Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications
Abstract
Three models for nonlocal electron thermal transport are here compared against VlasovFokkerPlanck (VFP) codes to assess their accuracy in situations relevant to both inertial fusion hohlraums and tokamak scrapeoff layers. The models tested are (i) a momentbased approach using an eigenvector integral closure (EIC) originally developed by Ji, Held, and Sovinec [Phys. Plasmas 16, 022312 (2009)]; (ii) the nonFourier Landaufluid (NFLF) model of Dimits, Joseph, and Umansky [Phys. Plasmas 21, 055907 (2014)]; and (iii) Schurtz, Nicolaï, and Busquet’s [Phys. Plasmas 7, 4238 (2000)] multigroup diffusion model (SNB). We find that while the EIC and NFLF models accurately predict the damping rate of a smallamplitude temperature perturbation (within 10% at moderate collisionalities), they overestimate the peak heat flow by as much as 35% and do not predict preheat in the more relevant case where there is a large temperature difference. The SNB model, however, agrees better with VFP results for the latter problem if care is taken with the definition of the mean free path. Additionally, we present for the first time a comparison of the SNB model against a VFP code for a hohlraumrelevant problem with inhomogeneous ionisation and show that the model overestimates the heat flow in the heliummore »
 Authors:
 Univ. of York (United Kingdom). Department of Physics, York Plasma Institute
 Imperial College, London (United Kingdom). Plasma Physics Group, Blackett Laboratory
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 MaxPlanckInstitute for Plasma Physics (Germany)
 Chalmers University of Technology (Sweden). Department of Physics
 Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL)
 Publication Date:
 Research Org.:
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1393324
 Alternate Identifier(s):
 OSTI ID: 1378821
 Report Number(s):
 LLNLJRNL727659
Journal ID: ISSN 1070664X
 Grant/Contract Number:
 AC5207NA27344
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Physics of Plasmas
 Additional Journal Information:
 Journal Volume: 24; Journal Issue: 9; Journal ID: ISSN 1070664X
 Publisher:
 American Institute of Physics (AIP)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Citation Formats
Brodrick, Jonathan P., Kingham, R. J., Marinak, M. M., Patel, M. V., Chankin, A. V., Omotani, J. T., Umansky, M. V., Del Sorbo, D., Dudson, B., Parker, J. T., Kerbel, G. D., Sherlock, M., and Ridgers, C. P. Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications. United States: N. p., 2017.
Web. doi:10.1063/1.5001079.
Brodrick, Jonathan P., Kingham, R. J., Marinak, M. M., Patel, M. V., Chankin, A. V., Omotani, J. T., Umansky, M. V., Del Sorbo, D., Dudson, B., Parker, J. T., Kerbel, G. D., Sherlock, M., & Ridgers, C. P. Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications. United States. doi:10.1063/1.5001079.
Brodrick, Jonathan P., Kingham, R. J., Marinak, M. M., Patel, M. V., Chankin, A. V., Omotani, J. T., Umansky, M. V., Del Sorbo, D., Dudson, B., Parker, J. T., Kerbel, G. D., Sherlock, M., and Ridgers, C. P. 2017.
"Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications". United States.
doi:10.1063/1.5001079. https://www.osti.gov/servlets/purl/1393324.
@article{osti_1393324,
title = {Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications},
author = {Brodrick, Jonathan P. and Kingham, R. J. and Marinak, M. M. and Patel, M. V. and Chankin, A. V. and Omotani, J. T. and Umansky, M. V. and Del Sorbo, D. and Dudson, B. and Parker, J. T. and Kerbel, G. D. and Sherlock, M. and Ridgers, C. P.},
abstractNote = {Three models for nonlocal electron thermal transport are here compared against VlasovFokkerPlanck (VFP) codes to assess their accuracy in situations relevant to both inertial fusion hohlraums and tokamak scrapeoff layers. The models tested are (i) a momentbased approach using an eigenvector integral closure (EIC) originally developed by Ji, Held, and Sovinec [Phys. Plasmas 16, 022312 (2009)]; (ii) the nonFourier Landaufluid (NFLF) model of Dimits, Joseph, and Umansky [Phys. Plasmas 21, 055907 (2014)]; and (iii) Schurtz, Nicolaï, and Busquet’s [Phys. Plasmas 7, 4238 (2000)] multigroup diffusion model (SNB). We find that while the EIC and NFLF models accurately predict the damping rate of a smallamplitude temperature perturbation (within 10% at moderate collisionalities), they overestimate the peak heat flow by as much as 35% and do not predict preheat in the more relevant case where there is a large temperature difference. The SNB model, however, agrees better with VFP results for the latter problem if care is taken with the definition of the mean free path. Additionally, we present for the first time a comparison of the SNB model against a VFP code for a hohlraumrelevant problem with inhomogeneous ionisation and show that the model overestimates the heat flow in the helium gasfill by a factor of ~2 despite predicting the peak heat flux to within 16%.},
doi = {10.1063/1.5001079},
journal = {Physics of Plasmas},
number = 9,
volume = 24,
place = {United States},
year = 2017,
month = 9
}

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