Micro-tearing mode dominated electron heat transport in DIII-D H-mode pedestal

Chen, J.; Jian, X.; Brower, D. L.; Haskey, S. R.; Yan, Z.; Groebner, R.; Wang, H. Q.; Rhodes, T. L.; Laggner, F.; Ding, W.; Barada, K.; Banerjee, S.

doi:10.1088/1741-4326/accafb

Title: Micro-tearing mode dominated electron heat transport in DIII-D H-mode pedestal

Journal Article · 19 April 2023 · Nuclear Fusion

DOI: https://doi.org/10.1088/1741-4326/accafb · OSTI ID:1970796

; Jian, X.; Brower, D. L.;

; Yan, Z.;

;

; Ding, W.; Barada, K.;

Abstract A new, comprehensive set of evidence reveals that Micro-Tearing Modes (MTMs) dominate pedestal electron heat transport in an H-mode experiment in the DIII-D tokamak. The experiment investigates the role of MTMs by scanning pedestal collisionality, a main drive of MTM instability, from 0.43 to 0.84 on the pedestal top. Broadband (150–800 kHz) magnetic and density fluctuations originating from the pedestal gradient region and highly consistent with MTMs are observed, with amplitude increasing during the scan. The higher magnetic fluctuation amplitude correlates with a lower pedestal electron temperature gradient, implying MTMs may regulate the pedestal electron heat transport. The collisionality scan results in profile and transport changes consistent with predicted transport capability of MTMs: (1) experimentally-determined electron heat diffusivity increases ∼40% at the location where the broadband density fluctuations peak; (2) ion heat diffusivity has less increase (<20%); and (3) a locally flattened region in the electron temperature pedestal is observed at high collisionality. A local, linear gyrokinetic simulation finds MTMs as the most unstable mode in the pedestal gradient region. In addition, local, nonlinear simulations suggest MTMs can dominate and drive experimentally-relevant, megawatt-level electron heat flux. This result establishes MTMs as an effective transport mechanism in the H-mode pedestal, in particular at high collisionality.

View Journal Article

Cite

Export

Save

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1970796

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 6 Vol. 63; ISSN 0029-5515

Publisher:: IOP PublishingCopyright Statement

Country of Publication:: IAEA

Language:: English

References (37)

A high-accuracy Eulerian gyrokinetic solver for collisional plasmas Candy, J.; Belli, E. A.; Bravenec, R. V. Journal of Computational Physics, Vol. 324 https://doi.org/10.1016/j.jcp.2016.07.039	journal	November 2016
Compatibility of detached divertor operation with robust edge pedestal performance Leonard, A. W.; Makowski, M. A.; McLean, A. G. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.11.007	journal	August 2015
Design and operation of the multipulse Thomson scattering diagnostic on DIII‐D (invited) Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C. Review of Scientific Instruments, Vol. 63, Issue 10 https://doi.org/10.1063/1.1143545	journal	October 1992
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes Snyder, P. B.; Wilson, H. R.; Ferron, J. R. Physics of Plasmas, Vol. 9, Issue 5 https://doi.org/10.1063/1.1449463	journal	May 2002
Turbulence imaging and applications using beam emission spectroscopy on DIII-D (invited) McKee, G. R.; Fenzi, C.; Fonck, R. J. Review of Scientific Instruments, Vol. 74, Issue 3 https://doi.org/10.1063/1.1535248	journal	March 2003
Pedestal density fluctuation dynamics during the inter-ELM cycle in DIII-D Yan, Z.; McKee, G. R.; Groebner, R. J. Physics of Plasmas, Vol. 18, Issue 5 https://doi.org/10.1063/1.3590936	journal	May 2011
Correlations between quasi-coherent fluctuations and the pedestal evolution during the inter-edge localized modes phase on DIII-Da) Diallo, A.; Groebner, R. J.; Rhodes, T. L. Physics of Plasmas, Vol. 22, Issue 5 https://doi.org/10.1063/1.4921148	journal	May 2015
Faraday-effect polarimeter diagnostic for internal magnetic field fluctuation measurements in DIII-D Chen, J.; Ding, W. X.; Brower, D. L. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4960056	journal	August 2016
A Faraday-effect polarimeter for fast magnetic dynamics measurement on DIII-D Chen, J.; Ding, W. X.; Brower, D. L. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5035276	journal	October 2018
Active spectroscopy measurements of the deuterium temperature, rotation, and density from the core to scrape off layer on the DIII-D tokamak (invited) Haskey, S. R.; Grierson, B. A.; Stagner, L. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5038349	journal	October 2018
Internal measurement of magnetic turbulence in ELMy H-mode tokamak plasmas Chen, J.; Brower, D. L.; Ding, W. X. Physics of Plasmas, Vol. 27, Issue 12 https://doi.org/10.1063/5.0029996	journal	December 2020
Pedestal magnetic turbulence measurements in ELMy H-mode DIII-D plasmas by Faraday-effect polarimetry Chen, J.; Brower, D. L.; Ding, W. X. Physics of Plasmas, Vol. 28, Issue 2 https://doi.org/10.1063/5.0039154	journal	February 2021
Ion thermal transport in the H-mode edge transport barrier on DIII-D Haskey, S. R.; Ashourvan, Arash; Banerjee, S. Physics of Plasmas, Vol. 29, Issue 1 https://doi.org/10.1063/5.0072155	journal	January 2022
A survey of pedestal magnetic fluctuations using gyrokinetics and a global reduced model for microtearing stability Curie, M. T.; Larakers, J. L.; Hatch, D. R. Physics of Plasmas, Vol. 29, Issue 4 https://doi.org/10.1063/5.0084842	journal	April 2022
Gyrokinetic analysis of inter-edge localized mode transport mechanisms in a DIII-D pedestal Halfmoon, M. R.; Hatch, D. R.; Kotschenreuther, M. T. Physics of Plasmas, Vol. 29, Issue 11 https://doi.org/10.1063/5.0102152	journal	November 2022
Confinement degradation of ELMy H modes at high density and/or radiated power fraction Matthews), JET Team (prepared by G. F. Nuclear Fusion, Vol. 39, Issue 11Y https://doi.org/10.1088/0029-5515/39/11Y/308	journal	November 1999
A first-principles predictive model of the pedestal height and width: development, testing and ITER optimization with the EPED model Snyder, P. B.; Groebner, R. J.; Hughes, J. W. Nuclear Fusion, Vol. 51, Issue 10 https://doi.org/10.1088/0029-5515/51/10/103016	journal	August 2011
Critical edge parameters for H-mode transition in DIII-D Groebner, R. J.; Carlstrom, T. N. Plasma Physics and Controlled Fusion, Vol. 40, Issue 5 https://doi.org/10.1088/0741-3335/40/5/021	journal	May 1998
High frequency magnetic fluctuations correlated with the inter-ELM pedestal evolution in ASDEX Upgrade Laggner, F. M.; Wolfrum, E.; Cavedon, M. Plasma Physics and Controlled Fusion, Vol. 58, Issue 6 https://doi.org/10.1088/0741-3335/58/6/065005	journal	May 2016
Compatibility of separatrix density scaling for divertor detachment with H-mode pedestal operation in DIII-D Leonard, A. W.; McLean, A. G.; Makowski, M. A. Nuclear Fusion, Vol. 57, Issue 8 https://doi.org/10.1088/1741-4326/aa778c	journal	July 2017
DIII-D research towards establishing the scientific basis for future fusion reactors Petty, C. C. Nuclear Fusion, Vol. 59, Issue 11 https://doi.org/10.1088/1741-4326/ab024a	journal	June 2019
Gyrokinetic analysis and simulation of pedestals to identify the culprits for energy losses using ‘fingerprints’ Kotschenreuther, M.; Liu, X.; Hatch, D. R. Nuclear Fusion, Vol. 59, Issue 9 https://doi.org/10.1088/1741-4326/ab1fa2	journal	July 2019
Pedestal structure, stability and scalings in JET-ILW: the EUROfusion JET-ILW pedestal database Frassinetti, L.; Saarelma, S.; Verdoolaege, G. Nuclear Fusion, Vol. 61, Issue 1 https://doi.org/10.1088/1741-4326/abb79e	journal	November 2020
Microtearing modes as the source of magnetic fluctuations in the JET pedestal Hatch, D. R.; Kotschenreuther, M.; Mahajan, S. M. Nuclear Fusion, Vol. 61, Issue 3 https://doi.org/10.1088/1741-4326/abd21a	journal	February 2021
Testing predictions of electron scale turbulent pedestal transport in two DIII-D ELMy H-modes Guttenfelder, W.; Groebner, R. J.; Canik, J. M. Nuclear Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1741-4326/abecc7	journal	April 2021
Time-dependent experimental identification of inter-ELM microtearing modes in the tokamak edge on DIII-D Nelson, A. O.; Laggner, F. M.; Diallo, A. Nuclear Fusion, Vol. 61, Issue 11 https://doi.org/10.1088/1741-4326/ac27ca	journal	October 2021
Identifying the microtearing modes in the pedestal of DIII-D H-modes using gyrokinetic simulations Hassan, Ehab; Hatch, D. R.; Halfmoon, M. R. Nuclear Fusion, Vol. 62, Issue 2 https://doi.org/10.1088/1741-4326/ac3be5	journal	December 2021
Experimental study on the role of the target electron temperature as a key parameter linking recycling to plasma performance in JET-ILW* Lomanowski, B.; Dunne, M.; Vianello, N. Nuclear Fusion, Vol. 62, Issue 6 https://doi.org/10.1088/1741-4326/ac5668	journal	April 2022
Gyrokinetic simulations compared with magnetic fluctuations diagnosed with a Faraday-effect radial interferometer-polarimeter in the DIII-D pedestal Curie, M. T.; Hatch, D. R.; Halfmoon, M. Nuclear Fusion, Vol. 62, Issue 12 https://doi.org/10.1088/1741-4326/ac9b76	journal	November 2022
Electromagnetic Transport from Microtearing Mode Turbulence Guttenfelder, W.; Candy, J.; Kaye, S. M. Physical Review Letters, Vol. 106, Issue 15 https://doi.org/10.1103/PhysRevLett.106.155004	journal	April 2011
Kinetic Instabilities that Limit β in the Edge of a Tokamak Plasma: A Picture of an H -Mode Pedestal Dickinson, D.; Roach, C. M.; Saarelma, S. Physical Review Letters, Vol. 108, Issue 13 https://doi.org/10.1103/PhysRevLett.108.135002	journal	March 2012
Global Gyrokinetic Simulation of Tokamak Edge Pedestal Instabilities Wan, Weigang; Parker, Scott E.; Chen, Yang Physical Review Letters, Vol. 109, Issue 18 https://doi.org/10.1103/PhysRevLett.109.185004	journal	November 2012
Role of Microtearing Turbulence in DIII-D High Bootstrap Current Fraction Plasmas Jian, X.; Holland, C.; Candy, J. Physical Review Letters, Vol. 123, Issue 22 https://doi.org/10.1103/PhysRevLett.123.225002	journal	November 2019
Global Theory of Microtearing Modes in the Tokamak Pedestal Larakers, J. L.; Curie, M.; Hatch, D. R. Physical Review Letters, Vol. 126, Issue 22 https://doi.org/10.1103/PhysRevLett.126.225001	journal	June 2021
Electron Heat Transport in a Tokamak with Destroyed Magnetic Surfaces Rechester, A. B.; Rosenbluth, M. N. Physical Review Letters, Vol. 40, Issue 1 https://doi.org/10.1103/PhysRevLett.40.38	journal	January 1978
Development of an Edge Transport Barrier at the H-Mode Transition of ASDEX Wagner, F.; Fussmann, G.; Grave, T. Physical Review Letters, Vol. 53, Issue 15 https://doi.org/10.1103/PhysRevLett.53.1453	journal	October 1984
Coherence Significance Levels Thompson, Rory O. R. Y. Journal of the Atmospheric Sciences, Vol. 36, Issue 10 https://doi.org/10.1175/1520-0469(1979)036<2020:CSL>2.0.CO;2	journal	October 1979

Similar Records

Microtearing modes as the source of magnetic fluctuations in the JET pedestal

Journal Article · 2021 · Nuclear Fusion · OSTI ID:1849563

Hatch, D. R.; Kotschenreuther, M.; Mahajan, S. M.; +15 more

Gyrokinetic simulation of pedestal degradation correlated with enhanced magnetic turbulence in a DIII-D ELMy H-mode discharge

Journal Article · 2024 · Plasma Physics and Controlled Fusion · OSTI ID:2478400

Jian, X.; Chen, J.; Holland, C.; +4 more

Gyrokinetic analysis of inter-edge localized mode transport mechanisms in a DIII-D pedestal

Journal Article · 2022 · Physics of Plasmas · OSTI ID:2567850

Halfmoon, M. R.; Hatch, D. R.; Kotschenreuther, M. T.; +9 more

Title: Micro-tearing mode dominated electron heat transport in DIII-D H-mode pedestal

Citation Formats

References (37)

Similar Records

Related Subjects