Space Plasma Climate Seminar

Heat-flow is of fundamental interest in plasmas with extreme temperature gradients. These plasmas can range from those found in laser-plasma experiments, to relativistic jets or tokamak divertors. Transport effects such as heat-flow are fundamentally driven by anisotropy within the distribution function in plasma systems. As anisotropy increases, the system is driven from local thermodynamic equilibrium (LTE). Fluid models, which often assume the anisotropy leads to only a small perturbation away from a Maxwellian distribution, can then fail to describe transport effects far from LTE accurately.

However, there is a coupling between anisotropic transport and magnetic field dynamics, with magnetic fields both modifying heat-flow and being advected with heat-flow via the Nernst effect. Here we will examine how magnetisation suppresses anisotropic transport and restores local thermodynamic equilibrium using kinetic Vlasov-Fokker-Planck simulations. This will be applied in the context of an experiment which provided the first direct measurement of the Nernst effect, where proton radiography and interferometry measurements were used to demonstrate a decoupling of the magnetic field advection from the bulk flow.