3D Magnetic Null Points Formation and Motion During Reconnection in the Laboratory*

In configurations observed in natural systems, 3D magnetic null points often appear during magnetic reconnection [1]. In the Terrestrial Reconnection Experiment (TREX) implemented at the Wisconsin Plasma Physics Laboratory (WiPPL), magnetic reconnection is studied under controlled conditions in the collisionless regime. The applied configuration includes a cylindrically symmetric reconnection layer imploding onto the central axis of the experiment [2]. The reconnection process ends as the reconnection layer reaches the center axis characterized by the formation of a double null-point configuration. This poster will discuss how the two null points form, the rapid separation along the experimental z-axis, and the energy conversion due to field line shortening. High fidelity B-dot probes are used for collecting magnetic field data that resolve the dynamics at length scales much smaller than the ion skin-depth. The experiment reveals the importance of two-fluid Hall effects yielding both quadrupolar and octopolar structures in the out-of-plane magnetic field.