Title | Results from recent detachment experiments in alternative divertor configurations on TCV |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | C. Theiler, B. Lipschultz, J. Harrison, B. Labit, H. Reimerdes, C. Tsui, W.AJ Vijvers, J.A Boedo, B.P Duval, S. Elmore, P. Innocente, U. Kruezi, T. Lunt, R. Maurizio, F. Nespoli, U. Sheikh, A.J Thornton, S.HM van Limpt, K. Verhaegh, N. Vianello, TCV team, EUROfusion MST1 Team |
Journal | Nuclear Fusion |
Volume | 57 |
Issue | 7 |
Pagination | 072008 |
Abstract | Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical TCV single-null shapes, the poloidal flux expansion at the outer strikepoint is varied by a factor of 10 to investigate the X-divertor characteristics, and the total flux expansion is varied by 70% to study the properties of the super-X divertor. The effect of an additional X-point near the target is investigated in X-point target divertors. Detachment of the outer target is studied in these plasmas during Ohmic density ramps and with the ion {$\nabla $} B drift away from the primary X-point. The detachment threshold, depth of detachment, and the stability of the radiation location are investigated using target measurements from the wall-embedded Langmuir probes and two-dimensional CIII line emissivity profiles across the divertor region, obtained from inverted, toroidally-integrated camera data. It is found that increasing poloidal flux expansion results in a deeper detachment for a given line-averaged density and a reduction in the radiation location sensitivity to core density, while no large effect on the detachment threshold is observed. The total flux expansion, contrary to expectations, does not show a significant influence on any detachment characteristics in these experiments. In X-point target geometries, no evidence is found for a reduced detachment threshold despite a 2–3 fold increase in connection length. A reduced radiation location sensitivity to core plasma density in the vicinity of the target X-point is suggested by the measurements. |
DOI | 10.1088/1741-4326/aa5fb7 |
Division | FP |
Department | PEPD |
PID | 3d6da7105690d0eb6e595185f9ed42ee |
Alternate Title | Nucl. Fusion |
Label | OA |
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