Three-dimensional simulations of edge impurity flow obtained by the vacuum ultraviolet emission diagnostics in the Large Helical Device with EMC3-EIRENE

Nuclear Fushion

article

S.Y. Dai¹  T. Oishi²  G. Kawamura²  M. Kobayashi²  S. Morita²  Y. Feng⁴  D.Z. Wang¹ 

[1] Key Laboratory of Materials Modification by Laser, Ion and Electron Beams ,(Ministry of Education), School of Physics, Dalian University of Technology;National Institute for Fusion Science, National Institutes of Natural Sciences;Department of Fusion Science, School of Physical Sciences, SOKENDAI ,(The Graduate University for Advanced Studies);Max-Planck-Institut für Plasmaphysik

关键词: SOL/divertor plasma;    impurity flow;    spectrometer;    LHD;   

DOI  :  10.1088/1741-4326/aace69

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

Edge carbon impurity flow in the stochastic layer of the Large Helical Device (LHD) has been investigated with the three-dimensional (3D) edge transport code EMC3-EIRENE. The simulated synthetic C³⁺ impurity flow profile from EMC3-EIRENE shows a reasonable agreement with the vacuum ultraviolet (VUV) measurements according to the CIV (1548.20   ×   2 Å) Doppler- shift spectrum. The same horizontally outward C³⁺ impurity flows at the top and bottom edges of the stochastic layer are determined by the 3D magnetic field structure and the parallel C³⁺ impurity flow velocity. The observed up-down asymmetric structure of the C³⁺ impurity flow at the top and bottom edges is caused by the vertical displacement of the VUV spectrometer from the midplane. The horizontally outward shift of the magnetic axis position from 3.6 to 3.9 m leads to a change of the C³⁺ impurity flow direction at the top and bottom edges. For a high upstream plasma density, the transport of the C³⁺ impurity flow is mainly determined by the background parallel plasma flow, while a reversed C³⁺ impurity flow is obtained for a low upstream plasma density, due to the expansion of the thermal force dominant regions. The enhanced thermal force leads to a suppression of the impurity screening effect.

【 授权许可】

Unknown