Scaling of the power exhaust channel in Alcator C-Mod
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Hutchinson_Scaling of.pdf
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7.57 MB
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Checksum (MD5)
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Author(s)
Rowan, W. L.
Wurden, G.
Labombard, Brian
Brunner, Daniel Frederic
Payne, Joshua E.
Reinke, Matthew Logan
Cziegler, Istvan
Granetz, Robert S.
Greenwald, Martin J.
Irby, James Henderson
Date Issued
April 2011
Journal
Physics of Plasmas
Publisher
American Institute of Physics
Citation
LaBombard, B. et al. “Scaling of the power exhaust channel in Alcator C-Mod.” Physics of Plasmas 18 (2011): 056104. Web. 9 Dec. 2011. © 2011 American Institute of Physics
Version
Final published version
Abstract
Parametric dependences of the heat flux footprint on the outer divertor target plate are explored in EDA H-mode and ohmic L-mode plasmas over a wide range of parameters with attached plasma conditions. Heat flux profile shapes are found to be independent of toroidal field strength, independent of power flow along magnetic field lines and insensitive to x-point topology (single-null versus double-null). The magnitudes and widths closely follow that of the “upstream” pressure profile, which are correlated to plasma thermal energy content and plasma current. Heat flux decay lengths near the strike-point in H- and L-mode plasmas scale approximately with the inverse of plasma current, with a diminished dependence at high collisionality in L-mode. Consistent with previous studies, pressure gradients in the boundary scale with plasma current squared, holding the magnetohydrodynamic ballooning parameter approximately invariant at fixed collisionality—strong evidence that critical-gradient transport physics plays a key role in setting the power exhaust channel.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1063/1.3566059
