presented. A previous paper described the efforts expended to condition the TFTR vessel prior to and during the initial plasma start-up experiments. During the start-up phase, discharge cleaning was performed with the vessel at room temperature. For the second phase of TFTR operations, which was directed towards the optimization of ohmically heated plasmas, the vacuum vessel could be heated to 150/sup 0/C. The internal configuration of the TFTR vessel was more complex during the second phase with the addition of a TiC/C moveable limiter array, Inconel bellows cover plates, and ZrAl getter pumps. A quantitative comparison is given on the effectiveness of vessel bakeout, glow discharge cleaning, and pulse discharge cleaning in terms of the total quantity of removed carbon and oxygen, residual gas base pressures and the resulting plasma impurity levels as measured by visible, uv, and soft x-ray spectroscopy. The initial experience with hydrogen isotope changeover in TFTR is presented including the results of the attempt to hasten the changeover time by using a glow discharge to precondition the vessel with the new isotope.

• Research Organization: Princeton Univ., NJ (USA). Plasma Physics Lab.
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 6300915
• Report Number(s): PPPL-2120; CONF-840520-25; ON: DE85002714
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209* -- Fusion Power Plant Technology-- Component Development & Materials Testing
CARBIDES
CARBON COMPOUNDS
CLEANING
CONTAINERS
ELECTRIC DISCHARGES
FIRST WALL
GLOW DISCHARGES
LIMITERS
OPERATION
PRESSURE VESSELS
TFTR REACTORS
THERMONUCLEAR REACTOR WALLS
THERMONUCLEAR REACTORS
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TOKAMAK TYPE REACTORS
TRANSITION ELEMENT COMPOUNDS