Graduate student Thomas Varnish’s recent paper in Physics of Plasmas has been selected as a Featured Article. Thomas studied some mysterious density structures which appeared in experiments on the MAIZE facility at the University of Michigan. We’ve done experiments with anti-parallel reconnection before, but in nature the field lines usually meet at some angle, and resulting in a reconnecting component and an additional “guide field” component.

To produce this guide field component in the laboratory, Thomas tilted the two exploding wire arrays in opposite directions. Tilting the wire arrays embedded a guide field, but created a three dimensional current sheet which was tricky to diagnose with line-integrated diagnostics. After carefully analysing the data and comparing it to analytical models and 3D simulations, we were able to link the distinctive quadrupolar density structures we observed to two-fluid effects in the presence of a guide field!

We’re grateful to our collaborators at the University of Michigan, led by Ryan McBride, for letting us use MAIZE, and to the NSF and NNSA for supporting this research. You can read the full paper here, and a popular science overview of it here.