Three‐dimensional structure of magnetic reconnection in a laboratory plasma

Abstract

The local three‐dimensional structure of magnetic reconnection has been measured for the first time in a magnetohydrodynamic (MHD) laboratory plasma at the Swarthmore Spheromak Experiment. An array of 600 magnetic probes which resolve ion inertial length and MHD time scale dynamics on a single shot basis measured the magnetic structure of partial spheromak merging events. Counter‐helicity spheromaks merge rapidly, and reconnection activity clearly self‐generates a local component of B which breaks the standard 2D symmetry at the ion inertial scale. Consistent with prior results, no reconnection is observed for co‐helicity merging.