Electromagnetic instability of thin reconnection layers: Comparison of three-dimensional simulations with MRX observations

The influence of current-aligned instabilities on magnetic reconnection in weakly collisional regimes is investigated using experimental observations from Magnetic Reconnection Experiment (MRX) [M. Yamada et al., Phys. Plasmas 4, 1936 (1997)] and large-scale fully kinetic simulations. In the simulations as well as in the experiment, the dominant instability is localized near the center of the reconnection layer, produces large perturbations of the magnetic field, and is characterized by the wavenumber that is a geometric mean between electron and ion gyroradii k∼(ρeρi)−1/2. However, both the simulations and the experimental observations suggest the instability is not the dominant reconnection mechanism under parameters typical of MRX.