A laboratory experiment of magnetic reconnection: Outflows, heating, and waves in chromospheric jets

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 not revealed. 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 10¹⁴cm ^-3, temperature 5-10eV, i.e., (5-10) × 10⁴K, and reconnection magnetic field 200G) using argon plasma. Our experiment shows bi-directional outflows with the speed of 5kms^-1 at maximum, ion heating in the downstream area over 30eV, and magnetic fluctuations mainly at 5-10 μs period. We succeeded in qualitatively reproducing chromospheric jets, but quantitatively, we still have some differences between observations and experiments such as in 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 are probably due to the difference in microscopy and macroscopy, collisionality, and the degree of ionization, which have not been achieved in our experiment.