Kinetic simulations of plasma mirror instabilities

Chun-Kai Chang^1*, Lin-Ni Hau^1,2

¹Graduate Institute of Space science and Engineering, National Central University, Taoyuan City, Taiwan
²Department of Physics, National Central University, Taoyuan City, Taiwan

* Presenter:Chun-Kai Chang, email:chunkai13@g.ncu.edu.tw

In a magnetized plasma, a low-frequency mirror instability may occur as the temperature anisotropy reaches a critical threshold value. The mirror instability was first discovered in the fluid model but its instability conditions were found to be inconsistent with the kinetic theory. In particular, the mirror instability cannot occur in a plasma with adiabatic energy conditions. The major characteristics of mirror instabilities is the formation of magnetic field holes or peaks associated with the density peaks or dips. The mirror waves have been widely observed in the solar system. In this study we examine the time evolution of mirror instability by adopting the kinetic particle simulations. In the model the ions are treated as kinetic particles and the electrons are regarded as a fluid due to the consideration that the mirror structures are in general larger than the ion inertial scales. It is shown that the phase relations among the various physical quantities and the widths of the mirror waves are consistent with the observations.

Keywords: mirror instability, Kinetic simulation, temperature anisotropy, mirror waves