Impact of edge harmonic oscillations on the divertor heat flux in NSTX

Gan, K. F.; Gray, T. K.; Zweben, S. J.; Fredrickson, E. D.; Maingi, R.; Battaglia, D. J.; McLean, A. G.; Wirth, B. D.

doi:10.1063/5.0069701

Impact of edge harmonic oscillations on the divertor heat flux in NSTX

Journal Article · Wed Jan 12 23:00:00 EST 2022 · Physics of Plasmas

DOI:https://doi.org/10.1063/5.0069701· OSTI ID:1839915

^[1]; ^[2]; ^[3]; ^[3]; ^[3]; ^[3]; McLean, A. G. ^[4]; ^[5]

University of Tennessee, Knoxville, TN (United States); University of Tennessee, Knoxville
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
University of Tennessee, Knoxville, TN (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Previously, ELM-free and inter-ELM divertor peak heat flux reduction induced by an edge harmonic oscillation (EHO) was observed in NSTX (K.F. Gan et al., 2017 Nucl. Fusion 57 126053). This paper introduces new analysis of the EHO impact on the divertor heat flux. It was found that enhanced edge turbulence significantly altered the divertor heat flux footprint in NSTX H-modes, relative to ELM-free discharges. When the background edge fluctuation level was low, the EHO significantly increased the heat flux width and decreased the divertor peak heat flux. When the background edge fluctuation level was high, the EHO actually increased the divertor peak heat flux. As a result, it was also found that the heat flux width increased with increasing frequency of the EHO.

View Accepted Manuscript (DOE)

Research Organization:: University of Tennessee, Knoxville, TN (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: SC0016915; AC05-00OR22725

OSTI ID:: 1839915

Alternate ID(s):: OSTI ID: 1839848
OSTI ID: 1860571

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 1 Vol. 29; ISSN 1070-664X

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

Country of Publication:: United States

Language:: English

References (23)

Impact of edge harmonic oscillations on the divertor heat flux in NSTX Gan, Kaifu; Gray, Travis; Zweben, Stewart Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1888267	dataset	January 2021
Multi-machine scaling of the divertor peak heat flux and width for L-mode and H-mode discharges Loarte, A.; Bosch, S.; Chankin, A. Journal of Nuclear Materials, Vol. 266-269 https://doi.org/10.1016/S0022-3115(98)00590-X	journal	March 1999
2D heat flux in ASDEX Upgrade L-Mode with magnetic perturbation Faitsch, M.; Sieglin, B.; Eich, T. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2017.03.008	journal	August 2017
Physics basis for the first ITER tungsten divertor Pitts, R. A.; Bonnin, X.; Escourbiac, F. Nuclear Materials and Energy, Vol. 20 https://doi.org/10.1016/j.nme.2019.100696	journal	August 2019
Overview of the SPARC tokamak Creely, A. J.; Greenwald, M. J.; Ballinger, S. B. Journal of Plasma Physics, Vol. 86, Issue 5 https://doi.org/10.1017/S0022377820001257	journal	September 2020
High speed infrared camera diagnostic for heat flux measurement in NSTX Ahn, J. -W.; Maingi, R.; Mastrovito, D. Review of Scientific Instruments, Vol. 81, Issue 2 https://doi.org/10.1063/1.3297899	journal	February 2010
Quiet periods in edge turbulence preceding the L-H transition in the National Spherical Torus Experiment Zweben, S. J.; Maqueda, R. J.; Hager, R. Physics of Plasmas, Vol. 17, Issue 10 https://doi.org/10.1063/1.3476276	journal	October 2010
2D divertor heat flux distribution using a 3D heat conduction solver in National Spherical Torus Experiment Gan, K. F.; Ahn, J-W.; Park, J. -W. Review of Scientific Instruments, Vol. 84, Issue 2 https://doi.org/10.1063/1.4792595	journal	February 2013
MHD-blob correlations in NSTX Zweben, S. J.; Fredrickson, E. D.; Myra, J. R. Physics of Plasmas, Vol. 27, Issue 5 https://doi.org/10.1063/5.0006515	journal	May 2020
Enhanced pedestal H-mode at low edge ion collisionality on NSTX Battaglia, D. J.; Guttenfelder, W.; Bell, R. E. Physics of Plasmas, Vol. 27, Issue 7 https://doi.org/10.1063/5.0011614	journal	July 2020
Edge pedestal control in quiescent H-mode discharges in DIII-D using co-plus counter-neutral beam injection Burrell, K. H.; Osborne, T. H.; Snyder, P. B. Nuclear Fusion, Vol. 49, Issue 8 https://doi.org/10.1088/0029-5515/49/8/085024	journal	July 2009
Pedestal characterization and stability of small-ELM regimes in NSTX Sontag, A. C.; Canik, J. M.; Maingi, R. Nuclear Fusion, Vol. 51, Issue 10 https://doi.org/10.1088/0029-5515/51/10/103022	journal	September 2011
Overview of the physics and engineering design of NSTX upgrade Menard, J. E.; Gerhardt, S.; Bell, M. Nuclear Fusion, Vol. 52, Issue 8 https://doi.org/10.1088/0029-5515/52/8/083015	journal	July 2012
Scaling of the tokamak near the scrape-off layer H-mode power width and implications for ITER Eich, T.; Leonard, A. W.; Pitts, R. A. Nuclear Fusion, Vol. 53, Issue 9 https://doi.org/10.1088/0029-5515/53/9/093031	journal	August 2013
Dynamics of L–H transition and I-phase in EAST Xu, G. S.; Wang, H. Q.; Xu, M. Nuclear Fusion, Vol. 54, Issue 10 https://doi.org/10.1088/0029-5515/54/10/103002	journal	September 2014
Observation of EHO in NSTX and theoretical study of its active control using HHFW antenna Park, J. -K.; Goldston, R. J.; Crocker, N. A. Nuclear Fusion, Vol. 54, Issue 4 https://doi.org/10.1088/0029-5515/54/4/043013	journal	March 2014
Progress toward commissioning and plasma operation in NSTX-U Ono, M.; Chrzanowski, J.; Dudek, L. Nuclear Fusion, Vol. 55, Issue 7 https://doi.org/10.1088/0029-5515/55/7/073007	journal	June 2015
Physics of the L-mode to H-mode transition in tokamaks Burrell, K. H.; Carlstrom, T. N.; Doyle, E. J. Plasma Physics and Controlled Fusion, Vol. 34, Issue 13 https://doi.org/10.1088/0741-3335/34/13/014	journal	December 1992
Suppression of the edge turbulence at the L-H transition in DIII-D Matsumoto, H.; Burrell, K. H.; Carlstrom, T. M. Plasma Physics and Controlled Fusion, Vol. 34, Issue 4 https://doi.org/10.1088/0741-3335/34/4/018	journal	April 1992
Energy exchange dynamics across L–H transitions in NSTX Diallo, A.; Banerjee, S.; Zweben, S. J. Nuclear Fusion, Vol. 57, Issue 6 https://doi.org/10.1088/1741-4326/aa6a24	journal	May 2017
Gyrokinetic projection of the divertor heat-flux width from present tokamaks to ITER Chang, C. S.; Ku, S.; Loarte, A. Nuclear Fusion, Vol. 57, Issue 11 https://doi.org/10.1088/1741-4326/aa7efb	journal	August 2017
ELM-free and inter-ELM divertor heat flux broadening induced by edge harmonics oscillation in NSTX Gan, K. F.; Ahn, J. -W.; Gray, T. K. Nuclear Fusion, Vol. 57, Issue 12 https://doi.org/10.1088/1741-4326/aa8c4a	journal	October 2017
Inter-ELM Power Decay Length for JET and ASDEX Upgrade: Measurement and Comparison with Heuristic Drift-Based Model Eich, T.; Sieglin, B.; Scarabosio, A. Physical Review Letters, Vol. 107, Issue 21 https://doi.org/10.1103/PhysRevLett.107.215001	journal	November 2011

Cited By (1)

Impact of edge harmonic oscillations on the divertor heat flux in NSTX Gan, Kaifu; Gray, Travis; Zweben, Stewart Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1888267	dataset	January 2021

Similar Records

ELM-free and inter-ELM divertor heat flux broadening induced by Edge Harmonics Oscillation in NSTX

Dataset · Thu Nov 30 23:00:00 EST 2017 · OSTI ID:1562042

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
divertor heat flux
edge harmonics oscillation
magnetohydrodynamics
plasma confinement
thermography
tokamaks

Impact of edge harmonic oscillations on the divertor heat flux in NSTX

Citation Formats

References (23)

Cited By (1)

Similar Records

Related Subjects