The effect of limiter conditioning on the Tokamak Fusion Test Reactor edge plasma

Journal Article · Wed May 01 00:00:00 EDT 1991 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA)

DOI:https://doi.org/10.1116/1.577355· OSTI ID:5603505

Kilpatrick, S J; Pitcher, C S; Dylla, H F; Manos, D M; Nyberg, I; Ramsey, A T; Stratton, B C; Timberlake, J; Ulrickson, M J ^[1]

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1. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (USA)

Measurements by moveable Langmuir probes and edge spectroscopy diagnostics have documented the conditioning effect of low-density helium-initiated discharge sequences on the Tokamak Fusion Test Reactor edge plasma. Langmuir probe measurements shown in general that the edge electron density {ital n}{sub {ital e}} decreases by less than a factor of 2 while the edge electron temperature {ital T}{sub {ital e}} doubles. Radial profiles to the plasma boundary show that the density scrape-off length increases somewhat while the temperature scrape-off length decreases substantially. The particle flux density is unaffected. The spectral emission of C II decreases by a factor of 2, a much smaller change than that exhibited by the {ital D}{sub {alpha}} signal. These results complement previous accounts of the conditioning technique. Comparisons of these He conditioning measurements are made to edge measurements during a deuterium density scan experiment, showing many similarities, and to an existing edge model of the conditioning process, showing qualitative agreement.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5603505
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA), Vol. 9:3; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TFTR TOKAMAK
LIMITERS
ELECTRIC DISCHARGES
ELECTRON DENSITY
HELIUM
LANGMUIR PROBE
PLASMA
PLASMA DIAGNOSTICS
ELECTRIC PROBES
ELEMENTS
FLUIDS
GASES
NONMETALS
PROBES
RARE GASES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing