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Title: M3D-C1 simulations of the plasma response to RMPs in NSTX-U single-null and snowflake divertor configurations

Abstract

Non-axisymmetric control coils and the so-called snow ake divertor con guration are two potential solutions proposed to solve two separate outstanding issues on the path towards self-sustained burning plasma operations, namely the transient energy bursts caused by edge localized modes and the steady state heat exhaust problem. In a reactor, these two proposed solutions would have to operate simultaneously and it is, therefore, important to investigate their compatibility and to identify possible con icts that could prevent them from operating simultaneously. In this work, single- and two- uid resistive magnetohydrodynamic calculations are used to investigate the e ect of externally applied n = 3 magnetic perturbations on the snow ake divertor con guration. The calculations are performed using the code M3D-C1 and are based on simulated NSTX-U plasmas. The results show that additional and longer magnetic lobes are created in the null-point region of the snow ake con guration, compared to those in the conventional single-null. The intersection of these longer and additional lobes with the divertor plates are expected to cause more striations in the particle and heat ux target pro les. In addition, the results indicate that the size of the magnetic lobes, in both single-null and snowmore » ake con gurations, are more sensitive to resonant magnetic perturbations than to non-resonant magnetic perturbations. The results also suggest that lower values of current in nonaxisymmetric control coils closer to the null-point region would be required to suppress edge localized modes. This e ect is expected to be enhanced in plasmas with the snow ake con guration.« less

Authors:
 [1];  [2];  [3];  [3];  [2];  [4];  [2];  [4];  [5];  [6];  [6];  [7];  [6];  [8]
  1. General Atomics, San Diego, CA (United States); Oak Ridge Associated Univ., Oak Ridge, TN (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Univ. of Sao Paulo (Brazil). Dept. of Applied Physics
  6. Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics
  7. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  8. Columbia Univ., New York, NY (United States). Dept. of Applied Physics and Applied Mathematics
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1373377
Alternate Identifier(s):
OSTI ID: 1374813; OSTI ID: 1376338; OSTI ID: 1771442
Report Number(s):
LLNL-JRNL-820478
Journal ID: ISSN 0029-5515
Grant/Contract Number:  
SC0012706; FC02-04ER54698; AC05-06OR23100; AC02-09CH11466; AC05-00OR22725; SC0012315; SC0013911; AC52-07NA27344; SC0008520
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 57; Journal Issue: 7; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; snowflake divertor; RMP; plasma response; two-fluid MHD

Citation Formats

Canal, G. P., Ferraro, N. M., Evans, T. E., Osborne, T. H., Menard, J. E., Ahn, J. -W., Maingi, R., Wingen, A., Ciro, D., Frerichs, H., Schmitz, O., Soukhanoviskii, V., Waters, I., and Sabbagh, S. A.. M3D-C1 simulations of the plasma response to RMPs in NSTX-U single-null and snowflake divertor configurations. United States: N. p., 2017. Web. https://doi.org/10.1088/1741-4326/aa6e10.
Canal, G. P., Ferraro, N. M., Evans, T. E., Osborne, T. H., Menard, J. E., Ahn, J. -W., Maingi, R., Wingen, A., Ciro, D., Frerichs, H., Schmitz, O., Soukhanoviskii, V., Waters, I., & Sabbagh, S. A.. M3D-C1 simulations of the plasma response to RMPs in NSTX-U single-null and snowflake divertor configurations. United States. https://doi.org/10.1088/1741-4326/aa6e10
Canal, G. P., Ferraro, N. M., Evans, T. E., Osborne, T. H., Menard, J. E., Ahn, J. -W., Maingi, R., Wingen, A., Ciro, D., Frerichs, H., Schmitz, O., Soukhanoviskii, V., Waters, I., and Sabbagh, S. A.. Thu . "M3D-C1 simulations of the plasma response to RMPs in NSTX-U single-null and snowflake divertor configurations". United States. https://doi.org/10.1088/1741-4326/aa6e10. https://www.osti.gov/servlets/purl/1373377.
@article{osti_1373377,
title = {M3D-C1 simulations of the plasma response to RMPs in NSTX-U single-null and snowflake divertor configurations},
author = {Canal, G. P. and Ferraro, N. M. and Evans, T. E. and Osborne, T. H. and Menard, J. E. and Ahn, J. -W. and Maingi, R. and Wingen, A. and Ciro, D. and Frerichs, H. and Schmitz, O. and Soukhanoviskii, V. and Waters, I. and Sabbagh, S. A.},
abstractNote = {Non-axisymmetric control coils and the so-called snow ake divertor con guration are two potential solutions proposed to solve two separate outstanding issues on the path towards self-sustained burning plasma operations, namely the transient energy bursts caused by edge localized modes and the steady state heat exhaust problem. In a reactor, these two proposed solutions would have to operate simultaneously and it is, therefore, important to investigate their compatibility and to identify possible con icts that could prevent them from operating simultaneously. In this work, single- and two- uid resistive magnetohydrodynamic calculations are used to investigate the e ect of externally applied n = 3 magnetic perturbations on the snow ake divertor con guration. The calculations are performed using the code M3D-C1 and are based on simulated NSTX-U plasmas. The results show that additional and longer magnetic lobes are created in the null-point region of the snow ake con guration, compared to those in the conventional single-null. The intersection of these longer and additional lobes with the divertor plates are expected to cause more striations in the particle and heat ux target pro les. In addition, the results indicate that the size of the magnetic lobes, in both single-null and snow ake con gurations, are more sensitive to resonant magnetic perturbations than to non-resonant magnetic perturbations. The results also suggest that lower values of current in nonaxisymmetric control coils closer to the null-point region would be required to suppress edge localized modes. This e ect is expected to be enhanced in plasmas with the snow ake con guration.},
doi = {10.1088/1741-4326/aa6e10},
journal = {Nuclear Fusion},
number = 7,
volume = 57,
place = {United States},
year = {2017},
month = {4}
}

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