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Title: Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak]

Abstract

We report the first observation of increased edge electron temperature turbulence correlated with changes in gradients and the ELM suppression time which occurs after the application of resonant magnetic perturbations (RMP) on DIII-D H-mode plasmas. This increase (T ~ e/T e approximately doubles) occurs in the region extending from the top of the pedestal outward to the upper part of the edge steep gradient region. This is significant as it is consistent with increased turbulence driven transport potentially replacing some part of the edge localized mode (ELM) driven transport. However, temperature turbulence does not change with the initial RMP application while ELMs are still present, indicating the turbulence changes are not causative in the development of ELM suppression or initial profile evolution with RMP – but rather a response to these effects. This temperature turbulence is broadband and long wavelength, k θρ s < 0.5, where k θ = poloidal wavenumber, ρ s = ion sound gyroradius. As has been reported previously, long wavelength density turbulence (k θρ s < 1.0) in the same location also increases after ELMs were suppressed by the RMP. Since the decrease of the density starts nearly immediately with RMP application, these results suggest thatmore » the so-called RMP “density pump-out” is not linked to these long wavelength turbulent transport changes. Comparison with linear stability analysis finds both consistencies and inconsistencies in this important region.« less

Authors:
 [1];  [1];  [1]; ORCiD logo [2];  [2];  [3];  [4];  [4];  [2];  [5];  [1];  [1]; ORCiD logo [2]
  1. Univ. of California, Los Angeles, CA (United States)
  2. General Atomics, San Diego, CA (United States)
  3. National Institutes for Quantum and Radiological Science and Technology, Chiba (Japan)
  4. Univ. of Wisconsin, Madison, WI (United States)
  5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1409224
Alternate Identifier(s):
OSTI ID: 1420641
Grant/Contract Number:
FC02-04ER54698; FG02-08ER54984
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 11; 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

Sung, Choongki, Wang, G., Rhodes, Terry L., Smith, Sterling P., Osborne, Thomas H., Ono, Makoto, McKee, George R., Yan, Zheng, Groebner, Richard J., Davis, Evan M., Zeng, Lei, Peebles, Williams A., and Evans, Todd E. Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak]. United States: N. p., 2017. Web. doi:10.1063/1.4999785.
Sung, Choongki, Wang, G., Rhodes, Terry L., Smith, Sterling P., Osborne, Thomas H., Ono, Makoto, McKee, George R., Yan, Zheng, Groebner, Richard J., Davis, Evan M., Zeng, Lei, Peebles, Williams A., & Evans, Todd E. Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak]. United States. doi:10.1063/1.4999785.
Sung, Choongki, Wang, G., Rhodes, Terry L., Smith, Sterling P., Osborne, Thomas H., Ono, Makoto, McKee, George R., Yan, Zheng, Groebner, Richard J., Davis, Evan M., Zeng, Lei, Peebles, Williams A., and Evans, Todd E. Thu . "Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak]". United States. doi:10.1063/1.4999785.
@article{osti_1409224,
title = {Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak]},
author = {Sung, Choongki and Wang, G. and Rhodes, Terry L. and Smith, Sterling P. and Osborne, Thomas H. and Ono, Makoto and McKee, George R. and Yan, Zheng and Groebner, Richard J. and Davis, Evan M. and Zeng, Lei and Peebles, Williams A. and Evans, Todd E.},
abstractNote = {We report the first observation of increased edge electron temperature turbulence correlated with changes in gradients and the ELM suppression time which occurs after the application of resonant magnetic perturbations (RMP) on DIII-D H-mode plasmas. This increase (T~e/Te approximately doubles) occurs in the region extending from the top of the pedestal outward to the upper part of the edge steep gradient region. This is significant as it is consistent with increased turbulence driven transport potentially replacing some part of the edge localized mode (ELM) driven transport. However, temperature turbulence does not change with the initial RMP application while ELMs are still present, indicating the turbulence changes are not causative in the development of ELM suppression or initial profile evolution with RMP – but rather a response to these effects. This temperature turbulence is broadband and long wavelength, kθρs < 0.5, where kθ = poloidal wavenumber, ρs = ion sound gyroradius. As has been reported previously, long wavelength density turbulence (kθρs < 1.0) in the same location also increases after ELMs were suppressed by the RMP. Since the decrease of the density starts nearly immediately with RMP application, these results suggest that the so-called RMP “density pump-out” is not linked to these long wavelength turbulent transport changes. Comparison with linear stability analysis finds both consistencies and inconsistencies in this important region.},
doi = {10.1063/1.4999785},
journal = {Physics of Plasmas},
number = 11,
volume = 24,
place = {United States},
year = {Thu Nov 16 00:00:00 EST 2017},
month = {Thu Nov 16 00:00:00 EST 2017}
}

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