Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology

Nuclear Fushion

article

V. Perseo¹  F. Effenberg²  D. Gradic¹  R. König¹  O.P. Ford¹  F. Reimold¹  D.A. Ennis⁴  O. Schmitz²  T. Sunn Pedersen¹  the W7-X Team¹ 

[1] Max-Planck-Institut für Plasmaphysik;Department of Engineering Physics, University of Wisconsin;Princeton Plasma Physics Laboratory, Princeton University, Princeton;Auburn University

关键词: island divertor;    magnetic islands;    scrape-off layer;    impurity transport;    plasmaflows;    coherence imaging spectroscopy;   

DOI  :  10.1088/1741-4326/ab4320

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

We report on the first experimental verification of theoretically predicted multiple bundles of counter-streaming plasma flows in the island-divertor scrape-off layer (SOL) of the stellarator Wendelstein 7-X. In the standard toroidal field direction (counter-clockwise when looking from the top) experiments, the overall structure of the SOL flows, such as flow directions, the number of flow bundles and the magnitude of the flow velocities, are consistent with numerical predictions obtained with EMC3-EIRENE. However, the modelling does not predict changes of the flow patterns with reversal of the magnetic field direction, which are experimentally observed. This indicates that additional relevant physics, such as particle drifts, will need to be incorporated into the numerical model to better describe the whole stellarator scrape-off layer behaviour.

【 授权许可】

Unknown