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Title: Promising High-Confinement Regime for Steady-State Fusion

Abstract

A reproducible stationary high-confinement regime with small “edge-localized modes” (ELMs) has been achieved recently in the Experimental Advanced Superconducting Tokamak, which has a metal wall and low plasma rotation as projected for a fusion reactor. Here, we have uncovered that this small ELM regime is enabled by a wide edge transport barrier (pedestal) with a low density gradient and a high density ratio between the pedestal foot and top. Nonlinear simulations reveal, for the first time, that the underlying mechanism for the observed small ELM crashes is the upper movement of the peeling boundary induced by an initial radially localized collapse in the pedestal, which stops the growth of instabilities and further collapse of the pedestal, thus providing a physics basis for mitigating ELMs in future steady-state fusion reactors.

Authors:
 [1];  [2];  [1];  [2];  [3];  [4];  [5];  [1];  [1];  [1];  [6];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Chinese Academy of Sciences, Hefei (China)
  2. Chinese Academy of Sciences, Hefei (China); Univ. of Science and Technology of China, Hefei (China)
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. General Atomics, San Diego, CA (United States)
  5. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  6. Univ. of Science and Technology of China, Hefei (China); General Atomics, San Diego, CA (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
The National Magnetic Confinement Fusion Science Program of China; USDOE
OSTI Identifier:
1532734
Grant/Contract Number:  
AC02-09CH11466
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 122; Journal Issue: 25; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Xu, G. S., Yang, Q. Q., Yan, N., Wang, Y. F., Xu, X. Q., Guo, H. Y., Maingi, R., Wang, L., Qian, J. P., Gong, X. Z., Chan, V. S., Zhang, T., Zang, Q., Li, Y. Y., Zhang, L., Hu, G. H., and Wan, B. N. Promising High-Confinement Regime for Steady-State Fusion. United States: N. p., 2019. Web. doi:10.1103/PhysRevLett.122.255001.
Xu, G. S., Yang, Q. Q., Yan, N., Wang, Y. F., Xu, X. Q., Guo, H. Y., Maingi, R., Wang, L., Qian, J. P., Gong, X. Z., Chan, V. S., Zhang, T., Zang, Q., Li, Y. Y., Zhang, L., Hu, G. H., & Wan, B. N. Promising High-Confinement Regime for Steady-State Fusion. United States. doi:10.1103/PhysRevLett.122.255001.
Xu, G. S., Yang, Q. Q., Yan, N., Wang, Y. F., Xu, X. Q., Guo, H. Y., Maingi, R., Wang, L., Qian, J. P., Gong, X. Z., Chan, V. S., Zhang, T., Zang, Q., Li, Y. Y., Zhang, L., Hu, G. H., and Wan, B. N. Wed . "Promising High-Confinement Regime for Steady-State Fusion". United States. doi:10.1103/PhysRevLett.122.255001. https://www.osti.gov/servlets/purl/1532734.
@article{osti_1532734,
title = {Promising High-Confinement Regime for Steady-State Fusion},
author = {Xu, G. S. and Yang, Q. Q. and Yan, N. and Wang, Y. F. and Xu, X. Q. and Guo, H. Y. and Maingi, R. and Wang, L. and Qian, J. P. and Gong, X. Z. and Chan, V. S. and Zhang, T. and Zang, Q. and Li, Y. Y. and Zhang, L. and Hu, G. H. and Wan, B. N.},
abstractNote = {A reproducible stationary high-confinement regime with small “edge-localized modes” (ELMs) has been achieved recently in the Experimental Advanced Superconducting Tokamak, which has a metal wall and low plasma rotation as projected for a fusion reactor. Here, we have uncovered that this small ELM regime is enabled by a wide edge transport barrier (pedestal) with a low density gradient and a high density ratio between the pedestal foot and top. Nonlinear simulations reveal, for the first time, that the underlying mechanism for the observed small ELM crashes is the upper movement of the peeling boundary induced by an initial radially localized collapse in the pedestal, which stops the growth of instabilities and further collapse of the pedestal, thus providing a physics basis for mitigating ELMs in future steady-state fusion reactors.},
doi = {10.1103/PhysRevLett.122.255001},
journal = {Physical Review Letters},
number = 25,
volume = 122,
place = {United States},
year = {2019},
month = {6}
}

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