Regulation of the Normalized Rate of Driven Magnetic Reconnection through Shocked Flux Pileup

Magnetic reconnection is explored on the Terrestrial Reconnection Experiment\footnote{Olson, J., \textit{et al.}, Phys. Rev. Letters, \textbf{116}, 255001 (2016).} at the Wisconsin Plasma Physics Laboratory\footnote{Forest, C.B., \textit{et al.}, J. Plasma Phys., \textbf{81}, 1 (2015)} where the absolute rate of reconnection is set by an external drive. A shock interface between the supersonically driven plasma inflow and a region of magnetic flux pileup permits the normalized reconnection rate to self regulate to a fixed value. The observations demonstrate the role of shock formation in driven reconnection and confirm previous theoretical results on the normalized rate of reconnection.