skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX

Abstract

Lithium as a plasma-facing material has many attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Recent NSTX experiments have shown, for the first time, significant and recurring benefits of lithium coatings on plasma-facing components (PFC's) to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. They included decreases in the plasma density and inductive flux consumption, and increases in the electron temperature, ion temperature, energy confinement time, and DD neutron rate. Extended periods of MHD quiescence were also achieved, and measurements of the visible emission from the lower divertor showed a reduction in the deuterium, carbon, and oxygen line emission. Other salient results with lithium evaporation included a broadening of the electron temperature profile, and changes in edge density gradients that benefited electron Bernstein wave coupling. There was also a reduction in ELM frequency and amplitude, followed by a period of complete ELM suppression. In general, it was observed that both the best and the average confinement occurred after lithium deposition and that the increase in WMHD occurs mostly through an increase in We. Inmore » addition, a liquid lithium divertor (LLD) is being installed on NSTX this year. As the first fully-toroidal liquid metal divertor target, experiments with the LLD can provide insight into the behavior of metallic ITER PFC's should they liquefy during high-power divertor tokamak operations. The NSTX lithium coating and LLD experiments are important near-term steps in demonstrating the potential of liquid lithium as a solution to the first-wall problem for both magnetic and inertial fusion reactors.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
945883
Report Number(s):
LLNL-CONF-409743
TRN: US0901118
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: Presented at: 22nd IAEA FEC, Geneva, Switzerland, Oct 13 - Oct 18, 2008
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; CARBON; COATINGS; CONFINEMENT; CONFINEMENT TIME; DEPOSITION; DEUTERIUM; DIVERTORS; ELECTRON TEMPERATURE; ELECTRONS; EVAPORATION; FIRST WALL; ION TEMPERATURE; LIQUID METALS; LITHIUM; NEUTRONS; OXYGEN; PLASMA DENSITY; RECYCLING; THERMONUCLEAR REACTORS

Citation Formats

Kaita, R, Kugel, H, Bell, M G, Bell, R, Boedo, J, Bush, C, Ellis, R, Gates, D, Gerhardt, S, Gray, T, Kallman, J, Kaye, S, LeBlanc, B, Majeski, R, Maingi, R, Mansfield, D, Menard, J, Mueller, D, Ono, M, Paul, S, Raman, R, Roquemore, A L, Ross, P W, Sabbagh, S, Schneider, H, Skinner, S H, Soukhanovskii, V, Stevenson, T, Stotler, D, Timberlake, J, Zakharov, L, Ahn, J, Allain, J P, and Wampler, W R. Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX. United States: N. p., 2009. Web.
Kaita, R, Kugel, H, Bell, M G, Bell, R, Boedo, J, Bush, C, Ellis, R, Gates, D, Gerhardt, S, Gray, T, Kallman, J, Kaye, S, LeBlanc, B, Majeski, R, Maingi, R, Mansfield, D, Menard, J, Mueller, D, Ono, M, Paul, S, Raman, R, Roquemore, A L, Ross, P W, Sabbagh, S, Schneider, H, Skinner, S H, Soukhanovskii, V, Stevenson, T, Stotler, D, Timberlake, J, Zakharov, L, Ahn, J, Allain, J P, & Wampler, W R. Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX. United States.
Kaita, R, Kugel, H, Bell, M G, Bell, R, Boedo, J, Bush, C, Ellis, R, Gates, D, Gerhardt, S, Gray, T, Kallman, J, Kaye, S, LeBlanc, B, Majeski, R, Maingi, R, Mansfield, D, Menard, J, Mueller, D, Ono, M, Paul, S, Raman, R, Roquemore, A L, Ross, P W, Sabbagh, S, Schneider, H, Skinner, S H, Soukhanovskii, V, Stevenson, T, Stotler, D, Timberlake, J, Zakharov, L, Ahn, J, Allain, J P, and Wampler, W R. Thu . "Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX". United States. https://www.osti.gov/servlets/purl/945883.
@article{osti_945883,
title = {Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX},
author = {Kaita, R and Kugel, H and Bell, M G and Bell, R and Boedo, J and Bush, C and Ellis, R and Gates, D and Gerhardt, S and Gray, T and Kallman, J and Kaye, S and LeBlanc, B and Majeski, R and Maingi, R and Mansfield, D and Menard, J and Mueller, D and Ono, M and Paul, S and Raman, R and Roquemore, A L and Ross, P W and Sabbagh, S and Schneider, H and Skinner, S H and Soukhanovskii, V and Stevenson, T and Stotler, D and Timberlake, J and Zakharov, L and Ahn, J and Allain, J P and Wampler, W R},
abstractNote = {Lithium as a plasma-facing material has many attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Recent NSTX experiments have shown, for the first time, significant and recurring benefits of lithium coatings on plasma-facing components (PFC's) to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. They included decreases in the plasma density and inductive flux consumption, and increases in the electron temperature, ion temperature, energy confinement time, and DD neutron rate. Extended periods of MHD quiescence were also achieved, and measurements of the visible emission from the lower divertor showed a reduction in the deuterium, carbon, and oxygen line emission. Other salient results with lithium evaporation included a broadening of the electron temperature profile, and changes in edge density gradients that benefited electron Bernstein wave coupling. There was also a reduction in ELM frequency and amplitude, followed by a period of complete ELM suppression. In general, it was observed that both the best and the average confinement occurred after lithium deposition and that the increase in WMHD occurs mostly through an increase in We. In addition, a liquid lithium divertor (LLD) is being installed on NSTX this year. As the first fully-toroidal liquid metal divertor target, experiments with the LLD can provide insight into the behavior of metallic ITER PFC's should they liquefy during high-power divertor tokamak operations. The NSTX lithium coating and LLD experiments are important near-term steps in demonstrating the potential of liquid lithium as a solution to the first-wall problem for both magnetic and inertial fusion reactors.},
doi = {},
url = {https://www.osti.gov/biblio/945883}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {1}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: