Formations of multiple magnetic reconnection configurations in SPERF-TREX

Magnetic reconnection in space and astrophysical plasmas is generally intrinsically three-dimensional (3D), involving complicated configurations that pose significant challenges for in-situ observations. Thus, ground-based experiments can provide a potential means to diagnose both global and local processes simulating space and astrophysical events. In this work, we demonstrate designated magnetic reconnection configurations in a recently established laboratory simulation facility for space and astrophysical plasmas research, Space Plasma Environment Research Facility, Tail Research EXperiment (SPERF-TREX). In a numerical simulation analysis, we identify four representative configurations: (A) a single-X-line geometry of either a southward-IMF-like or a magnetotail-neutral-line-like configuration, (B) a northward-IMF-like double-cusp geometry with a symmetric pair of magnetic nulls, (C) a multi-site reconnection geometry featuring a coupled midplane X-line and a null pair, and (D) an evolutionary sequence from double X-lines to a mixed O-X-line configuration, with the creation of an A-B null pair and secondary nulls in the O-X transition, relevant to complex magnetic topology of solar corona events. Such magnetic topology similarity can link adjustable laboratory parameters to key space and astrophysical observables, providing testable predictions for diagnostics and a controlled framework for 3D multi-site reconnection relevant to various events observed in magnetospheric and astrophysical environments.