Impact of neoclassical tearing mode–turbulence multi-scale interaction in global confinement degradation and magnetic island stability

Bardoczi, Lazlo; Carter, Troy A.; La Haye, Robert J.; Rhodes, Terry L.; McKee, George R.

doi:10.1063/1.5004987

Title: Impact of neoclassical tearing mode–turbulence multi-scale interaction in global confinement degradation and magnetic island stability

Journal Article · Fri Dec 08 00:00:00 EST 2017 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.5004987· OSTI ID:1412539

Bardoczi, Lazlo ^[1];

^[2]; La Haye, Robert J. ^[3]; Rhodes, Terry L. ^[2]; McKee, George R. ^[4]

Univ. of California, Los Angeles, CA (United States); Oak Ridge Associated Univ., Oak Ridge, TN (United States)
Univ. of California, Los Angeles, CA (United States)
General Atomics, San Diego, CA (United States)
Univ. of Wisconsin-Madison, Madison, WI (United States)

Recent measurements of turbulent density ($$\tilde{n}$$) and electron-temperature ($$\tilde{T}$$_e) fluctuations have reported turbulence modifications by Neoclassical Tearing Mode (NTM) islands: turbulence decreases (increases) inside (outside) the island region when the island width (W) exceeds a threshold (W_T), in qualitative agreement with gyrokinetic simulations. As the cross-field transport in tokamaks is dominantly driven by turbulence, these observations call into question the conventional understanding of confinement degradation by NTMs and magnetic island stability physics. The experimental data presented here support the following points: (i) When profiles flatten at the O-point and gradients increase outside of the island, $$\tilde{n}$$ decreases (increases) inside (outside) the island. Along with the parallel transport resulting in increased fluxes inside the island, the increase of $$\tilde{n}$$ outside of the island offers an explanation for the temporal increase of fluxes in that region. As the plasma stored energy (WMHD) gradually decreases in synchronization with the island growth and saturation, gradients, $$\tilde{n}$$ and fluxes also decrease outside the island until they become about the same as before NTM onset. These fluxes balance the constant sources, and the plasma comes to a steady state at lower W_MHD. (ii) Turbulence reduction in the O-point region has a destabilizing effect on the island. This effect is, however, nearly compensated by the reduced confinement. In conclusion, these observations suggest that driving turbulence in the island region could lead to smaller saturated islands offering a path toward better confinement and safer operation of reactor-scale fusion devices.

View Accepted Manuscript (DOE)

View Accepted Manuscript (Publisher)

Cite

Export

Save

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

Sponsoring Organization:: USDOE Office of Nuclear Energy (NE)

Grant/Contract Number:: FC02-04ER54698; FG02-08ER54984; FG03-86ER53266

OSTI ID:: 1412539

Alternate ID(s):: OSTI ID: 1411994

Journal Information:: Physics of Plasmas, Vol. 24, Issue 12; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 19 works

Citation information provided by
Web of Science

References (37)

The beam emission spectroscopy diagnostic on the DIII-D tokamak McKee, G.; Ashley, R.; Durst, R. Review of Scientific Instruments, Vol. 70, Issue 1 https://doi.org/10.1063/1.1149416	journal	January 1999
Electron cyclotron emission radiometer upgrade on the DIII-D tokamak Austin, M. E.; Lohr, J. Review of Scientific Instruments, Vol. 74, Issue 3 https://doi.org/10.1063/1.1530387	journal	March 2003
The influence of the ion polarization current on magnetic island stability in a tokamak plasma Fitzpatrick, R.; Waelbroeck, F. L.; Militello, F. Physics of Plasmas, Vol. 13, Issue 12 https://doi.org/10.1063/1.2402914	journal	December 2006
The bootstrap current and its consequences Peeters, A. G. Plasma Physics and Controlled Fusion, Vol. 42, Issue 12B https://doi.org/10.1088/0741-3335/42/12B/318	journal	December 2000
Helical temperature perturbations associated with tearing modes in tokamak plasmas Fitzpatrick, Richard Physics of Plasmas, Vol. 2, Issue 3 https://doi.org/10.1063/1.871434	journal	March 1995
Plasma flows and fluctuations with magnetic islands in the edge plasmas of J-TEXT tokamak Zhao, K. J.; Shi, Y. J.; Hahn, S. H. Nuclear Fusion, Vol. 55, Issue 7 https://doi.org/10.1088/0029-5515/55/7/073022	journal	June 2015
Threshold for metastable tearing modes in DIII-D Haye, R. J. La; Sauter, O. Nuclear Fusion, Vol. 38, Issue 7 https://doi.org/10.1088/0029-5515/38/7/303	journal	July 1998
Multi-field/-scale interactions of turbulence with neoclassical tearing mode magnetic islands in the DIII-D tokamak Bardóczi, L.; Rhodes, T. L.; Bañón Navarro, A. Physics of Plasmas, Vol. 24, Issue 5 https://doi.org/10.1063/1.4977533	journal	May 2017
The nonlinear coupling between gyroradius scale turbulence and mesoscale magnetic islands in fusion plasmas Hornsby, W. A.; Peeters, A. G.; Snodin, A. P. Physics of Plasmas, Vol. 17, Issue 9 https://doi.org/10.1063/1.3467502	journal	September 2010
Beta limits in long-pulse tokamak discharges Sauter, O.; La Haye, R. J.; Chang, Z. Physics of Plasmas, Vol. 4, Issue 5 https://doi.org/10.1063/1.872270	journal	May 1997
Improved accuracy in the estimation of the tearing mode stability parameters (Δ′ and w _c ) using 2D ECEI data in KSTAR Choi, Minjun J.; Yun, Gunsu S.; Lee, Woochang Nuclear Fusion, Vol. 54, Issue 8 https://doi.org/10.1088/0029-5515/54/8/083010	journal	June 2014
Improved charge-coupled device detectors for high-speed, charge exchange spectroscopy studies on the DIII-D tokamak Burrell, K. H.; Gohil, P.; Groebner, R. J. Review of Scientific Instruments, Vol. 75, Issue 10 https://doi.org/10.1063/1.1787949	journal	October 2004
Nonlinear growth of the tearing mode Rutherford, P. H. Physics of Fluids, Vol. 16, Issue 11 https://doi.org/10.1063/1.1694232	journal	January 1973
Shrinking of core neoclassical tearing mode magnetic islands due to edge localized modes and the role of ion-scale turbulence in island recovery in DIII-D Bardóczi, L.; Rhodes, T. L.; Carter, T. A. Physics of Plasmas, Vol. 24, Issue 6 https://doi.org/10.1063/1.4985078	journal	June 2017
Modulation of Core Turbulent Density Fluctuations by Large-Scale Neoclassical Tearing Mode Islands in the DIII-D Tokamak Bardóczi, L.; Rhodes, T. L.; Carter, T. A. Physical Review Letters, Vol. 116, Issue 21 https://doi.org/10.1103/PhysRevLett.116.215001	journal	May 2016
Testing instabilities and microturbulence in TEXT Yu, C.; Brower, D. L.; Zhao, S. Nuclear Fusion, Vol. 32, Issue 9 https://doi.org/10.1088/0029-5515/32/9/I04	journal	September 1992
Heat pulse propagation studies around magnetic islands induced by the Dynamic Ergodic Divertor in TEXTOR Spakman, G. W.; Hogeweij, G. M. D.; Jaspers, R. J. E. Nuclear Fusion, Vol. 48, Issue 11 https://doi.org/10.1088/0029-5515/48/11/115005	journal	September 2008
Experimental identification of nonlinear coupling between (intermediate, small)-scale microturbulence and an MHD mode in the core of a superconducting tokamak Sun, P. J.; Li, Y. D.; Ren, Y. Nuclear Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/1741-4326/aa8a91	journal	November 2017
Fiber optic two-color vibration compensated interferometer for plasma density measurements Van Zeeland, M. A.; Boivin, R. L.; Carlstrom, T. N. Review of Scientific Instruments, Vol. 77, Issue 10 https://doi.org/10.1063/1.2336437	journal	October 2006
The effect of sheared toroidal rotation on pressure driven magnetic islands in toroidal plasmas Hegna, C. C. Physics of Plasmas, Vol. 23, Issue 5 https://doi.org/10.1063/1.4952627	journal	May 2016
The role of asymmetries in the growth and suppression of neoclassical tearing modes De Lazzari, D.; Westerhof, E. Plasma Physics and Controlled Fusion, Vol. 53, Issue 3 https://doi.org/10.1088/0741-3335/53/3/035020	journal	February 2011
On seed island generation and the non-linear self-consistent interaction of the tearing mode With electromagnetic gyro-kinetic turbulence Hornsby, W. A.; Migliano, P.; Buchholz, R. Plasma Physics and Controlled Fusion, Vol. 57, Issue 5 https://doi.org/10.1088/0741-3335/57/5/054018	journal	April 2015
Observation of Reduced Heat Transport inside the Magnetic Island O Point in the Large Helical Device Inagaki, S.; Tamura, N.; Ida, K. Physical Review Letters, Vol. 92, Issue 5 https://doi.org/10.1103/PhysRevLett.92.055002	journal	February 2004
Multiscale interaction between a large scale magnetic island and small scale turbulence Choi, M. J.; Kim, J.; Kwon, J. -M. Nuclear Fusion, Vol. 57, Issue 12 https://doi.org/10.1088/1741-4326/aa86fe	journal	October 2017
A signature for turbulence driven magnetic islands Agullo, O.; Muraglia, M.; Poyé, A. Physics of Plasmas, Vol. 21, Issue 9 https://doi.org/10.1063/1.4894699	journal	September 2014
Non-perturbative measurement of cross-field thermal diffusivity reduction at the O-point of 2/1 neoclassical tearing mode islands in the DIII-D tokamak Bardóczi, L.; Rhodes, T. L.; Carter, T. A. Physics of Plasmas, Vol. 23, Issue 5 https://doi.org/10.1063/1.4948560	journal	May 2016
Experimental observation of multi-scale interactions among kink /tearing modes and high-frequency fluctuations in the HL-2A core NBI plasmas Chen, W.; Jiang, M.; Xu, Y. Nuclear Fusion, Vol. 57, Issue 11 https://doi.org/10.1088/1741-4326/aa7eee	journal	August 2017
Global energy confinement degradation due to macroscopic phenomena in tokamaks Chang, Z.; Callen, J. D. Nuclear Fusion, Vol. 30, Issue 2 https://doi.org/10.1088/0029-5515/30/2/003	journal	February 1990
The influence of finite radial transport on the structure and evolution of m / n = 2/1 neoclassical tearing modes on MAST Snape, J. A.; Gibson, K. J.; O'Gorman, T. Plasma Physics and Controlled Fusion, Vol. 54, Issue 8 https://doi.org/10.1088/0741-3335/54/8/085001	journal	May 2012
Effect of magnetic islands on profiles, flows, turbulence and transport in nonlinear gyrokinetic simulations Navarro, A. Bañón; Bardóczi, L.; Carter, T. A. Plasma Physics and Controlled Fusion, Vol. 59, Issue 3 https://doi.org/10.1088/1361-6587/aa557e	journal	February 2017
Influence of neoclassical tearing modes on energy confinement Günter, S.; Gude, A.; Maraschek, M. Plasma Physics and Controlled Fusion, Vol. 41, Issue 6 https://doi.org/10.1088/0741-3335/41/6/306	journal	January 1999
Temporal-spatial structures of plasmas flows and turbulence around tearing mode islands in the edge tokamak plasmas Zhao, K. J.; Nagashima, Y.; Li, F. M. Nuclear Fusion, Vol. 57, Issue 12 https://doi.org/10.1088/1741-4326/aa8341	journal	September 2017
Reduction of Ion Thermal Diffusivity Inside a Magnetic Island in JT-60U Tokamak Plasma Ida, K.; Kamiya, K.; Isayama, A. Physical Review Letters, Vol. 109, Issue 6 https://doi.org/10.1103/PhysRevLett.109.065001	journal	August 2012
Effect of nonlinear energy transport on neoclassical tearing mode stability in tokamak plasmas Fitzpatrick, Richard Physics of Plasmas, Vol. 24, Issue 5 https://doi.org/10.1063/1.4982610	journal	April 2017
Island bootstrap current modification of the nonlinear dynamics of the tearing mode Carrera, R.; Hazeltine, R. D.; Kotschenreuther, M. Physics of Fluids, Vol. 29, Issue 4 https://doi.org/10.1063/1.865682	journal	January 1986
Effect of Nonlinear Energy Transport on Neoclassical Tearing Mode Stability in Tokamak Plasmas Fitzpatrick, Richard arXiv https://doi.org/10.48550/arxiv.1612.05798	text	January 2016
Multiscale interaction between a large scale magnetic island and small scale turbulence Choi, M. J.; Kim, J.; Kwon, J. -M. arXiv https://doi.org/10.48550/arxiv.1705.09487	text	January 2017

Cited By (8)

A possible mechanism for confinement power degradation in the TJ-II stellarator van Milligen, B. Ph.; Carreras, B. A.; Hidalgo, C. Physics of Plasmas, Vol. 25, Issue 6 https://doi.org/10.1063/1.5029881	journal	June 2018
Multi-scale interactions between turbulence and magnetic islands and parity mixture—a review Ishizawa, A.; Kishimoto, Y.; Nakamura, Y. Plasma Physics and Controlled Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1361-6587/ab06a8	journal	March 2019
Quantitative modeling of neoclassical tearing mode driven fast ion transport in integrated TRANSP simulations Bardóczi, L.; Podestà, M.; Heidbrink, W. W. Plasma Physics and Controlled Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1361-6587/ab0f08	journal	April 2019
Interaction of magnetic islands with turbulent electron temperature fluctuations in DIII-D and in GENE nonlinear gyrokinetic simulations Bardóczi, L.; Sung, C.; Navarro, A. Bañón Plasma Physics and Controlled Fusion, Vol. 62, Issue 2 https://doi.org/10.1088/1361-6587/ab5c69	journal	December 2019
Non-linear simulations of neoclassical tearing mode control by externally driven RF current and heating, with application to ITER Widmer, Fabien; Maget, Patrick; Février, Olivier Nuclear Fusion, Vol. 59, Issue 10 https://doi.org/10.1088/1741-4326/ab300f	journal	August 2019
Reduced energetic particle transport models enable comprehensive time-dependent tokamak simulations Podestà, M.; Bardóczi, L.; Collins, C. S. Nuclear Fusion, Vol. 59, Issue 10 https://doi.org/10.1088/1741-4326/ab3112	journal	August 2019
L – H transition trigger physics in ITER-similar plasmas with applied n = 3 magnetic perturbations Schmitz, L.; Kriete, D. M.; Wilcox, R. S. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab36bf	journal	September 2019
Controlled neoclassical tearing mode (NTM) healing by fueling pellets and its impact on electron cyclotron current drive requirements for complete NTM stabilization Bardóczi, L.; Choi, M. J.; Bañón Navarro, A. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab472d	journal	October 2019

Similar Records

Shrinking of core neoclassical tearing mode magnetic islands due to edge localized modes and the role of ion-scale turbulence in island recovery in DIII-D

Journal Article · Thu Jun 08 00:00:00 EDT 2017 · Physics of Plasmas · OSTI ID:1412539

Bardóczi, Laszlo; Rhodes, Terry L.; Carter, Troy A.; +3 more

Modulation of core turbulent density fluctuations by large-scale neoclassical tearing mode islands in the DIII-D tokamak

Journal Article · Thu May 26 00:00:00 EDT 2016 · Physical Review Letters · OSTI ID:1412539

Bardoczi, L.; Rhodes, T. L.; Carter, T. A.; +4 more

Multi-field/-scale interactions of turbulence with neoclassical tearing mode magnetic islands in the DIII-D tokamak

Journal Article · Fri Mar 03 00:00:00 EST 2017 · Physics of Plasmas · OSTI ID:1412539

Bardoczi, Laszlo; Rhodes, Terry L.; Navarro, Alejandro Banon; +7 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Title: Impact of neoclassical tearing mode–turbulence multi-scale interaction in global confinement degradation and magnetic island stability

Citation Formats

References (37)

Cited By (8)

Similar Records

Related Subjects