Title | Investigation of the critical edge ion heat flux for L-H transitions in Alcator C-Mod and its dependence on BT |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | Schmidtmayr M, Hughes JW, Ryter F, Wolfrum E, Cao NM, Creely AJames, Howard NT, Hubbard AE, Lin Y, Reinke ML, Rice JE, Tolman EA, Wukitch SJ, Ma Y |
Journal | Nuclear Fusion |
Abstract | Abstract This paper presents investigations on the role of the edge ion heat flux for transitions from L-mode to H-mode in Alcator C-Mod. Previous results from the ASDEX Upgrade tokamak indicated that a critical value of edge ion heat flux per particle is needed for the transition. Analysis of C-Mod data confirms this result. The edge ion heat flux is indeed found to increase linearly with density at given magnetic field and plasma current. Furthermore, the Alcator C-Mod data indicate that the edge ion heat flux at the L-H transition also increases with magnetic field. Combining the data from Alcator C-Mod and ASDEX Upgrade yields a general expression for the edge ion heat flux at the L-H transition. These results are discussed from the point of view of the possible physics mechanism of the L-H transition. They are also compared to the L-H power threshold scaling and an extrapolation for ITER is given. |
URL | http://iopscience.iop.org/10.1088/1741-4326/aaaed0 |
Investigation of the critical edge ion heat flux for L-H transitions in Alcator C-Mod and its dependence on <i>B</i><sub><i>T</i></sub>
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