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

Conference · Mon Jul 01 00:00:00 EDT 1991

OSTI ID:5447803

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

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 (TFTR) edge plasma. Langmuir probe measurements show in general that the edge electron density n{sub e} decreases by less than a factor of 2 while the edge electron temperature T{sub 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 2 decreases by a factor of 2, a much smaller change than that exhibited by the 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. 20 refs., 5 figs.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5447803
• Report Number(s): PPPL-2774; CONF-901035-18; ON: DE91016210; TRN: 91-023746
• Resource Relation: Conference: 37. national American Vacuum Society symposium, Toronto (Canada), 8-12 Oct 1990
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TFTR TOKAMAK
H-MODE PLASMA CONFINEMENT
DEUTERIUM
ELECTRON DENSITY
FLUX DENSITY
GRAPHITE
HELIUM
LANGMUIR PROBE
LIMITERS
PLASMA IMPURITIES
PLASMA SCRAPE-OFF LAYER
TEMPERATURE DISTRIBUTION
BOUNDARY LAYERS
CARBON
CONFINEMENT
ELECTRIC PROBES
ELEMENTAL MINERALS
ELEMENTS
FLUIDS
GASES
HYDROGEN ISOTOPES
IMPURITIES
ISOTOPES
LAYERS
LIGHT NUCLEI
MINERALS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PLASMA CONFINEMENT
PROBES
RARE GASES
STABLE ISOTOPES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing
700101 - Fusion Energy- Plasma Research- Confinement
Heating
& Production