Open AccessPlasma filaments in the scrape-off layer of Wendelstein 7-X
Author(s) -
C. Killer,
B. Shanahan,
O. Grulke,
M. Endler,
Kenneth Hammond,
L. Rudischhauser
Publication year - 2020
Publication title -
plasma physics and controlled fusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.328
H-Index - 111
eISSN - 1361-6587
pISSN - 0741-3335
DOI - 10.1088/1361-6587/ab9313
Subject(s) - wendelstein 7 x , protein filament , stellarator , plasma , curvature , physics , flux (metallurgy) , atomic physics , electric field , line (geometry) , molecular physics , materials science , nuclear physics , geometry , composite material , mathematics , quantum mechanics , metallurgy
Plasma filaments have been observed by reciprocating electric probes in the Scrape-Off Layer (SOL) of the Wendelstein 7-X stellarator. Comparison with target probes indicates that a filament observed in the W7-X SOL extends to the sheath. Two-dimensional simulations of seeded filaments exhibit good quantitative agreement with experimental measurements in filament velocity scalings, despite an assumption of constant field line curvature. Both experiment and simulation show a slow radial propagation of filaments, indicating that filaments are essentially bound to their flux surface and do not perform ballistic radial motion. In contrast, the poloidal propagation along flux surfaces is much faster than the radial motion.