Suppression of Electron Thermal Conduction in High $β$ Plasma

G. T. Roberg-Clark, J. F. Drake, C. S. Reynolds, M. Swisdak

Published 2016-06-14Version 1

Electron heat conduction is explored with particle-in-cell simulations and analytic modeling in a high $\beta$ system relevant to galaxy clusters. Linear wave theory reveals that whistler waves are driven unstable by electron heat flux even when the heat flux is weak. The resonant interaction of electrons with these waves plays a critical role in controlling the impact of the waves on the heat flux. In a 1D model only electrons moving opposite in direction to the heat flux resonate with the waves and electron heat flux is only modestly reduced. In a 2D system transverse whistlers also resonate with electrons propagating in the direction of the heat flux and resonant overlap leads to strong suppression of electron heat flux. The results suggest that electron heat conduction might be strongly suppressed in galaxy clusters.