The Three-dimensional Torsional Magnetic Reconnection Experiment

Three-dimensional torsional magnetic reconnection (TMR) is a widely unexplored area of fundamental plasma science. The uniqueness of TMR stems from featuring rotational perturbations to a fan-spine topology of 3D magnetic null points. TMR in the solar atmosphere is associated with high-energy directed solar coronal jets and contributions to the solar wind budget. This DOE-enabled collaboration with the University of Alabama at Huntsville (UAH) is focused on operating the first TMR experiment to demonstrate laboratory-scale directed plasma jets with applications to spacecraft propulsion and fusion energy science. We have operated a coaxial plasma gun (CPG) within a strong 1 Tesla fan-spine topology to investigate the qualitative onset of TMR. This precision is enabled by solid-state pulsed power switching of discrete systems at 4+ kV and 8+ kA. This presentation describes the formation of the CPG plasma within the magnetic field and the evolution of downstream plasma dynamics resolved by an 8.7 us shutter speed global shutter camera system. The deployment of diagnostic systems is described, including triple probes, heterodyne interferometry, and optical emission spectroscopy (OES). Complementary theory & modeling efforts include 1D and 2D resistive magnetohydrodynamics (MHD) modeling, and smoothed particle hydrodynamics (SPFMax) methods to understand the onset of 3D TMR and enable the diagnosing of current sheet formation and magnetic field line annihilation within the reconnection region.