Reconnection Drive Cylinder for the Terrestrial Reconnection Experiment*

The Terrestrial Reconnection EXperiment (TREX) at Wisconsin Plasma Physics Laboratory (WiPPL) [1] aims to explore the kinetic regime by driving an induced electric field through a cylindrical coil geometry. The enhanced drive will reduce the effective collisionality of the experiment, such that electron pressure anisotropy can develop unimpeded by Coulomb collisions providing a more accurate model of Earth’s magnetospheric plasma dynamics. The drive cylinder is composed of aluminum and Teflon, has a radius of 60cm, and is surrounded by 13 copper coils.  Compared to  TREX’s previous four drive coil configuration [2], we estimate that the drive cylinder reconnection current layer will be 70% longer, increase the absolute reconnection rate tenfold (up to E_rec ? 1kV/m), and reduce the collision frequency by a factor of four. These effects will allow us to reliably access the regime of kinetic reconnection where electron pressure anisotropy is known to strongly impact the reconnection dynamics.

[1] C. B. Forest et al., “The Wisconsin Plasma Astrophysics Laboratory,” Journal of Plasma Physics, vol. 81, Oct 2015.

[2] J. Olson et al., “Experimental demonstration of the collisionless plasmoid instability below the ion kinetic scale during magnetic reconnection,” Phys. Rev. Lett., vol. 116, Jun 2016.