Kinetic simulations of the thermomagnetic instability in inertial fusion conditions

In laser-fusion conditions, the heat transport is well known to be reduced relative to theoretical predictions. Theoretical work over the last 4 decades has increased our understanding of the role of non-local effects in explaining the reduced heat flow, but a multiplier-free simulation capability remains elusive. A number of magnetic-field generating instabilities have long been suspected of playing a role in thermal transport in laboratory and astrophysical contexts, including the thermomagnetic instabilities [1]. We discuss the role of various transport instabilities in laser-plasmas and present the first 2D Vlaso-Fokker-Planck simulations of the thermomagnetic instability, highlighting the growth and saturation of the magnetic field, its effect on the heat flow in non-local conditions, and the formation of filamentary structures which disrupt symmetry.

[1] D.A.Tidman & R.A.Shanny, Field-generating thermal instability in laser-heated plasmas, Phys. Fluids 17, 1207 (1974).