Publications Details

Far scrape-off layer and near wall plasma studies in DIII-D

Rudakov, D.L.; Boedo, J.A.; Moyer, R.A.; Brooks, N.H.; Doerner, R.P.; Evans, T.E.; Fenstermacher, M.E.; Groth, M.; Hollmann, E.M.; Krasheninnikov, S.; Lasnier, C.J.; Mahdavi, M.A.; McKee, G.R.; McLean, A.; Stangeby, P.C.; Wampler, W.R.; Watkins, J.G.; West, W.P.; Whyte, D.G.; Wong, C.P.C.

Far scrape-off layer (SOL) plasma parameters in DIII-D depend strongly on the discharge density and confinement regime. In L-mode, cross-field transport increases with the average discharge density and elevates the far SOL density, thus increasing plasma-wall contact. Far SOL density near the low field side (LFS) of the main chamber wall also increases with decreasing plasma current and with decreasing outer wall gap. In H-mode, between edge localized modes (ELMs), plasma-wall contact is weaker than in L-mode. During ELMs plasma fluxes to the LFS wall increase to, or above the L-mode levels. A large fraction of the net cross-field fluxes is convected through the SOL by large amplitude intermittent transport events. In high-density L-mode and during ELMs in H-mode, intermittent events propagate all the way to the LFS wall and may cause sputtering. © 2004 Elsevier B.V. All rights reserved.