skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Validation study of GENE on ASDEX Upgrade using perturbative thermal diffusivity measured with partial sawtooth heat pulses

Abstract

Perturbative thermal diffusivity is measured with partial sawtooth-generated heat pulses on ASDEX Upgrade for the first time, and these measurements are used to validate the first nonlinear ion-scale gyrokinetic simulation that agrees with experimentally measured perturbative diffusivity. Recent work on Alcator C-Mod (Howard et al 2016 Phys. Plasmas 23 056109) and DIII-D (Holland et al 2017 Nucl. Fusion 57 066043) has shown that ion-scale gyrokinetics cannot adequately describe certain plasma conditions, and that in these instances multi-scale simulations may resolve the observed discrepancies. This work presents the first measurements of electron perturbative thermal diffusivity with partial sawteeth on ASDEX Upgrade (measuring values between 2 and 9 m2 s−1), and compares these measurements to those made with more established modulated electron cyclotron heating measurements, finding good agreement within experimental uncertainty. Perturbative diffusivity is found to scale inversely with collisionality across ASDEX Upgrade and Alcator C-Mod plasmas. Finally, perturbative diffusivity is used as a validation constraint in a study with the gyrokinetic code GENE, showing the first instance where an ion-scale gyrokinetic simulation can simultaneously match the experimental ion and electron heat fluxes and the perturbative thermal diffusivity. These results indicate that multi-scale effects may only be important in some plasmas, andmore » the collisionality and ratio of high to low wavenumber linear growth rates may distinguish these cases.« less

Authors:
ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
Contributing Org.:
The ASDEX Upgrade Team
OSTI Identifier:
1543948
DOE Contract Number:  
FC02-99ER54512; SC0006419; SC0017381
Resource Type:
Journal Article
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 12; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
Physics

Citation Formats

Creely, A. J., Görler, T., Conway, G. D., Freethy, S. J., Howard, N. T., Schneider, P. A., White, A. E., and Willensdorfer, M. Validation study of GENE on ASDEX Upgrade using perturbative thermal diffusivity measured with partial sawtooth heat pulses. United States: N. p., 2018. Web. doi:10.1088/1741-4326/aadca1.
Creely, A. J., Görler, T., Conway, G. D., Freethy, S. J., Howard, N. T., Schneider, P. A., White, A. E., & Willensdorfer, M. Validation study of GENE on ASDEX Upgrade using perturbative thermal diffusivity measured with partial sawtooth heat pulses. United States. doi:10.1088/1741-4326/aadca1.
Creely, A. J., Görler, T., Conway, G. D., Freethy, S. J., Howard, N. T., Schneider, P. A., White, A. E., and Willensdorfer, M. Fri . "Validation study of GENE on ASDEX Upgrade using perturbative thermal diffusivity measured with partial sawtooth heat pulses". United States. doi:10.1088/1741-4326/aadca1.
@article{osti_1543948,
title = {Validation study of GENE on ASDEX Upgrade using perturbative thermal diffusivity measured with partial sawtooth heat pulses},
author = {Creely, A. J. and Görler, T. and Conway, G. D. and Freethy, S. J. and Howard, N. T. and Schneider, P. A. and White, A. E. and Willensdorfer, M.},
abstractNote = {Perturbative thermal diffusivity is measured with partial sawtooth-generated heat pulses on ASDEX Upgrade for the first time, and these measurements are used to validate the first nonlinear ion-scale gyrokinetic simulation that agrees with experimentally measured perturbative diffusivity. Recent work on Alcator C-Mod (Howard et al 2016 Phys. Plasmas 23 056109) and DIII-D (Holland et al 2017 Nucl. Fusion 57 066043) has shown that ion-scale gyrokinetics cannot adequately describe certain plasma conditions, and that in these instances multi-scale simulations may resolve the observed discrepancies. This work presents the first measurements of electron perturbative thermal diffusivity with partial sawteeth on ASDEX Upgrade (measuring values between 2 and 9 m2 s−1), and compares these measurements to those made with more established modulated electron cyclotron heating measurements, finding good agreement within experimental uncertainty. Perturbative diffusivity is found to scale inversely with collisionality across ASDEX Upgrade and Alcator C-Mod plasmas. Finally, perturbative diffusivity is used as a validation constraint in a study with the gyrokinetic code GENE, showing the first instance where an ion-scale gyrokinetic simulation can simultaneously match the experimental ion and electron heat fluxes and the perturbative thermal diffusivity. These results indicate that multi-scale effects may only be important in some plasmas, and the collisionality and ratio of high to low wavenumber linear growth rates may distinguish these cases.},
doi = {10.1088/1741-4326/aadca1},
journal = {Nuclear Fusion},
issn = {0029-5515},
number = 12,
volume = 58,
place = {United States},
year = {2018},
month = {9}
}

Works referenced in this record:

Electron temperature gradient driven turbulence
journal, May 2000

  • Jenko, F.; Dorland, W.; Kotschenreuther, M.
  • Physics of Plasmas, Vol. 7, Issue 5
  • DOI: 10.1063/1.874014

Verification and validation for magnetic fusion
journal, May 2010


Validation metrics for turbulent plasma transport
journal, June 2016


Perturbative thermal diffusivity from partial sawtooth crashes in Alcator C-Mod
journal, February 2016


Multi-scale gyrokinetic simulation of tokamak plasmas: enhanced heat loss due to cross-scale coupling of plasma turbulence
journal, December 2015


Validation of nonlinear gyrokinetic simulations of L- and I-mode plasmas on Alcator C-Mod
journal, May 2017

  • Creely, A. J.; Howard, N. T.; Rodriguez-Fernandez, P.
  • Physics of Plasmas, Vol. 24, Issue 5
  • DOI: 10.1063/1.4977466

Multi-scale gyrokinetic simulations of an Alcator C-Mod, ELM-y H-mode plasma
journal, November 2017

  • Howard, N. T.; Holland, C.; White, A. E.
  • Plasma Physics and Controlled Fusion, Vol. 60, Issue 1
  • DOI: 10.1088/1361-6587/aa9148

Perturbative transport studies in fusion plasmas
journal, August 1995


Transport Studies Using Perturbative Experiments
journal, February 2010


Nonlinear Stabilization of Tokamak Microturbulence by Fast Ions
journal, October 2013


Multi-scale gyrokinetic simulations: Comparison with experiment and implications for predicting turbulence and transport
journal, April 2016

  • Howard, N. T.; Holland, C.; White, A. E.
  • Physics of Plasmas, Vol. 23, Issue 5
  • DOI: 10.1063/1.4946028

Gyrokinetic predictions of multiscale transport in a DIII-D ITER baseline discharge
journal, May 2017


Plasma response measurements of external magnetic perturbations using electron cyclotron emission and comparisons to 3D ideal MHD equilibrium
journal, September 2016


Heat pulse propagation studies on DIII-D and the Tokamak Fusion Test Reactor
journal, December 2000

  • Fredrickson, E. D.; Austin, M. E.; Groebner, R.
  • Physics of Plasmas, Vol. 7, Issue 12
  • DOI: 10.1063/1.1319335

Sawtooth heat pulse propagation in tokamaks: Ballistic response and Fourier analysis
journal, July 1996


Tokamak heat transport – a study of heat pulse propagation in JET
journal, November 1987


Heat pulse propagation: Diffusive models checked against full transport calculations
journal, July 1988


Measurement of local ion diffusion coefficients in the Tokamak Fusion Test Reactor
journal, January 1999


Experimental Evidence for Gradient Length-Driven Electron Transport in Tokamaks
journal, March 2001


Electron heat transport in ASDEX Upgrade: experiment and modelling
journal, November 2003


Perturbative studies of transport phenomena in fusion devices
journal, November 2010


Simultaneous analysis of ion and electron heat transport by power modulation in JET
journal, October 2011


Electron profile stiffness and critical gradient studies
journal, August 2012

  • DeBoo, J. C.; Petty, C. C.; White, A. E.
  • Physics of Plasmas, Vol. 19, Issue 8
  • DOI: 10.1063/1.4750061

Explaining the isotope effect on heat transport in L-mode with the collisional electron-ion energy exchange
journal, April 2017


Determination of diffusive and nondiffusive transport in modulation experiments in plasmas
journal, November 1991

  • Jacchia, A.; Mantica, P.; De Luca, F.
  • Physics of Fluids B: Plasma Physics, Vol. 3, Issue 11
  • DOI: 10.1063/1.859781

Fourier analysis of sawtooth heat pulse propagation and comparison with other methods using JET data
journal, December 1992


Characterizing turbulent transport in ASDEX Upgrade L-mode plasmas via nonlinear gyrokinetic simulations
journal, December 2013

  • Told, D.; Jenko, F.; Görler, T.
  • Physics of Plasmas, Vol. 20, Issue 12
  • DOI: 10.1063/1.4858899

Collisionality dependence of density peaking in quasilinear gyrokinetic calculations
journal, November 2005

  • Angioni, C.; Peeters, A. G.; Jenko, F.
  • Physics of Plasmas, Vol. 12, Issue 11
  • DOI: 10.1063/1.2135283

Experimental Study of Trapped-Electron-Mode Properties in Tokamaks: Threshold and Stabilization by Collisions
journal, August 2005


Analytical solutions to the Grad–Shafranov equation for tokamak equilibrium with dissimilar source functions
journal, September 1999


The Thomson scattering systems of the ASDEX upgrade tokamak
journal, October 1992

  • Murmann, H.; Götsch, S.; Röhr, H.
  • Review of Scientific Instruments, Vol. 63, Issue 10
  • DOI: 10.1063/1.1143504

Edge and core Thomson scattering systems and their calibration on the ASDEX Upgrade tokamak
journal, October 2011

  • Kurzan, B.; Murmann, H. D.
  • Review of Scientific Instruments, Vol. 82, Issue 10
  • DOI: 10.1063/1.3643771

High-resolution charge exchange measurements at ASDEX Upgrade
journal, October 2012

  • Viezzer, E.; Pütterich, T.; Dux, R.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4755810

Simulations of deuterium-tritium experiments in TFTR
journal, March 1992


Uncertainty estimation and a stopping rule in nonlinear gyrokinetic simulations
journal, November 2016


An Eulerian gyrokinetic-Maxwell solver
journal, April 2003


20 years of research on the Alcator C-Mod tokamaka)
journal, November 2014

  • Greenwald, M.; Bader, A.; Baek, S.
  • Physics of Plasmas, Vol. 21, Issue 11
  • DOI: 10.1063/1.4901920

Verification of GENE and GYRO with L-mode and I-mode plasmas in Alcator C-Mod
journal, April 2018

  • Mikkelsen, D. R.; Howard, N. T.; White, A. E.
  • Physics of Plasmas, Vol. 25, Issue 4
  • DOI: 10.1063/1.5018741

Scale Separation between Electron and Ion Thermal Transport
journal, May 2008


The effect of ion-scale dynamics on electron-temperature-gradient turbulence
journal, July 2007


Methodology for turbulence code validation: Quantification of simulation-experiment agreement and application to the TORPEX experiment
journal, March 2011

  • Ricci, Paolo; Theiler, C.; Fasoli, A.
  • Physics of Plasmas, Vol. 18, Issue 3
  • DOI: 10.1063/1.3559436

Validation of the gyrokinetic model in ITG and TEM dominated L-mode plasmas
journal, November 2013


Synergistic cross-scale coupling of turbulence in a tokamak plasma
journal, November 2014

  • Howard, N. T.; Holland, C.; White, A. E.
  • Physics of Plasmas, Vol. 21, Issue 11
  • DOI: 10.1063/1.4902366

Cross-Scale Interactions between Electron and Ion Scale Turbulence in a Tokamak Plasma
journal, June 2015