Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas

doi:10.1088/1741-4326/aaf671

Title: Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas

Abstract

Here, the successful application of three-dimensional (3D) magnetohydrodynamic (MHD) spectroscopy in the stable DIII-D and EAST plasmas enables to directly extract the multi-mode plasma transfer function in tokamak experiments. The transfer function not only reveals the contribution of each dominant MHD eigenmode in the multi-model plasma response, but also quantifies the corresponding eigenvalue which is the critical stability index of MHD mode. The method performs the active detection of stable plasma by utilizing the upper and lower rows of internal coils to scan the frequency and poloidal spectrum of the applied 3D field, and reconstructing the multi-mode transfer functions model through the least square fitting of the plasma response measured by 3D-field magnetic sensors distributed at different poloidal locations. The results point to the potential development of an advanced strategy for tracking the plasma stability based on the extracted eigenvalues of stable modes. The improved understanding of the dominant eigenmodes' behavior in multi-mode plasma response through transfer function can also help to optimize the applied 3D fields for the purposes, such as the type-I edge localized mode suppression and the core stability control in future fusion reactors.

Authors:

Wang, Z. R. ^[1]; Logan, N. C. ^[1]; Munaretto, S. ^[2]; Liu, Y. Q. ^[2]; Sun, Y. W. ^[3]; Gu, S. ^[3]; Park, J. -K. ^[1]; Hanson, J. M. ^[4]; Hu, Q. M. ^[1]; Strait, T. ^[2]; Nazikian, R. ^[1]; Kolemen, E. ^[1]; Menard, J. E. ^[1]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
General Atomics, San Diego, CA (United States)
Chinese Academy of Sciences, Hefei (China)
Columbia Univ., New York, NY (United States)

Publication Date:: 2018-01-09

Research Org.:: General Atomics, San Diego, CA (United States); Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE

Contributing Org.:: This work is also supported by the National Natural Science Foundation of China under 11475224.

OSTI Identifier:: 1477873

Alternate Identifier(s):: OSTI ID: 1558405

Grant/Contract Number:: FC02-04ER54698; AC02-09CH11466

Resource Type:: Journal Article: Accepted Manuscript

Journal Name:: Nuclear Fusion

Additional Journal Information:: Journal Volume: 59; Journal Issue: 2; Journal ID: ISSN 0029-5515

Publisher:: IOP Science

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 3D MHD spectroscopy; transfer function; plasma response; plasma stability

Citation Formats


                    Wang, Z. R., Logan, N. C., Munaretto, S., Liu, Y. Q., Sun, Y. W., Gu, S., Park, J. -K., Hanson, J. M., Hu, Q. M., Strait, T., Nazikian, R., Kolemen, E., and Menard, J. E. Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas.  United States: N. p., 2018. 
        Web.  doi:10.1088/1741-4326/aaf671.

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                    Wang, Z. R., Logan, N. C., Munaretto, S., Liu, Y. Q., Sun, Y. W., Gu, S., Park, J. -K., Hanson, J. M., Hu, Q. M., Strait, T., Nazikian, R., Kolemen, E., & Menard, J. E. Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas.  United States.  doi:10.1088/1741-4326/aaf671.

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                    Wang, Z. R., Logan, N. C., Munaretto, S., Liu, Y. Q., Sun, Y. W., Gu, S., Park, J. -K., Hanson, J. M., Hu, Q. M., Strait, T., Nazikian, R., Kolemen, E., and Menard, J. E. Tue .  
        "Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas".  United States.  doi:10.1088/1741-4326/aaf671.  https://www.osti.gov/servlets/purl/1477873.

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@article{osti_1477873,

  title        = {Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas},

  author       = {Wang, Z. R. and Logan, N. C. and Munaretto, S. and Liu, Y. Q. and Sun, Y. W. and Gu, S. and Park, J. -K. and Hanson, J. M. and Hu, Q. M. and Strait, T. and Nazikian, R. and Kolemen, E. and Menard, J. E.},

  abstractNote = {Here, the successful application of three-dimensional (3D) magnetohydrodynamic (MHD) spectroscopy in the stable DIII-D and EAST plasmas enables to directly extract the multi-mode plasma transfer function in tokamak experiments. The transfer function not only reveals the contribution of each dominant MHD eigenmode in the multi-model plasma response, but also quantifies the corresponding eigenvalue which is the critical stability index of MHD mode. The method performs the active detection of stable plasma by utilizing the upper and lower rows of internal coils to scan the frequency and poloidal spectrum of the applied 3D field, and reconstructing the multi-mode transfer functions model through the least square fitting of the plasma response measured by 3D-field magnetic sensors distributed at different poloidal locations. The results point to the potential development of an advanced strategy for tracking the plasma stability based on the extracted eigenvalues of stable modes. The improved understanding of the dominant eigenmodes' behavior in multi-mode plasma response through transfer function can also help to optimize the applied 3D fields for the purposes, such as the type-I edge localized mode suppression and the core stability control in future fusion reactors.},

  doi          = {10.1088/1741-4326/aaf671},

  journal      = {Nuclear Fusion},

  issn         = {0029-5515},

  number       = 2,

  volume       = 59,

  place        = {United States},

  year         = {2018},

  month        = {1}

}

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DOI: 10.1088/1741-4326/aaf671

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Figures / Tables:

FIG. 1: Time evolution of discharge 170220. The steady flattop I_p, β_N and q₉₅ are shown in (a). The wave form of applied current represented in (b) drives the n = 1 magnetic response (c) measured by a radial sensor array located near the mid-plane of the HFS vessel wall.

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