Blob sizes and velocities in the Alcator C-Mod scrape-off layer

[摘要] Gas-puff imaging data is used to investigate the dynamics of blob-like structures in the scrape-off layer of Alcator C-Mod. A blob-tracking algorithm is developed and used to compute blob propagation velocities and cross-field sizes for a series of discharges where the line-averaged particle density ne is varied. We find that the mean radial blob velocity increases from 150 ms(-1) for (n) over bar (e)= n(G) = 0: 15 to 450 ms(-1) for (N) over bar (e)= n(G) = 0: 48, where is the nG the Greenwald density. The cross-field size of the blobs is independent of the line-averaged particle densities. With increasing ne= nG the observed blob velocities become larger than predicted by simple blob models for sheath-connected plasma filaments. (C) 2013 Elsevier B.V. All rights reserved.

[发布日期] 2013-07-01

[效力级别]  Proceedings Paper