Observations of Plasmoids in Pulse-Power Driven Magnetic Reconnection Experiments

We present a detailed study of magnetic reconnection in a quasi-two-dimensional pulsed-power driven laboratory experiment. Oppositely directed magnetic fields, advected by supersonic and sub-Alfv\'enic carbon plasma flows, are brought together and mutually annihilate inside a thin current layer. Temporally and spatially resolved non-perturbative diagnostics allow us to determine the structure and dynamics of this layer, the nature of the inflows and outflows and details of the energy conversion by the reconnection process. We find evidence for anomalous resistivity inside the layer, and for the presence of two fluid effects in the form of density depletion regions. We observe plasmoids, consistent with the predictions of semi-collisional plasmoid instability theory, which may cause enhanced viscous heating of the ions.