The first study of MHD tearing instability in generalized current sheets

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

¹Department 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

Pinch current sheet with antiparallel magnetic field is unstable to tearing instability, as first demonstrated by Furth et al. (1963). In this study we carry out the MHD simulations of tearing mode instability for the generalized Harris sheet equilibrium in nonthermal plasmas developed by Hau et al. (2023). The family of Harris equilibrium possesses various thicknesses of current sheets which permits the study of the relationship between the growth rates and the current sheet thickness for the first time. The eigenmode solutions and growth rates are obtained from the linear MHD simulations which shows an anticorrelation between the growth rates and current sheet thickness. The quantitative relationship is consistent with the theoretical prediction by Furth et al. (1963) which was not able to be confirmed by the prior studies due to the lack of generalized equilibrium solutions.

Keywords: MHD, space plasma, tearing mode instability, simulation , magnetic reconnection