β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas

J. E. Menard; M. G. Bell; R. E. Bell; E. D. Fredrickson; D. A. Gates; S. M. Kaye; B. P. LeBlanc; R. Maingi; D. Mueller; S. A. Sabbagh; D. Stutman; C. E. Bush; D. W. Johnson; R. Kaita; H. W. Kugel; R. J. Maqueda; F. Paoletti; S. F. Paul; M. Ono; Y. K.M. Peng; C. H. Skinner; E. J. Synakowski

doi:10.1088/0029-5515/43/5/305

β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas

J. E. Menard
, M. G. Bell
, R. E. Bell
, E. D. Fredrickson
, D. A. Gates
, S. M. Kaye
, B. P. LeBlanc
, R. Maingi
, D. Mueller
, S. A. Sabbagh
, D. Stutman
, C. E. Bush
, D. W. Johnson
, R. Kaita
, H. W. Kugel
, R. J. Maqueda
, F. Paoletti
, S. F. Paul
, M. Ono
, Y. K.M. Peng

C. H. Skinner, E. J. Synakowski

Department of Physics

Research output: Contribution to journal › Article › peer-review

84 Scopus citations

Abstract

Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access to higher normalized β and lower internal inductance. Second, the correction of a poloidal field coil induced error-field has largely eliminated locked tearing modes during normal operation and increased the maximum achievable β. As a result of these improvements, peak β values have reached (not simultaneously) β_T = 35%, β_N = 6.4, (β_N) = 4.5, β_N/l_i = 10, and β_P = 1.4. High β_P operation with reduced tearing activity has allowed a doubling of discharge pulse-length to just over 1 s with sustained periods of β_N ≈ 6 above the ideal no-wall limit and near the with-wall limit. Details of the β-limit scalings and β-limiting instabilities in various operating regimes are described.

Original language	English
Pages (from-to)	330-340
Number of pages	11
Journal	Nuclear Fusion
Volume	43
Issue number	5
DOIs	https://doi.org/10.1088/0029-5515/43/5/305
State	Published - May 2003

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Menard, J. E., Bell, M. G., Bell, R. E., Fredrickson, E. D., Gates, D. A., Kaye, S. M., LeBlanc, B. P., Maingi, R., Mueller, D., Sabbagh, S. A., Stutman, D., Bush, C. E., Johnson, D. W., Kaita, R., Kugel, H. W., Maqueda, R. J., Paoletti, F., Paul, S. F., Ono, M., ... Synakowski, E. J. (2003). β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas. Nuclear Fusion, 43(5), 330-340. https://doi.org/10.1088/0029-5515/43/5/305

@article{e031737bd3c74fa98f94dd1992a066cb,

title = "β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas",

abstract = "Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access to higher normalized β and lower internal inductance. Second, the correction of a poloidal field coil induced error-field has largely eliminated locked tearing modes during normal operation and increased the maximum achievable β. As a result of these improvements, peak β values have reached (not simultaneously) βT = 35\%, βN = 6.4, (βN) = 4.5, βN/li = 10, and βP = 1.4. High βP operation with reduced tearing activity has allowed a doubling of discharge pulse-length to just over 1 s with sustained periods of βN ≈ 6 above the ideal no-wall limit and near the with-wall limit. Details of the β-limit scalings and β-limiting instabilities in various operating regimes are described.",

author = "Menard, \{J. E.\} and Bell, \{M. G.\} and Bell, \{R. E.\} and Fredrickson, \{E. D.\} and Gates, \{D. A.\} and Kaye, \{S. M.\} and LeBlanc, \{B. P.\} and R. Maingi and D. Mueller and Sabbagh, \{S. A.\} and D. Stutman and Bush, \{C. E.\} and Johnson, \{D. W.\} and R. Kaita and Kugel, \{H. W.\} and Maqueda, \{R. J.\} and F. Paoletti and Paul, \{S. F.\} and M. Ono and Peng, \{Y. K.M.\} and Skinner, \{C. H.\} and Synakowski, \{E. J.\}",

year = "2003",

month = may,

doi = "10.1088/0029-5515/43/5/305",

language = "English",

volume = "43",

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}

Menard, JE, Bell, MG, Bell, RE, Fredrickson, ED, Gates, DA, Kaye, SM, LeBlanc, BP, Maingi, R, Mueller, D, Sabbagh, SA, Stutman, D, Bush, CE, Johnson, DW, Kaita, R, Kugel, HW, Maqueda, RJ, Paoletti, F, Paul, SF, Ono, M, Peng, YKM, Skinner, CH & Synakowski, EJ 2003, 'β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas', Nuclear Fusion, vol. 43, no. 5, pp. 330-340. https://doi.org/10.1088/0029-5515/43/5/305

TY - JOUR

T1 - β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas

AU - Menard, J. E.

AU - Bell, M. G.

AU - Bell, R. E.

AU - Fredrickson, E. D.

AU - Gates, D. A.

AU - Kaye, S. M.

AU - LeBlanc, B. P.

AU - Maingi, R.

AU - Mueller, D.

AU - Sabbagh, S. A.

AU - Stutman, D.

AU - Bush, C. E.

AU - Johnson, D. W.

AU - Kaita, R.

AU - Kugel, H. W.

AU - Maqueda, R. J.

AU - Paoletti, F.

AU - Paul, S. F.

AU - Ono, M.

AU - Peng, Y. K.M.

AU - Skinner, C. H.

AU - Synakowski, E. J.

PY - 2003/5

Y1 - 2003/5

N2 - Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access to higher normalized β and lower internal inductance. Second, the correction of a poloidal field coil induced error-field has largely eliminated locked tearing modes during normal operation and increased the maximum achievable β. As a result of these improvements, peak β values have reached (not simultaneously) βT = 35%, βN = 6.4, (βN) = 4.5, βN/li = 10, and βP = 1.4. High βP operation with reduced tearing activity has allowed a doubling of discharge pulse-length to just over 1 s with sustained periods of βN ≈ 6 above the ideal no-wall limit and near the with-wall limit. Details of the β-limit scalings and β-limiting instabilities in various operating regimes are described.

AB - Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access to higher normalized β and lower internal inductance. Second, the correction of a poloidal field coil induced error-field has largely eliminated locked tearing modes during normal operation and increased the maximum achievable β. As a result of these improvements, peak β values have reached (not simultaneously) βT = 35%, βN = 6.4, (βN) = 4.5, βN/li = 10, and βP = 1.4. High βP operation with reduced tearing activity has allowed a doubling of discharge pulse-length to just over 1 s with sustained periods of βN ≈ 6 above the ideal no-wall limit and near the with-wall limit. Details of the β-limit scalings and β-limiting instabilities in various operating regimes are described.

UR - https://www.scopus.com/pages/publications/0037872769

UR - https://www.scopus.com/pages/publications/0037872769#tab=citedBy

U2 - 10.1088/0029-5515/43/5/305

DO - 10.1088/0029-5515/43/5/305

M3 - Article

AN - SCOPUS:0037872769

SN - 0029-5515

VL - 43

SP - 330

EP - 340

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 5

ER -

β-limiting MHD instabilities in improved-performance NSTX spherical torus plasmas

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