Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes

Bass, Eric M.; Waltz, R. E.

doi:10.1063/1.4998420

Title: Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes

Abstract

Here, a “stiff transport” critical gradient model of energetic particle (EP) transport by EPdriven Alfven eigenmodes (AEs) is verified against local nonlinear gyrokinetic simulations of a well-studied beam-heated DIII-D discharge 146102. A greatly simplifying linear “recipe” for the limiting EP-density gradient (critical gradient) is considered here. In this recipe, the critical gradient occurs when the AE linear growth rate, driven mainly by the EP gradient, exceeds the ion temperature gradient (ITG) or trapped electron mode (TEM) growth rate, driven by the thermal plasma gradient, at the same toroidal mode number (n) as the AE peak growth, well below the ITG/TEM peak n. This linear recipe for the critical gradient is validated against the critical gradient determined from far more expensive local nonlinear simulations in the gyrokinetic code GYRO, as identified by the point of transport runaway when all driving gradients are held fixed. The reduced linear model is extended to include the stabilization from equilibrium E×B velocity shear. The nonlinear verification unambiguously endorses one of two alternative recipes proposed in Ref. 1: the EP-driven AE growth rate should be determined with rather than without added thermal plasma drive.

Authors:

Bass, Eric M. ^[1];

^[2]

Univ. of California, San Diego, CA (United States)
General Atomics, San Diego, CA (United States)

Publication Date:: Fri Dec 08 00:00:00 EST 2017

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

Sponsoring Org.:: USDOE Office of Nuclear Energy (NE)

OSTI Identifier:: 1438438

Alternate Identifier(s):: OSTI ID: 1411993

Grant/Contract Number:: FG02-95ER54309; FC02-08ER54977

Resource Type:: Accepted Manuscript

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 24; Journal Issue: 12; Journal ID: ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats


                    Bass, Eric M., and Waltz, R. E. Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes.  United States: N. p., 2017. 
Web.  doi:10.1063/1.4998420.

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                    Bass, Eric M., & Waltz, R. E. Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes.  United States.  https://doi.org/10.1063/1.4998420

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                    Bass, Eric M., and Waltz, R. E. Fri .  
"Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes".  United States.  https://doi.org/10.1063/1.4998420.  https://www.osti.gov/servlets/purl/1438438.

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@article{osti_1438438,

  title        = {Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes},

  author       = {Bass, Eric M. and Waltz, R. E.},

  abstractNote = {Here, a “stiff transport” critical gradient model of energetic particle (EP) transport by EPdriven Alfven eigenmodes (AEs) is verified against local nonlinear gyrokinetic simulations of a well-studied beam-heated DIII-D discharge 146102. A greatly simplifying linear “recipe” for the limiting EP-density gradient (critical gradient) is considered here. In this recipe, the critical gradient occurs when the AE linear growth rate, driven mainly by the EP gradient, exceeds the ion temperature gradient (ITG) or trapped electron mode (TEM) growth rate, driven by the thermal plasma gradient, at the same toroidal mode number (n) as the AE peak growth, well below the ITG/TEM peak n. This linear recipe for the critical gradient is validated against the critical gradient determined from far more expensive local nonlinear simulations in the gyrokinetic code GYRO, as identified by the point of transport runaway when all driving gradients are held fixed. The reduced linear model is extended to include the stabilization from equilibrium E×B velocity shear. The nonlinear verification unambiguously endorses one of two alternative recipes proposed in Ref. 1: the EP-driven AE growth rate should be determined with rather than without added thermal plasma drive.},

  doi          = {10.1063/1.4998420},

  journal      = {Physics of Plasmas},

  number       = 12,

  volume       = 24,

  place        = {United States},

  year         = {Fri Dec 08 00:00:00 EST 2017},

  month        = {Fri Dec 08 00:00:00 EST 2017}

}

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Works referenced in this record:

Toroidal gyro‐Landau fluid model turbulence simulations in a nonlinear ballooning mode representation with radial modes
journal, July 1994

Waltz, R. E.; Kerbel, G. D.; Milovich, J.
Physics of Plasmas, Vol. 1, Issue 7
DOI: 10.1063/1.870934

1.5D quasilinear model and its application on beams interacting with Alfvén eigenmodes in DIII-D
journal, September 2012

Ghantous, K.; Gorelenkov, N. N.; Berk, H. L.
Physics of Plasmas, Vol. 19, Issue 9
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An Eulerian gyrokinetic-Maxwell solver
journal, April 2003

Candy, J.; Waltz, R. E.
Journal of Computational Physics, Vol. 186, Issue 2
DOI: 10.1016/S0021-9991(03)00079-2

Kinetic transport simulation of energetic particles
journal, April 2016

Sheng, He; Waltz, R. E.
Nuclear Fusion, Vol. 56, Issue 5
DOI: 10.1088/0029-5515/56/5/056004

Anomalous momentum transport from drift wave turbulence
journal, November 1993

Dominguez, R. R.; Staebler, G. M.
Physics of Fluids B: Plasma Physics, Vol. 5, Issue 11
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Gyrokinetic simulations of impurity, He ash and α particle transport and consequences on ITER transport modelling
journal, April 2009

Angioni, C.; Peeters, A. G.; Pereverzev, G. V.
Nuclear Fusion, Vol. 49, Issue 5
DOI: 10.1088/0029-5515/49/5/055013

Anomalous Transport Scaling in the DIII-D Tokamak Matched by Supercomputer Simulation
journal, July 2003

Candy, J.; Waltz, R. E.
Physical Review Letters, Vol. 91, Issue 4
DOI: 10.1103/PhysRevLett.91.045001

Alfvén eigenmode stability and critical gradient energetic particle transport using the Trapped-Gyro-Landau-Fluid model
journal, July 2017

Sheng, He; Waltz, R. E.; Staebler, G. M.
Physics of Plasmas, Vol. 24, Issue 7
DOI: 10.1063/1.4989716

Prediction of the fusion alpha density profile in ITER from local marginal stability to Alfvén eigenmodes
journal, October 2014

Waltz, R. E.; Bass, E. M.
Nuclear Fusion, Vol. 54, Issue 10
DOI: 10.1088/0029-5515/54/10/104006

Ion temperature gradient turbulence simulations and plasma flux surface shape
journal, November 1999

Waltz, R. E.; Miller, R. L.
Physics of Plasmas, Vol. 6, Issue 11
DOI: 10.1063/1.873694

Gyrokinetic simulations of mesoscale energetic particle-driven Alfvénic turbulent transport embedded in microturbulence
journal, November 2010

Bass, E. M.; Waltz, R. E.
Physics of Plasmas, Vol. 17, Issue 11
DOI: 10.1063/1.3509106

Gyrokinetic calculations of diffusive and convective transport of α particles with a slowing-down distribution function
journal, May 2008

Angioni, C.; Peeters, A. G.
Physics of Plasmas, Vol. 15, Issue 5
DOI: 10.1063/1.2913610

Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments
journal, October 2015

Waltz, R. E.; Bass, E. M.; Heidbrink, W. W.
Nuclear Fusion, Vol. 55, Issue 12
DOI: 10.1088/0029-5515/55/12/123012

Gyrokinetic simulation of global and local Alfvén eigenmodes driven by energetic particles in a DIII-D discharge
journal, January 2013

Bass, E. M.; Waltz, R. E.
Physics of Plasmas, Vol. 20, Issue 1
DOI: 10.1063/1.4773177

A theory-based transport model with comprehensive physics
journal, May 2007

Staebler, G. M.; Kinsey, J. E.; Waltz, R. E.
Physics of Plasmas, Vol. 14, Issue 5
DOI: 10.1063/1.2436852

The effect of the fast-ion profile on Alfvén eigenmode stability
journal, August 2013

Heidbrink, W. W.; Van Zeeland, M. A.; Austin, M. E.
Nuclear Fusion, Vol. 53, Issue 9
DOI: 10.1088/0029-5515/53/9/093006

Theory and simulation of rotational shear stabilization of turbulence
journal, May 1998

Waltz, R. E.; Dewar, R. L.; Garbet, X.
Physics of Plasmas, Vol. 5, Issue 5
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Gyro-Landau fluid equations for trapped and passing particles
journal, October 2005

Staebler, G. M.; Kinsey, J. E.; Waltz, R. E.
Physics of Plasmas, Vol. 12, Issue 10
DOI: 10.1063/1.2044587

Energetic particle physics in fusion research in preparation for burning plasma experiments
journal, November 2014

Gorelenkov, N. N.; Pinches, S. D.; Toi, K.
Nuclear Fusion, Vol. 54, Issue 12
DOI: 10.1088/0029-5515/54/12/125001

Works referencing / citing this record:

Verification and validation of integrated simulation of energetic particles in fusion plasmas
journal, April 2019

Taimourzadeh, S.; Bass, E. M.; Chen, Y.
Nuclear Fusion, Vol. 59, Issue 6
DOI: 10.1088/1741-4326/ab0c38

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Title: Nonlinear verification of a linear critical gradient model for energetic particle transport by Alfven eigenmodes

Abstract

Citation Formats

Toroidal gyro‐Landau fluid model turbulence simulations in a nonlinear ballooning mode representation with radial modes journal, July 1994

1.5D quasilinear model and its application on beams interacting with Alfvén eigenmodes in DIII-D journal, September 2012

An Eulerian gyrokinetic-Maxwell solver journal, April 2003

Kinetic transport simulation of energetic particles journal, April 2016

Anomalous momentum transport from drift wave turbulence journal, November 1993

Gyrokinetic simulations of impurity, He ash and α particle transport and consequences on ITER transport modelling journal, April 2009

Anomalous Transport Scaling in the DIII-D Tokamak Matched by Supercomputer Simulation journal, July 2003

Alfvén eigenmode stability and critical gradient energetic particle transport using the Trapped-Gyro-Landau-Fluid model journal, July 2017

Prediction of the fusion alpha density profile in ITER from local marginal stability to Alfvén eigenmodes journal, October 2014

Ion temperature gradient turbulence simulations and plasma flux surface shape journal, November 1999

Gyrokinetic simulations of mesoscale energetic particle-driven Alfvénic turbulent transport embedded in microturbulence journal, November 2010

Gyrokinetic calculations of diffusive and convective transport of α particles with a slowing-down distribution function journal, May 2008

Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments journal, October 2015

Gyrokinetic simulation of global and local Alfvén eigenmodes driven by energetic particles in a DIII-D discharge journal, January 2013

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The effect of the fast-ion profile on Alfvén eigenmode stability journal, August 2013

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Energetic particle physics in fusion research in preparation for burning plasma experiments journal, November 2014

Verification and validation of integrated simulation of energetic particles in fusion plasmas journal, April 2019

Toroidal gyro‐Landau fluid model turbulence simulations in a nonlinear ballooning mode representation with radial modes
journal, July 1994

1.5D quasilinear model and its application on beams interacting with Alfvén eigenmodes in DIII-D
journal, September 2012

An Eulerian gyrokinetic-Maxwell solver
journal, April 2003

Kinetic transport simulation of energetic particles
journal, April 2016

Anomalous momentum transport from drift wave turbulence
journal, November 1993

Gyrokinetic simulations of impurity, He ash and α particle transport and consequences on ITER transport modelling
journal, April 2009

Anomalous Transport Scaling in the DIII-D Tokamak Matched by Supercomputer Simulation
journal, July 2003

Alfvén eigenmode stability and critical gradient energetic particle transport using the Trapped-Gyro-Landau-Fluid model
journal, July 2017

Prediction of the fusion alpha density profile in ITER from local marginal stability to Alfvén eigenmodes
journal, October 2014

Ion temperature gradient turbulence simulations and plasma flux surface shape
journal, November 1999

Gyrokinetic simulations of mesoscale energetic particle-driven Alfvénic turbulent transport embedded in microturbulence
journal, November 2010

Gyrokinetic calculations of diffusive and convective transport of α particles with a slowing-down distribution function
journal, May 2008

Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments
journal, October 2015

Gyrokinetic simulation of global and local Alfvén eigenmodes driven by energetic particles in a DIII-D discharge
journal, January 2013

A theory-based transport model with comprehensive physics
journal, May 2007

The effect of the fast-ion profile on Alfvén eigenmode stability
journal, August 2013

Theory and simulation of rotational shear stabilization of turbulence
journal, May 1998

Gyro-Landau fluid equations for trapped and passing particles
journal, October 2005

Energetic particle physics in fusion research in preparation for burning plasma experiments
journal, November 2014

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