Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling

Xu, X. Q.; Ma, J. F.; Li, G. Q.

doi:10.1063/1.4905070

Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling

Journal Article · Mon Dec 29 00:00:00 EST 2014 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4905070· OSTI ID:1258542

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Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Texas, Austin, TX (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chinese Academy of Sciences, Hefei (China)

The latest BOUT++ studies show an emerging understanding of dynamics of edge localized mode(ELM) crashes and the consistent collisionality scaling of ELMenergy losses with the world multi-tokamak database. A series of BOUT++ simulations are conducted to investigate the scaling characteristics of the ELMenergy losses vs collisionality via a density scan. Moreover, the linear results demonstrate that as the pedestal collisionality decreases, the growth rate of the peeling-ballooning modes decreases for high n but increases for low n (1 < n < 5), therefore the width of the growth rate spectrum γ(n) becomes narrower and the peak growth shifts to lower n. For nonlinear BOUT++ simulations show a two-stage process of ELM crash evolution of (i) initial bursts of pressure blob and void creation and (ii) inward void propagation. The inward void propagation stirs the top of pedestal plasma and yields an increasing ELM size with decreasing collisionality after a series of micro-bursts. The pedestal plasma density plays a major role in determining the ELMenergy loss through its effect on the edge bootstrap current and ion diamagnetic stabilization. Finally, the critical trend emerges as a transition (1) linearly from ballooning-dominated states at high collisionality to peeling-dominated states at low collisionality with decreasing density and (2) nonlinearly from turbulence spreading dynamics at high collisionality into avalanche-like dynamics at low collisionality.

View Accepted Manuscript (DOE)

Research Organization:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC52-07NA27344; FG02-04ER54742

OSTI ID:: 1258542

Alternate ID(s):: OSTI ID: 1226641
OSTI ID: 22403314

Report Number(s):: LLNL-JRNL--656259

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 21; ISSN PHPAEN; ISSN 1070-664X

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

Country of Publication:: United States

Language:: English

References (16)

BOUT++: A framework for parallel plasma fluid simulations Dudson, B. D.; Umansky, M. V.; Xu, X. Q. Computer Physics Communications, Vol. 180, Issue 9 https://doi.org/10.1016/j.cpc.2009.03.008	journal	September 2009
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
Erratum: “Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime” [Phys. Plasmas 6 , 2834 (1999)] Sauter, O.; Angioni, C.; Lin-Liu, Y. R. Physics of Plasmas, Vol. 9, Issue 12 https://doi.org/10.1063/1.1517052	journal	December 2002
Gyro-fluid and two-fluid theory and simulations of edge-localized-modes Xu, X. Q.; Xi, P. W.; Dimits, A. Physics of Plasmas, Vol. 20, Issue 5 https://doi.org/10.1063/1.4801746	journal	May 2013
Edge-localized-modes in tokamaks Leonard, A. W. Physics of Plasmas, Vol. 21, Issue 9 https://doi.org/10.1063/1.4894742	journal	September 2014
Linear calculations of edge current driven kink modes with BOUT++ code Li, G. Q.; Xu, X. Q.; Snyder, P. B. Physics of Plasmas, Vol. 21, Issue 10 https://doi.org/10.1063/1.4898673	journal	October 2014
Impact of relative phase shift on inward turbulent spreading Ma, C. H.; Xu, X. Q.; Xi, P. W. Physics of Plasmas, Vol. 22, Issue 1 https://doi.org/10.1063/1.4905644	journal	January 2015
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime Sauter, O.; Angioni, C.; Lin-Liu, Y. R. Physics of Plasmas, Vol. 6, Issue 7 https://doi.org/10.1063/1.873240	journal	July 1999
Low-to-high confinement transition simulations in divertor geometry Xu, X. Q.; Cohen, R. H.; Rognlien, T. D. Physics of Plasmas, Vol. 7, Issue 5 https://doi.org/10.1063/1.874044	journal	May 2000
Characterization of the density profile collapse of type I ELMs in ASDEX Upgrade with high temporal and spatial resolution reflectometry Nunes, I.; Conway, G. D.; Loarte, A. Nuclear Fusion, Vol. 44, Issue 8 https://doi.org/10.1088/0029-5515/44/8/007	journal	July 2004
Nonlinear ELM simulations based on a nonideal peeling–ballooning model using the BOUT++ code Xu, X. Q.; Dudson, B. D.; Snyder, P. B. Nuclear Fusion, Vol. 51, Issue 10 https://doi.org/10.1088/0029-5515/51/10/103040	journal	September 2011
Six-field two-fluid simulations of peeling–ballooning modes using BOUT++ Xia, T. Y.; Xu, X. Q.; Xi, P. W. Nuclear Fusion, Vol. 53, Issue 7 https://doi.org/10.1088/0029-5515/53/7/073009	journal	May 2013
The physics of edge localized modes (ELMs) and their role in power and particle exhaust Zohm, Hartmut Plasma Physics and Controlled Fusion, Vol. 38, Issue 8 https://doi.org/10.1088/0741-3335/38/8/012	journal	August 1996
Characteristics of type I ELM energy and particle losses in existing devices and their extrapolation to ITER Loarte, A.; Saibene, G.; Sartori, R. Plasma Physics and Controlled Fusion, Vol. 45, Issue 9 https://doi.org/10.1088/0741-3335/45/9/302	journal	August 2003
Nonlinear Simulations of Peeling-Ballooning Modes with Anomalous Electron Viscosity and their Role in Edge Localized Mode Crashes Xu, X. Q.; Dudson, B.; Snyder, P. B. Physical Review Letters, Vol. 105, Issue 17 https://doi.org/10.1103/PhysRevLett.105.175005	journal	October 2010
Phase Dynamics Criterion for Fast Relaxation of High-Confinement-Mode Plasmas Xi, P. W.; Xu, X. Q.; Diamond, P. H. Physical Review Letters, Vol. 112, Issue 8 https://doi.org/10.1103/PhysRevLett.112.085001	journal	February 2014

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Impact of inward turbulence spreading on energy loss of edge-localized modesa) Ma, C. H.; Xu, X. Q.; Xi, P. W. Physics of Plasmas, Vol. 22, Issue 5 https://doi.org/10.1063/1.4920963	journal	May 2015
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Self-driven current generation in turbulent fusion plasmas Wang, W. X.; Hahm, T. S.; Startsev, E. A. Nuclear Fusion, Vol. 59, Issue 8 https://doi.org/10.1088/1741-4326/ab266d	journal	June 2019

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