Energy Dissipation and Entropy in Collisionless Plasma
Abstract
It is well known that collisionless systems are dissipation free from the perspective of particle collision and thus conserve entropy. On the other hand, processes such as magnetic reconnection and turbulence appear to convert large-scale magnetic energy into heat. In this paper, we investigate the energization and heating of collisionless plasma. The dissipation process is discussed in terms of fluid entropy in both isotropic and gyrotropic forms. Evolution equations for the entropy are derived and they reveal mechanisms that lead to changes in fluid entropy. These equations are verified by a collisionless particle-in-cell simulation of multiple reconnecting current sheets. In addition to previous findings regarding the pressure tensor, we emphasize the role of heat flux in the dissipation process.
Cite
@article{arxiv.1911.08086,
title = {Energy Dissipation and Entropy in Collisionless Plasma},
author = {Senbei Du and Gary P. Zank and Fan Guo and Xiaocan Li},
journal= {arXiv preprint arXiv:1911.08086},
year = {2020}
}
Comments
19 pages, 4 figure