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Comparisons of Kinetic Effects on Heat Transport to Classical Fluid Models in Magnetized Gaspipes on NIF

ORAL

Abstract

We present simulations of heat flow relevant to magnetized gaspipe experiments on NIF to investigate kinetic effects on transport phenomena. These D2 and CH filled gas pipe targets are used to study the laser preheat stage of a MagLIF scheme where an axial magnetic field is applied to the target[1]. Initial simulations of these gas pipes were done with MHD code Gorgon[2] with a collision-dominated fluid model. However, the Knudsen number, the ratio between the electron mean free path and temperature scale lengths, was found to exceed 0.01 in substantial regions of space indicating the regime where non-local effects are important for heat flow. Non-local effects are a primary candidate for why the observed heat

flux is greatly over or under predicted by classical transport models such as Spitzer-Harm or Braginskii. Motivated for further kinetic study, we utilize Gorgon to initialize our plasma conditions and couple it with the Vlasov Fokker-Planck K2 code[3] until a steady state is reached to examine the impact of kinetic effects on heat transport. This talk will discuss the comparisons and calculations between the extracted kinetic heat flux from K2 and classical transport models.

Publication: [1] B. Pollock, et. al. submitted to Phys. Plasmas<br>[2] J.P. Chittenden et. al. Plasma Phys. control Fusion 46 B457 (2004).<br>[3] M. Sherlock, J. P. Brodrick, and C. P. Ridgers, Phys. Plasmas 24, 082706 (2017).[1] B. Pollock, et. al. submitted to Phys. Plasmas

Presenters

  • Ryan Y Lau

    University of Colorado, Boulder

Authors

  • Ryan Y Lau

    University of Colorado, Boulder

  • David J Strozzi

    Lawrence Livermore Natl Lab, LLNL

  • Mark Sherlock

    Lawrence Livermore Natl Lab

  • William A Farmer

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory

  • Yuan Shi

    LLNL, Lawrence Livermore Natl Lab