Why does steady-state magnetic reconnection have a maximum local rate of order 0.1?
Abstract
Simulations suggest collisionless steady-state magnetic reconnection of Harris-type current sheets proceeds with a rate of order 0.1, independent of dissipation mechanism. We argue this long-standing puzzle is a result of constraints at the magnetohydrodynamic (MHD) scale. We perform a scaling analysis of the reconnection rate as a function of the opening angle made by the upstream magnetic fields, finding a maximum reconnection rate close to 0.2. The predictions compare favorably to particle-in-cell simulations of relativistic electron-positron and non-relativistic electron-proton reconnection. The fact that simulated reconnection rates are close to the predicted maximum suggests reconnection proceeds near the most efficient state allowed at the MHD-scale. The rate near the maximum is relatively insensitive to the opening angle, potentially explaining why reconnection has a similar fast rate in differing models.
Keywords
Cite
@article{arxiv.1611.07859,
title = {Why does steady-state magnetic reconnection have a maximum local rate of order 0.1?},
author = {Yi-Hsin Liu and M. Hesse and F. Guo and W. Daughton and H. Li and P. A. Cassak and M. A. Shay},
journal= {arXiv preprint arXiv:1611.07859},
year = {2017}
}
Comments
Submitted to PRL for review on 08/17/2016. This article is a revision of arXiv:1605.05654. https://arxiv.org/abs/1605.05654