H-mode transitions and limit cycle oscillations from mean field transport equations

Staebler, Gary M.; Groebner, Richard J.

doi:10.1088/0741-3335/57/1/014025

H-mode transitions and limit cycle oscillations from mean field transport equations

Journal Article · Fri Nov 28 00:00:00 EST 2014 · Plasma Physics and Controlled Fusion

DOI:https://doi.org/10.1088/0741-3335/57/1/014025· OSTI ID:1356339

Staebler, Gary M. ^[1]; Groebner, Richard J. ^[2]

General Atomics, San Diego, CA (United States); General Atomics
General Atomics, San Diego, CA (United States)

The mean field toroidal and parallel momentum transport equations will be shown to admit both onestep transitions to suppressed transport (L/H) and limit cycle oscillations (LCO). Both types of transitions are driven by the suppression of turbulence by the mean field ExB velocity shear. Using experimental data to evaluate the coefficients of a reduced transport model, the observed frequency of the LCO can be matched. The increase in the H-mode power threshold above and below a minimum density agrees with the trends in the model. Both leading and lagging phase relations between the turbulent density fluctuation amplitude and the ExB velocity shear can occur depending on the evolution of the linear growth rate of the turbulence. As a result, the transport solutions match the initial phase of the L/H transition where the poloidal and ExB velocities are observed to change, and the density fluctuations drop, faster than the diamagnetic velocity.

View Accepted Manuscript (DOE)

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

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

Grant/Contract Number:: FC02-04ER54698

OSTI ID:: 1356339

Alternate ID(s):: OSTI ID: 22362737

Journal Information:: Plasma Physics and Controlled Fusion, Journal Name: Plasma Physics and Controlled Fusion Journal Issue: 1 Vol. 57; ISSN 0741-3335

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (24)

Poloidal momentum transport due to drift-waves in toroidal geometry Staebler, G. M. Physics of Plasmas, Vol. 11, Issue 3 https://doi.org/10.1063/1.1647564	journal	March 2004
Parallel velocity shear instabilities in an inhomogeneous plasma with a sheared magnetic field Catto, Peter J. Physics of Fluids, Vol. 16, Issue 10 https://doi.org/10.1063/1.1694200	journal	January 1973
Gyro-Landau fluid equations for trapped and passing particles Staebler, G. M.; Kinsey, J. E.; Waltz, R. E. Physics of Plasmas, Vol. 12, Issue 10 https://doi.org/10.1063/1.2044587	journal	October 2005
Gyrokinetic theory and simulation of angular momentum transport Waltz, R. E.; Staebler, G. M.; Candy, J. Physics of Plasmas, Vol. 14, Issue 12 https://doi.org/10.1063/1.2824376	journal	December 2007
Modifications in turbulence and edge electric fields at the L–H transition in the DIII‐D tokamak Doyle, E. J.; Groebner, R. J.; Burrell, K. H. Physics of Fluids B: Plasma Physics, Vol. 3, Issue 8 https://doi.org/10.1063/1.859597	journal	August 1991
The effect of the radial electric field on the L–H transitions in tokamaks Rozhansky, V.; Tendler, M. Physics of Fluids B: Plasma Physics, Vol. 4, Issue 7 https://doi.org/10.1063/1.860463	journal	March 1992
Moment equation approach to neoclassical transport theory Hirshman, Steven P. Physics of Fluids, Vol. 21, Issue 2 https://doi.org/10.1063/1.862195	journal	January 1978
Nonlinear gyrokinetic equations for low-frequency electromagnetic waves in general plasma equilibria Frieman, E. A. Physics of Fluids, Vol. 25, Issue 3 https://doi.org/10.1063/1.863762	journal	January 1982
Neoclassical ion transport in rotating axisymmetric plasmas Hinton, F. L.; Wong, S. K. Physics of Fluids, Vol. 28, Issue 10 https://doi.org/10.1063/1.865350	journal	January 1985
Neoclassical quasilinear transport theory of fluctuations in toroidal plasmas Shaing, K. C. Physics of Fluids, Vol. 31, Issue 8 https://doi.org/10.1063/1.866626	journal	January 1988
Transport processes and entropy production in toroidally rotating plasmas with electrostatic turbulence Sugama, H.; Horton, W. Physics of Plasmas, Vol. 4, Issue 2 https://doi.org/10.1063/1.872099	journal	February 1997
Effects of E×B velocity shear and magnetic shear on turbulence and transport in magnetic confinement devices Burrell, K. H. Physics of Plasmas, Vol. 4, Issue 5 https://doi.org/10.1063/1.872367	journal	May 1997
Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio Houlberg, W. A.; Shaing, K. C.; Hirshman, S. P. Physics of Plasmas, Vol. 4, Issue 9 https://doi.org/10.1063/1.872465	journal	September 1997
Fluctuation level bursts in a model of internal transport barrier formation López-Bruna, D.; Newman, D. E.; Carreras, B. A. Physics of Plasmas, Vol. 6, Issue 3 https://doi.org/10.1063/1.873325	journal	March 1999
Drift wave based modelling of poloidal spin-up precursor and stepwise expansion of transport barriers Staebler, G. M.; Waltz, R. E.; Kinsey, J. E. Nuclear Fusion, Vol. 41, Issue 7 https://doi.org/10.1088/0029-5515/41/7/310	journal	July 2001
A new paradigm for E × B velocity shear suppression of gyro-kinetic turbulence and the momentum pinch Staebler, G. M.; Candy, J.; Waltz, R. E. Nuclear Fusion, Vol. 53, Issue 11 https://doi.org/10.1088/0029-5515/53/11/113017	journal	September 2013
Fuel ion rotation measurement and its implications on H-mode theories Kim, J.; Burrell, K. H.; Gohil, P. Plasma Physics and Controlled Fusion, Vol. 36, Issue 7A https://doi.org/10.1088/0741-3335/36/7A/025	journal	July 1994
Constraints on theories provided by fast time response measurements across the L to H transition on DIII-D Burrell, K. H.; Carlstrom, T. N.; Coda, S. Plasma Physics and Controlled Fusion, Vol. 38, Issue 8 https://doi.org/10.1088/0741-3335/38/8/028	journal	August 1996
Mean and Oscillating Plasma Flows and Turbulence Interactions across the L − H Confinement Transition Conway, G. D.; Angioni, C.; Ryter, F. Physical Review Letters, Vol. 106, Issue 6 https://doi.org/10.1103/PhysRevLett.106.065001	journal	February 2011
First Evidence of the Role of Zonal Flows for the L − H Transition at Marginal Input Power in the EAST Tokamak Xu, G. S.; Wan, B. N.; Wang, H. Q. Physical Review Letters, Vol. 107, Issue 12 https://doi.org/10.1103/PhysRevLett.107.125001	journal	September 2011
Role of Zonal Flow Predator-Prey Oscillations in Triggering the Transition to H-Mode Confinement Schmitz, L.; Zeng, L.; Rhodes, T. L. Physical Review Letters, Vol. 108, Issue 15 https://doi.org/10.1103/PhysRevLett.108.155002	journal	April 2012
New Paradigm for Suppression of Gyrokinetic Turbulence by Velocity Shear Staebler, G. M.; Waltz, R. E.; Candy, J. Physical Review Letters, Vol. 110, Issue 5 https://doi.org/10.1103/PhysRevLett.110.055003	journal	January 2013
Observation of the L − H Confinement Bifurcation Triggered by a Turbulence-Driven Shear Flow in a Tokamak Plasma Yan, Z.; McKee, G. R.; Fonck, R. Physical Review Letters, Vol. 112, Issue 12 https://doi.org/10.1103/PhysRevLett.112.125002	journal	March 2014
Bifurcation theory of poloidal rotation in tokamaks: A model for L-H transition Shaing, K.; Crume, E. Physical Review Letters, Vol. 63, Issue 21 https://doi.org/10.1103/PhysRevLett.63.2369	journal	November 1989

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Magnetic-confinement fusion Ongena, J.; Koch, R.; Wolf, R. Nature Physics, Vol. 12, Issue 5 https://doi.org/10.1038/nphys3745	journal	May 2016
H-mode access and the role of spectral shift with electrode biasing in the TCABR tokamak Grenfell, G. G.; Nascimento, I. C.; Oliveira, D. S. Physics of Plasmas, Vol. 25, Issue 7 https://doi.org/10.1063/1.5029561	journal	July 2018
Characteristics of an axisymmetric magnetic oscillation closely related to L-H transition on experimental advanced superconducting tokamak (EAST) Ye, K. X.; Zhang, T.; Xiang, H. M. Physics of Plasmas, Vol. 26, Issue 12 https://doi.org/10.1063/1.5119039	journal	December 2019
Stationary Zonal Flows during the Formation of the Edge Transport Barrier in the JET Tokamak Hillesheim, J. C.; Delabie, E.; Meyer, H. Physical Review Letters, Vol. 116, Issue 6 https://doi.org/10.1103/physrevlett.116.065002	journal	February 2016

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY
H-mode transitions
limit cycle oscillations
mean field transport

H-mode transitions and limit cycle oscillations from mean field transport equations

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References (24)

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