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Title: Edge state selection by modulating E × B shearing profile in toroidally confined plasmas

Abstract

We investigate how the E × B shearing profile impacts the energy transport induced by the MHD mode in the edge of H-mode plasmas. By enhancing the outer layer (ψ nor ≈ 0.9–1) shear, the growth rate spectrum γ(n) gets narrowed with the fastest growth rate having a lower toroidal mode number. In the nonlinear stage, the MHD fluctuations tend to reach a coherent, oscillating state, which is analogous to a quiescent (Q) H mode state with edge-harmonic-oscillations. By enhancing the inner layer (ψ nor ≈ 0.7–0.8) shear, γ(n) shifts to lower n, and its width does not change much. In the nonlinear stage, the edge fluctuations tend to stay in an incoherent, oscillating state, which is analogous to a turbulent QH-mode state. Here, we also explore the underlying physics of the results and show that they are closely related to the different cross-phase dynamics of the edge MHD fluctuations induced by the variation of the edge E × B shearing profile.

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2];  [1]
  1. Peking Univ., Beijing (China)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1566001
Alternate Identifier(s):
OSTI ID: 1513056
Report Number(s):
LLNL-JRNL-759659
Journal ID: ISSN 1070-664X; 948107
Grant/Contract Number:  
AC52-07NA27344; LLNL-JRNL-759659
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 26; Journal Issue: 5; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Zhang, Y., Guo, Z. B., Xu, X. Q., and Chen, J. G. Edge state selection by modulating E × B shearing profile in toroidally confined plasmas. United States: N. p., 2019. Web. doi:10.1063/1.5093773.
Zhang, Y., Guo, Z. B., Xu, X. Q., & Chen, J. G. Edge state selection by modulating E × B shearing profile in toroidally confined plasmas. United States. doi:10.1063/1.5093773.
Zhang, Y., Guo, Z. B., Xu, X. Q., and Chen, J. G. Thu . "Edge state selection by modulating E × B shearing profile in toroidally confined plasmas". United States. doi:10.1063/1.5093773.
@article{osti_1566001,
title = {Edge state selection by modulating E × B shearing profile in toroidally confined plasmas},
author = {Zhang, Y. and Guo, Z. B. and Xu, X. Q. and Chen, J. G.},
abstractNote = {We investigate how the E × B shearing profile impacts the energy transport induced by the MHD mode in the edge of H-mode plasmas. By enhancing the outer layer (ψnor ≈ 0.9–1) shear, the growth rate spectrum γ(n) gets narrowed with the fastest growth rate having a lower toroidal mode number. In the nonlinear stage, the MHD fluctuations tend to reach a coherent, oscillating state, which is analogous to a quiescent (Q) H mode state with edge-harmonic-oscillations. By enhancing the inner layer (ψnor ≈ 0.7–0.8) shear, γ(n) shifts to lower n, and its width does not change much. In the nonlinear stage, the edge fluctuations tend to stay in an incoherent, oscillating state, which is analogous to a turbulent QH-mode state. Here, we also explore the underlying physics of the results and show that they are closely related to the different cross-phase dynamics of the edge MHD fluctuations induced by the variation of the edge E × B shearing profile.},
doi = {10.1063/1.5093773},
journal = {Physics of Plasmas},
number = 5,
volume = 26,
place = {United States},
year = {2019},
month = {5}
}

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