Local Effects of Biased Electrodes in the Divertor of NSTX
Authors: S. Zweben, M.D. Campanell, B.C. Lyons, R.J. Maqueda, Y. Raitses, A.L. Roquemore and F. Scotti
Abstract:
The goal of this paper is to characterize the effects of small non-axisymmetric
divertor plate electrodes on the local scrape-off layer plasma. Four small rectangular
electrodes were installed into the outer divertor plates of NSTX. When the electrodes
were located near the outer divertor strike point and biased positively, there was an
increase in the nearby probe currents and probe potentials and an increase in the LiI light
emission at the large major radius end of these electrodes. When an electrode located
farther outward from the outer divertor strike point was biased positively, there was
sometimes a significant decrease in the LiI light emission at the small major radius end of
this electrode, but there were no clear effects on the nearby probes. No non-local effects
were observed with the biasing of these electrodes.
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Submitted to: Plasma Physics and Controlled Fusion (May 2012)
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Download PPPL-4760 (pdf 5.18 MB 47 pp)
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