A Laboratory Experiment of Magnetic Reconnection: Outflows, Heating and Waves in Chromospheric Jets

TL;DR

This laboratory experiment simulates chromospheric magnetic reconnection, revealing plasma outflows, heating, and wave phenomena, thus providing insights into the physics of solar chromospheric jets.

Contribution

The study experimentally reproduces key features of chromospheric jets through component reconnection, bridging the gap between solar observations and laboratory plasma physics.

Findings

Bi-directional plasma outflows up to 5 km/s observed

Ion heating exceeding 30 eV in downstream regions

Magnetic fluctuations with periods of 5-10 microseconds

Abstract

Hinode observations have revealed intermittent recurrent plasma ejections/jets in the chromosphere. These are interpreted as a result of non-perfectly anti-parallel magnetic reconnection, i.e. component reconnection, between a twisted magnetic flux tube and the pre-existing coronal/chromospheric magnetic field, though the fundamental physics of component reconnection is unrevealed. In this paper, we experimentally reproduced the magnetic configuration and investigated the dynamics of plasma ejections, heating and wave generation triggered by component reconnection in the chromosphere. We set plasma parameters as in the chromosphere (density 10^14 cm^-3, temperature 5-10 eV, i.e. (5-10)x10^4 K, and reconnection magnetic field 200 G) using argon plasma. Our experiment shows bi-directional outflows with the speed of 5 km/s at maximum, ion heating in the downstream area over 30 eV and magnetic fluctuations mainly at 5-10 us period. We succeeded in qualitatively reproducing chromospheric jets, but quantitatively we still have some differences between observations and experiments such as jet velocity, total energy and wave frequency. Some of them can be explained by the scale gap between solar and laboratory plasma, while the others probably by the difference of microscopy and macroscopy, collisionality and the degree of ionization, which have not been achieved in our experiment.