Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

A. M. Garofalo; X. Gong; B. A. Grierson; Q. Ren; W. M. Solomon; E. J. Strait; M. A. Van Zeeland; C. T. Holcomb; O. Meneghini; S. P. Smith; G. M. Staebler; B. Wan; R. Bravenec; R. V. Budny; S. Ding; J. M. Hanson; W. W. Heidbrink; L. L. Lao; G. Li; C. Pan; C. C. Petty; J. Qian; C. Paz-Soldan; G. Xu

doi:10.1088/0029-5515/55/12/123025

Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

A. M. Garofalo, X. Gong, B. A. Grierson, Q. Ren, W. M. Solomon, E. J. Strait, M. A. Van Zeeland, C. T. Holcomb, O. Meneghini, S. P. Smith, G. M. Staebler, B. Wan, R. Bravenec, R. V. Budny, S. Ding, J. M. Hanson, W. W. Heidbrink, L. L. Lao, G. Li, C. PanC. C. Petty, J. Qian, C. Paz-Soldan, G. Xu

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

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Abstract

Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by 30% relative to earlier work (Politzer et al 2005 Nucl. Fusion 45 417). The advancement was enabled by improved understanding of the 'relaxation oscillations', previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the 'relaxation oscillations' are coupled core-edge modes amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced to classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥80%, β_N ≤ 4, β_P ≥ 3, and β_T ≥ 2%. These results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.

Original language	English
Article number	123025
Journal	Nuclear Fusion
Volume	55
Issue number	12
DOIs	https://doi.org/10.1088/0029-5515/55/12/123025
State	Published - Nov 16 2015
Externally published	Yes

Funding

Funders	Funder number
U.S. Department of Energy	DE-FG02-04ER54761, DE-AC02-09CH11466, DE-FC02-04ER54698, DE-AC52-07NA27344, SC-G903402

Keywords

high beta
ion transport barrier
steady state
wall stabilization

UN SDGs

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

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10.1088/0029-5515/55/12/123025

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Garofalo, A. M., Gong, X., Grierson, B. A., Ren, Q., Solomon, W. M., Strait, E. J., Van Zeeland, M. A., Holcomb, C. T., Meneghini, O., Smith, S. P., Staebler, G. M., Wan, B., Bravenec, R., Budny, R. V., Ding, S., Hanson, J. M., Heidbrink, W. W., Lao, L. L., Li, G., ... Xu, G. (2015). Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D. Nuclear Fusion, 55(12), Article 123025. https://doi.org/10.1088/0029-5515/55/12/123025

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title = "Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D",

abstract = "Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by 30% relative to earlier work (Politzer et al 2005 Nucl. Fusion 45 417). The advancement was enabled by improved understanding of the 'relaxation oscillations', previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the 'relaxation oscillations' are coupled core-edge modes amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced to classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥80%, βN ≤ 4, βP ≥ 3, and βT ≥ 2%. These results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.",

keywords = "high beta, ion transport barrier, steady state, wall stabilization",

author = "Garofalo, {A. M.} and X. Gong and Grierson, {B. A.} and Q. Ren and Solomon, {W. M.} and Strait, {E. J.} and {Van Zeeland}, {M. A.} and Holcomb, {C. T.} and O. Meneghini and Smith, {S. P.} and Staebler, {G. M.} and B. Wan and R. Bravenec and Budny, {R. V.} and S. Ding and Hanson, {J. M.} and Heidbrink, {W. W.} and Lao, {L. L.} and G. Li and C. Pan and Petty, {C. C.} and J. Qian and C. Paz-Soldan and G. Xu",

note = "Publisher Copyright: {\textcopyright} 2015 General Atomics.",

year = "2015",

month = nov,

day = "16",

doi = "10.1088/0029-5515/55/12/123025",

language = "English",

volume = "55",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing",

number = "12",

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Garofalo, AM, Gong, X, Grierson, BA, Ren, Q, Solomon, WM, Strait, EJ, Van Zeeland, MA, Holcomb, CT, Meneghini, O, Smith, SP, Staebler, GM, Wan, B, Bravenec, R, Budny, RV, Ding, S, Hanson, JM, Heidbrink, WW, Lao, LL, Li, G, Pan, C, Petty, CC, Qian, J, Paz-Soldan, C & Xu, G 2015, 'Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D', Nuclear Fusion, vol. 55, no. 12, 123025. https://doi.org/10.1088/0029-5515/55/12/123025

TY - JOUR

T1 - Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

AU - Garofalo, A. M.

AU - Gong, X.

AU - Grierson, B. A.

AU - Ren, Q.

AU - Solomon, W. M.

AU - Strait, E. J.

AU - Van Zeeland, M. A.

AU - Holcomb, C. T.

AU - Meneghini, O.

AU - Smith, S. P.

AU - Staebler, G. M.

AU - Wan, B.

AU - Bravenec, R.

AU - Budny, R. V.

AU - Ding, S.

AU - Hanson, J. M.

AU - Heidbrink, W. W.

AU - Lao, L. L.

AU - Li, G.

AU - Pan, C.

AU - Petty, C. C.

AU - Qian, J.

AU - Paz-Soldan, C.

AU - Xu, G.

PY - 2015/11/16

Y1 - 2015/11/16

N2 - Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by 30% relative to earlier work (Politzer et al 2005 Nucl. Fusion 45 417). The advancement was enabled by improved understanding of the 'relaxation oscillations', previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the 'relaxation oscillations' are coupled core-edge modes amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced to classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥80%, βN ≤ 4, βP ≥ 3, and βT ≥ 2%. These results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.

AB - Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by 30% relative to earlier work (Politzer et al 2005 Nucl. Fusion 45 417). The advancement was enabled by improved understanding of the 'relaxation oscillations', previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the 'relaxation oscillations' are coupled core-edge modes amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced to classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥80%, βN ≤ 4, βP ≥ 3, and βT ≥ 2%. These results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.

KW - high beta

KW - ion transport barrier

KW - steady state

KW - wall stabilization

UR - http://www.scopus.com/inward/record.url?scp=84948175903&partnerID=8YFLogxK

U2 - 10.1088/0029-5515/55/12/123025

DO - 10.1088/0029-5515/55/12/123025

M3 - Article

AN - SCOPUS:84948175903

SN - 0029-5515

VL - 55

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 12

M1 - 123025

ER -

Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

Abstract

Funding

Keywords

UN SDGs

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