Modification Of The Electron Energy Distribution Function During Lithium Experiments On The National Spherical Torus Experiment
Authors: M.A. Jaworski, M.G. Bell, T.K. Gray, R. Kaita, J. Kallman, H. Kugel, B. LeBlanc, A. McLean, S.A. Sabbagh, V. Soukhanovskii, D.P. Stotler, V. Surla
Abstract:
The National Spherical Torus Experiment (NSTX) has recently studied
the use of a liquid lithium divertor (LLD). Divertor Langmuir probes have
also been installed for making measurements of the local plasma conditions.
A non-local probe interpretation method is used to supplement the classical
probe interpretation and obtain measurements of the electron energy
distribution function (EEDF) which show the occurrence of a hot-electron
component. Analysis is made of two discharges within a sequence that exhibited
changes in plasma fueling efficiency. It is found that the local electron
temperature increases and that this increase is most strongly correlated with
the energy contained within the hot-electron population. Preliminary interpretative
modeling indicates that kinetic effects are likely in the NSTX.
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Submitted to: Fusion Engineering and Design (May 2011)
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Download PPPL-4631 (pdf 729KB 32 pp)
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