Quantitative comparison of impurity transport in turbulence reduced and enhanced scenarios at Wendelstein 7-X

Nuclear Fushion

article

J.A. Alcusón¹  Th. Wegner¹  A. Dinklage¹  A. Langenberg¹  J.-P. Bähner³  B. Buttenschön¹  E.M. Edlund⁴  G. Fuchert¹  J.M. García-Regaña⁵  O. Grulke¹  Z. Huang⁷  M. Porkolab³  A.V. Stechow¹  P. Xanthopoulos¹  A. Zocco¹  the W7-X Team¹ 

[1] Max-Planck Institute for Plasma Physics;Laboratorio de Innovación en Plasmas, University of Cordoba;MIT Plasma Science and Fusion Center;SUNY Cortland;Laboratorio Nacional de Fusión;Technical University of Denmark;UKAEA, Culham Centre for Fusion Energy, Culham Science Centre

关键词: pedestal;    MHD;    tokamak;    drift waves;    turbulence spreading;   

DOI  :  10.1088/1741-4326/aceb76

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

We assess the turbulent particle transport being responsible for the limitation of the confinement and, thus, the overall performance of the neoclassically optimized stellarator Wendelstein 7-X. The radial particle transport is experimentally inferred from the evaluation of impurity injection into turbulence reduced and enhanced plasma scenarios revealing a completely different confinement behavior. The impact of the density gradient on the turbulent ion transport is theoretically estimated using large-scale non-linear gyro-kinetic simulations enabling, for the first time in Wendelstein 7-X, a quantitative comparison to the experimentally assessed impurity transport properties. We demonstrate that impurity transport in most of the Wendelstein 7-X discharges, up to now impossible to cover only with neoclassical estimations, is dominated by turbulence and can be modelled via gyro-kinetic simulations.

【 授权许可】

Unknown