Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications
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Published version
OA Location
Author(s)
Type
Journal Article
Abstract
Three models for nonlocal electron thermal transport are here compared against Vlasov-Fokker-Planck (VFP) codes to assess their accuracy in situations relevant to both inertial fusion hohlraums and tokamak scrape-off layers. The models tested are (i) a moment-based approach using an eigenvector integral closure (EIC) originally developed by Ji, Held, and Sovinec [Phys. Plasmas 16, 022312 (2009)]; (ii) the non-Fourier Landau-fluid (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 small-amplitude 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 hohlraum-relevant problem with inhomogeneous ionisation and show that the model overestimates the heat flow in the helium gas-fill by a factor of ∼2 despite predicting the peak heat flux to within 16%.
Date Issued
2017-09-06
Date Acceptance
2017-08-06
Citation
PHYSICS OF PLASMAS, 2017, 24 (9)
ISSN
1070-664X
Publisher
AIP Publishing
Journal / Book Title
PHYSICS OF PLASMAS
Volume
24
Issue
9
Copyright Statement
© 2017 Author(s). All article content, except where
otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000412107400035&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
EP/C531566/1
EP/M01102X/1
Subjects
Science & Technology
Physical Sciences
Physics, Fluids & Plasmas
Physics
SCRAPE-OFF LAYER
PARALLEL TEMPERATURE-GRADIENTS
FOKKER-PLANCK EQUATION
ION-ACOUSTIC-WAVES
HEAT-TRANSPORT
INVERSE BREMSSTRAHLUNG
NUMERICAL-SOLUTION
PLASMA TRANSPORT
SELF-CONSISTENT
LASER PLASMAS
0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics
0201 Astronomical And Space Sciences
0203 Classical Physics
Fluids & Plasmas
Publication Status
Published
Article Number
ARTN 092309