The physics mechanisms of the weakly coherent mode in the Alcator C-Mod Tokamak

The weakly coherent mode (WCM) in I-mode has been studied by a six-field two-fluid model based on the Braginskii equations under the BOUT++ framework for the first time. The calculations indicate that a tokamak pedestal exhibiting a WCM is linearly unstable to drift Alfven wave (DAW) instabilities a...

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Main Authors: Liu, Z. X. (Author), Xu, X. Q. (Author), Gao, X. (Author), Xia, T. Y. (Author), Zhang, T. (Author), Li, J. G. (Author), Hubbard, Amanda E (Contributor), Hughes Jr, Jerry (Contributor), Walk Jr, John R (Contributor), Theiler, Christian (Contributor), Baek, Seung Gyou (Contributor), Golfinopoulos, Theodore (Contributor), Whyte, Dennis G (Contributor)
Other Authors: Massachusetts Institute of Technology. Plasma Science and Fusion Center (Contributor)
Format: Article
Language:English
Published: AIP Publishing, 2018-07-25T18:12:59Z.
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Online Access:Get fulltext
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100 1 0 |a Liu, Z. X.  |e author 
100 1 0 |a Massachusetts Institute of Technology. Plasma Science and Fusion Center  |e contributor 
100 1 0 |a Hubbard, Amanda E  |e contributor 
100 1 0 |a Hughes Jr, Jerry  |e contributor 
100 1 0 |a Walk Jr, John R  |e contributor 
100 1 0 |a Theiler, Christian  |e contributor 
100 1 0 |a Baek, Seung Gyou  |e contributor 
100 1 0 |a Golfinopoulos, Theodore  |e contributor 
100 1 0 |a Whyte, Dennis G  |e contributor 
700 1 0 |a Xu, X. Q.  |e author 
700 1 0 |a Gao, X.  |e author 
700 1 0 |a Xia, T. Y.  |e author 
700 1 0 |a Zhang, T.  |e author 
700 1 0 |a Li, J. G.  |e author 
700 1 0 |a Hubbard, Amanda E  |e author 
700 1 0 |a Hughes Jr, Jerry  |e author 
700 1 0 |a Walk Jr, John R  |e author 
700 1 0 |a Theiler, Christian  |e author 
700 1 0 |a Baek, Seung Gyou  |e author 
700 1 0 |a Golfinopoulos, Theodore  |e author 
700 1 0 |a Whyte, Dennis G  |e author 
245 0 0 |a The physics mechanisms of the weakly coherent mode in the Alcator C-Mod Tokamak 
260 |b AIP Publishing,   |c 2018-07-25T18:12:59Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/117124 
520 |a The weakly coherent mode (WCM) in I-mode has been studied by a six-field two-fluid model based on the Braginskii equations under the BOUT++ framework for the first time. The calculations indicate that a tokamak pedestal exhibiting a WCM is linearly unstable to drift Alfven wave (DAW) instabilities and the resistive ballooning mode. The nonlinear simulation shows promising agreement with the experimental measurements of the WCM. The shape of the density spectral and location of the spectral peak of the dominant toroidal number mode n = 20 agrees with the experimental data from reflectometry. The simulated mode propagates in electron diamagnetic direction is consistent with the results from the magnetic probes in the laboratory frame, a large ratio of particle to heat diffusivity is consistent with the distinctive experimental feature of I-mode, and the value of the simulated χeat the edge is in the range of experimental errors of χefffrom the experiment. The prediction of the WCM shows that free energy is mainly provided by the electron pressure gradient, which gives guidance for pursuing future I-mode studies. 
655 7 |a Article 
773 |t Physics of Plasmas