High-β steady-state scenarios in DIII-D with on-axis current drive

C. C. Petty; J. R. Ferron; F. Turco; J. M. Park; A. M. Garofalo; A. W. Hyatt; G. L. Jackson; T. C. Luce; C. T. Holcomb; E. J. Doyle; W. M. Solomon

High-β steady-state scenarios in DIII-D with on-axis current drive

C. C. Petty, J. R. Ferron, F. Turco, J. M. Park, A. M. Garofalo, A. W. Hyatt, G. L. Jackson, T. C. Luce, C. T. Holcomb, E. J. Doyle, W. M. Solomon

Plasma Theory and Modeling

Research output: Contribution to conference › Paper › peer-review

Abstract

Experiments in the DIII-D tokamak have demonstrated potential new paths to fusion steady state based on peaked current profiles with q_min≈1 that have high ideal stability limits, excellent confinement and benefit from efficient on-axis current drive. In the hybrid scenario, steady-state conditions (V_surf=0) using central ECCD and NBCD are achieved in 1.0 MA discharges with a beta value (β_N=3.6) that is 80%-90% of the ideal n=1 with-wall limit. Interestingly, the hybrid mechanism that anomalously broadens the current profile to maintain q_min>1 and prevents sawteeth continues to function despite the intense central current drive. In the "high ℓ_i" scenario, the combination of broad pressure profile and a peaked current profile tailored to maximize ℓ_i allows β_N≈4.8 and H_98y2≈1.8 to be achieved transiently in a discharge that is overdriven (V_surf<0). The achieved β_N is near the no-wall limit with the idealwall limit higher at β_N≈5-6.

Original language	English
State	Published - 2015
Event	42nd European Physical Society Conference on Plasma Physics, EPS 2015 - Lisbon, Portugal Duration: Jun 22 2015 → Jun 26 2015

Conference

Conference	42nd European Physical Society Conference on Plasma Physics, EPS 2015
Country/Territory	Portugal
City	Lisbon
Period	06/22/15 → 06/26/15

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Cite this

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title = "High-β steady-state scenarios in DIII-D with on-axis current drive",

abstract = "Experiments in the DIII-D tokamak have demonstrated potential new paths to fusion steady state based on peaked current profiles with qmin≈1 that have high ideal stability limits, excellent confinement and benefit from efficient on-axis current drive. In the hybrid scenario, steady-state conditions (Vsurf=0) using central ECCD and NBCD are achieved in 1.0 MA discharges with a beta value (βN=3.6) that is 80%-90% of the ideal n=1 with-wall limit. Interestingly, the hybrid mechanism that anomalously broadens the current profile to maintain qmin>1 and prevents sawteeth continues to function despite the intense central current drive. In the {"}high ℓi{"} scenario, the combination of broad pressure profile and a peaked current profile tailored to maximize ℓi allows βN≈4.8 and H98y2≈1.8 to be achieved transiently in a discharge that is overdriven (Vsurf<0). The achieved βN is near the no-wall limit with the idealwall limit higher at βN≈5-6.",

author = "Petty, {C. C.} and Ferron, {J. R.} and F. Turco and Park, {J. M.} and Garofalo, {A. M.} and Hyatt, {A. W.} and Jackson, {G. L.} and Luce, {T. C.} and Holcomb, {C. T.} and Doyle, {E. J.} and Solomon, {W. M.}",

year = "2015",

language = "English",

note = "42nd European Physical Society Conference on Plasma Physics, EPS 2015 ; Conference date: 22-06-2015 Through 26-06-2015",

}

TY - CONF

T1 - High-β steady-state scenarios in DIII-D with on-axis current drive

AU - Petty, C. C.

AU - Ferron, J. R.

AU - Turco, F.

AU - Park, J. M.

AU - Garofalo, A. M.

AU - Hyatt, A. W.

AU - Jackson, G. L.

AU - Luce, T. C.

AU - Holcomb, C. T.

AU - Doyle, E. J.

AU - Solomon, W. M.

PY - 2015

Y1 - 2015

N2 - Experiments in the DIII-D tokamak have demonstrated potential new paths to fusion steady state based on peaked current profiles with qmin≈1 that have high ideal stability limits, excellent confinement and benefit from efficient on-axis current drive. In the hybrid scenario, steady-state conditions (Vsurf=0) using central ECCD and NBCD are achieved in 1.0 MA discharges with a beta value (βN=3.6) that is 80%-90% of the ideal n=1 with-wall limit. Interestingly, the hybrid mechanism that anomalously broadens the current profile to maintain qmin>1 and prevents sawteeth continues to function despite the intense central current drive. In the "high ℓi" scenario, the combination of broad pressure profile and a peaked current profile tailored to maximize ℓi allows βN≈4.8 and H98y2≈1.8 to be achieved transiently in a discharge that is overdriven (Vsurf<0). The achieved βN is near the no-wall limit with the idealwall limit higher at βN≈5-6.

AB - Experiments in the DIII-D tokamak have demonstrated potential new paths to fusion steady state based on peaked current profiles with qmin≈1 that have high ideal stability limits, excellent confinement and benefit from efficient on-axis current drive. In the hybrid scenario, steady-state conditions (Vsurf=0) using central ECCD and NBCD are achieved in 1.0 MA discharges with a beta value (βN=3.6) that is 80%-90% of the ideal n=1 with-wall limit. Interestingly, the hybrid mechanism that anomalously broadens the current profile to maintain qmin>1 and prevents sawteeth continues to function despite the intense central current drive. In the "high ℓi" scenario, the combination of broad pressure profile and a peaked current profile tailored to maximize ℓi allows βN≈4.8 and H98y2≈1.8 to be achieved transiently in a discharge that is overdriven (Vsurf<0). The achieved βN is near the no-wall limit with the idealwall limit higher at βN≈5-6.

UR - http://www.scopus.com/inward/record.url?scp=84979710730&partnerID=8YFLogxK

M3 - Paper

AN - SCOPUS:84979710730

T2 - 42nd European Physical Society Conference on Plasma Physics, EPS 2015

Y2 - 22 June 2015 through 26 June 2015

ER -

High-β steady-state scenarios in DIII-D with on-axis current drive

Abstract

Conference

UN SDGs

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