Tokamak Operation with Safety Factor q95<2 via Control of MHD Stability

Piovesan, Paolo; Hanson, Jeremy M.; Martin, Piero; Navratil, Gerald A.; Turco, Francesca; Bialek, James; La Haye, Robert J.; Lanctot, Matthew J.; Okabayashi, Michio; Paz-Soldan, Carlos; Strait, Edward J.; Turnbull, Alan D.; Zanca, P.; Baruzzo, M.; Bolzonella, T.; Hyatt, Alan W.; Jackson, G. L.; Marrelli, L.; Piron, L.; Shiraki, Daisuke

doi:10.1103/PhysRevLett.113.045003

Title: Tokamak Operation with Safety Factor $q_{95} < 2$ via Control of MHD Stability

Journal Article · Thu Jul 24 00:00:00 EDT 2014 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.113.045003· OSTI ID:1367085

Piovesan, Paolo ^[1]; Hanson, Jeremy M. ^[2]; Martin, Piero ^[1]; Navratil, Gerald A. ^[2]; Turco, Francesca ^[2]; Bialek, James ^[2]; La Haye, Robert J. ^[3]; Lanctot, Matthew J. ^[3]; Okabayashi, Michio ^[4]; Paz-Soldan, Carlos ^[5]; Strait, Edward J. ^[3]; Turnbull, Alan D. ^[3]; Zanca, P. ^[1]; Baruzzo, M. ^[1]; Bolzonella, T. ^[1]; Hyatt, Alan W. ^[3]; Jackson, G. L. ^[3]; Marrelli, L. ^[1]; Piron, L. ^[1]; Shiraki, Daisuke ^[2]

Consorzio RFX, Padova (Italy)
Columbia Univ., New York, NY (United States)
General Atomics, San Diego, CA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

Magnetic feedback control of the resistive-wall mode has enabled DIII-D to access stable operation at safety factor q95 = 1:9 in divertor plasmas for 150 instability growth times. Magnetohydrodynamic stability sets a hard, disruptive limit on the minimum edge safety factor achievable in a tokamak, or on the maximum plasma current at given toroidal magnetic eld. In tokamaks with a divertor, the limit occurs at q95 = 2, as con rmed in DIII-D. Since the energy con cement time scales linearly with current, this also bounds the performance of a fusion reactor. DIII-D has overcome this limit, opening a whole new high-current regime not accessible before. This result brings signi cant possible bene ts in terms of fusion performance, but it also extends resistive wall mode physics and its control to conditions never explored before. In present experiments, q95 < 2 operation is eventually halted by voltage limits reached in the feedback power supplies, not by intrinsic physics issues. Improvements to power supplies and to control algorithms have the potential to further extend this regime.

View Accepted Manuscript (DOE)

Cite

Export

Save

Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: FC02-04ER54698

OSTI ID:: 1367085

Journal Information:: Physical Review Letters, Vol. 113, Issue 4; ISSN 0031-9007

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 16 works

Citation information provided by
Web of Science

References (24)

A Kalman filter for feedback control of rotating external kink instabilities in the presence of noise Hanson, Jeremy M.; De Bono, Bryan; Levesque, Jeffrey P. Physics of Plasmas, Vol. 16, Issue 5 https://doi.org/10.1063/1.3110110	journal	May 2009
Feedback control model of the m = 2, n = 1 resistive wall mode in a circular plasma Zanca, P.; Marrelli, L.; Paccagnella, R. Plasma Physics and Controlled Fusion, Vol. 54, Issue 9 https://doi.org/10.1088/0741-3335/54/9/094004	journal	August 2012
Separation of β̄ _p and ℓ _i in tokamaks of non-circular cross-section Lao, L. L.; John, H. St.; Stambaugh, R. D. Nuclear Fusion, Vol. 25, Issue 10 https://doi.org/10.1088/0029-5515/25/10/004	journal	October 1985
Disruptions in JET Wesson, J. A.; Gill, R. D.; Hugon, M. Nuclear Fusion, Vol. 29, Issue 4 https://doi.org/10.1088/0029-5515/29/4/009	journal	April 1989
Stabilization of the external kink and the resistive wall mode Chu, M. S.; Okabayashi, M. Plasma Physics and Controlled Fusion, Vol. 52, Issue 12 https://doi.org/10.1088/0741-3335/52/12/123001	journal	October 2010
Examination of energy confinement in DIII-D at small values of the plasma safety factor Schissel, D. P.; Kellman, A. G.; Snider, R. T. Nuclear Fusion, Vol. 32, Issue 1 https://doi.org/10.1088/0029-5515/32/1/I09	journal	January 1992
H-mode confinement at low q and high beta in JET Lazzaro, E.; Tanga, A.; Huysmans, G. Nuclear Fusion, Vol. 30, Issue 10 https://doi.org/10.1088/0029-5515/30/10/013	journal	October 1990
The limits and challenges of error field correction for ITER Buttery, R. J.; Boozer, A. H.; Liu, Y. Q. Physics of Plasmas, Vol. 19, Issue 5 https://doi.org/10.1063/1.3694655	journal	May 2012
Enhanced ITER resistive wall mode feedback performance using optimal control techniques Katsuro-Hopkins, O.; Bialek, J.; Maurer, D. A. Nuclear Fusion, Vol. 47, Issue 9 https://doi.org/10.1088/0029-5515/47/9/012	journal	August 2007
Application of dimensionless parameter scaling techniques to the design and interpretation of magnetic fusion experiments Luce, T. C.; Petty, C. C.; Cordey, J. G. Plasma Physics and Controlled Fusion, Vol. 50, Issue 4 https://doi.org/10.1088/0741-3335/50/4/043001	journal	March 2008
Effects of the safety factor and the internal inductance on MHD activities and energy confinement in JT-60U Kamada, Y.; Takizuka, T.; Kikuchi, M. Nuclear Fusion, Vol. 33, Issue 2 https://doi.org/10.1088/0029-5515/33/2/I04	journal	February 1993
GATO: An MHD stability code for axisymmetric plasmas with internal separatrices Bernard, L. C.; Helton, F. J.; Moore, R. W. Computer Physics Communications, Vol. 24, Issue 3-4 https://doi.org/10.1016/0010-4655(81)90160-0	journal	December 1981
Modeling of active control of external magnetohydrodynamic instabilities Bialek, James; Boozer, Allen H.; Mauel, M. E. Physics of Plasmas, Vol. 8, Issue 5 https://doi.org/10.1063/1.1362532	journal	May 2001
Chapter 3: MHD stability, operational limits and disruptions Mhd, ITER Physics Expert Group on Disrup; Editors, ITER Physics Basis Nuclear Fusion, Vol. 39, Issue 12 https://doi.org/10.1088/0029-5515/39/12/303	journal	December 1999
Chapter 2: Plasma confinement and transport Transport, ITER Physics Expert Group on Confin; Database, ITER Physics Expert Group on Confin; Editors, ITER Physics Basis Nuclear Fusion, Vol. 39, Issue 12 https://doi.org/10.1088/0029-5515/39/12/302	journal	December 1999
Calculations of two-fluid magnetohydrodynamic axisymmetric steady-states Ferraro, N. M.; Jardin, S. C. Journal of Computational Physics, Vol. 228, Issue 20 https://doi.org/10.1016/j.jcp.2009.07.015	journal	November 2009
Experiments and modelling of external kink mode control using modular internal feedback coils Sunn Pedersen, T.; Maurer, D. A.; Bialek, J. Nuclear Fusion, Vol. 47, Issue 9 https://doi.org/10.1088/0029-5515/47/9/028	journal	August 2007
RWM control studies on RFX-mod with a limited set of active coils Baruzzo, M.; Bolzonella, T.; Liu, Y. Q. Nuclear Fusion, Vol. 52, Issue 10 https://doi.org/10.1088/0029-5515/52/10/103001	journal	August 2012
Error Field Amplification and Rotation Damping in Tokamak Plasmas Boozer, Allen H. Physical Review Letters, Vol. 86, Issue 22 https://doi.org/10.1103/PhysRevLett.86.5059	journal	May 2001
High performance stationary discharges in the DIII-D tokamak Luce, T. C.; Wade, M. R.; Ferron, J. R. Physics of Plasmas, Vol. 11, Issue 5 https://doi.org/10.1063/1.1704644	journal	May 2004
Resistive wall mode stabilization by slow plasma rotation in DIII-D tokamak discharges with balanced neutral beam injection Strait, E. J.; Garofalo, A. M.; Jackson, G. L. Physics of Plasmas, Vol. 14, Issue 5 https://doi.org/10.1063/1.2472599	journal	May 2007
Feedback stabilization of nonaxisymmetric resistive wall modes in tokamaks. I. Electromagnetic model Liu, Y. Q.; Bondeson, A.; Fransson, C. M. Physics of Plasmas, Vol. 7, Issue 9 https://doi.org/10.1063/1.1287744	journal	September 2000
Sustained Stabilization of the Resistive-Wall Mode by Plasma Rotation in the DIII-D Tokamak Garofalo, A. M.; Strait, E. J.; Johnson, L. C. Physical Review Letters, Vol. 89, Issue 23 https://doi.org/10.1103/PhysRevLett.89.235001	journal	November 2002
Improved dynamic response of magnetic feedback in RFX-mod and DIII-D Piron, L.; Hanson, J. M.; In, Y. Plasma Physics and Controlled Fusion, Vol. 53, Issue 8 https://doi.org/10.1088/0741-3335/53/8/084004	journal	May 2011

Cited By (1)

Kink instabilities of the post-disruption runaway electron beam at low safety factor Paz-Soldan, C.; Eidietis, N. W.; Liu, Y. Q. Plasma Physics and Controlled Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1361-6587/aafd15	journal	March 2019

Similar Records

Europium mixed-valence, long-range magnetic order, and dynamic magnetic response in

{EuCu}_{2} {(Si}_{x} {Ge}_{1 - x})_{2}

Journal Article · Tue Nov 01 00:00:00 EDT 2016 · Physical Review B · OSTI ID:1367085

Nemkovski, Krill S.; Kozlenko, D. P.; Alekseev, Pavel A.; +9 more

Branching fraction measurement of

J / ψ \to K_{S} K_{L}

and search for

J / ψ \to K_{S} K_{S}

Journal Article · Mon Dec 04 00:00:00 EST 2017 · Physical Review D · OSTI ID:1367085

Ablikim, M.; Achasov, M. N.; Ahmed, S.; +444 more

E \times B

Flux Driven Detachment Bifurcation in the DIII-D Tokamak

Journal Article · Wed Aug 01 00:00:00 EDT 2018 · Physical Review Letters · OSTI ID:1367085

Jaervinen, A. E.; Allen, S. L.; Eldon, D.; +9 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Title: Tokamak Operation with Safety Factor q 95 < 2 via Control of MHD Stability

Citation Formats

References (24)

Cited By (1)

Similar Records

Related Subjects

Title: Tokamak Operation with Safety Factor $q_{95} < 2$ via Control of MHD Stability