Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9793858 | Journal of Nuclear Materials | 2005 | 5 Pages |
Abstract
A novel, magnetically-driven swing probe was recently installed near the midplane on the high-field side SOL in Alcator C-Mod. The probe collects plasma from co- and counter-current directions during its respective 0-90° and 90-180° of motion, thus providing profiles of density, electron temperature and plasma flow parallel to magnetic field lines (Mach number, Mâ¥) up to the separatrix. Results are reported from discharges with different magnetic topologies: lower single-null, upper single-null, and double-null. In single-null, a strong parallel flow (â£Mâ¥â£Â â¼Â 1) is detected, which is always directed from the low- to high-field SOL. In double-null discharges, e-folding lengths in the high-field SOL are a factor of â¼4 shorter than the low-field SOL. Thus, plasma appears to 'fill-in' the high-field SOL in single-null plasmas, not by cross-field transport but by parallel flow from the low-field SOL - a picture consistent with a very strong ballooning-like component to the cross-field transport.
Related Topics
Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
N. Smick, B. LaBombard, C.S. Pitcher,