Evaporated lithium surface coatings in NSTX.

Conference · Fri Aug 01 04:00:00 EDT 2008

OSTI ID:947384

Zakharov, L ^[1]; Gates, D ^[1]; Menard, J ^[1]; Maingi, R ^[2]; Schneider, H ^[1]; Mueller, D ^[1]; Wampler, William R; Roquemore, A L ^[1]; Kallman, Jeffrey K ^[1]; Sabbagh, S ^[3]; LeBlanc, B ^[1]; Raman, R ^[4]; Ono, M ^[1]; Wilgren, J ^[2]; Allain, J P ^[5]; Timberlake, J ^[1]; Stevenson, T ^[1]; Ross, P W ^[1]; Majeski, R ^[1]; Kugel, Henry W ^[1] ; Skinner, C H ^[1]; Gerhardt, S ^[1]; Paul, S ^[1]; Bell, R ^[1]; Kaye, S M ^[1]; Kaita, R ^[1]; Soukhanovskii, V ^[6]; Bell, Michael G ^[1]; Mansfield, D ^[1]

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1. Princeton Plasma Physics Laboratory, Princeton, NJ
2. Oak Ridge National Laboratory, Oak Ridge, TN
3. Columbia University, New York, NY
4. University of Washington, Seattle, WA
5. Purdue University, West Lafayette, IN
6. Lawrence Livermore National Laboratory, Livermore, CA

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: (1) plasma density reduction as a result of lithium deposition; (2) suppression of ELMs; (3) improvement of energy confinement in a low-triangularity shape; (4) improvement in plasma performance for standard, high-triangularity discharges; (5) reduction of the required HeGDC time between discharges; (6) increased pedestal electron and ion temperature; (7) reduced SOL plasma density; and (8) reduced edge neutral density.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 947384
• Report Number(s): SAND2008-5405C
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
INTERACTIONS
ION TEMPERATURE
LITHIUM
PLASMA
PLASMA DENSITY
SPHEROMAK DEVICES
SURFACE COATING
SURFACES