Heat-flux footprints for I-mode and EDA H-mode plasmas on Alcator C-Mod

[摘要] IR thermography is used to measure the heat flux footprints on C-Mod's outer target in I-mode and EDA H-mode plasmas. The footprint profiles are fit to a function with a simple physical interpretation. The fit parameter that is sensitive to the power decay length into the SOL, lambda(SOL), is similar to 1-3 x larger in I-modes than in H-modes at similar plasma current, which is the dominant dependence for the H-mode lambda(SOL). In contrast, the fit parameter sensitive to transport into the private-flux-zone along the divertor leg is somewhat smaller in I-mode than in H-mode, but otherwise displays no obvious dependence on I-p, B-t, or stored energy. A third measure of the footprint width, the integral width'', is not significantly different between H- and I-modes. Also discussed are significant differences in the global power flows of the H-modes with favorable'' del B drift direction and those of the I-modes with unfavorable'' del B drift direction. (C) 2013 Elsevier B. V. All rights reserved.

[发布日期] 2013-07-01

[效力级别]  Proceedings Paper