Princeton Center for Heliophysics Seminar

In this talk, I'll discuss our recent work on the Terrestrial Reconnection Experiment (TREX) where magnetic reconnection is explored with asymmetric inflow conditions and in a configuration where the absolute rate of reconnection is set by an external drive. We find that magnetic pileup enhances the upstream magnetic field of the high-density inflow, leading to an increased upstream Alfvén speed, helping to lower the normalized reconnection rate to values expected from theoretical consideration. In addition, a shock interface between the far upstream supersonic plasma inflow and the region of magnetic flux pileup is observed, important to the overall force balance of the system, thereby demonstrating the role of shock formation for configurations including a supersonically driven inflow. Given the small system size relative to the ions, the observed normalized reconnection rate is consistent with a range of previous numerical results indicating a possible transition to "electron only" reconnection. These experimental results have also been corroborated through the use of PIC simulations utilizing the specialized TREX geometry and driving mechanism, showing similar scaling of the reconnection rate with system size. Finally, I'll touch on recent ongoing work to upgrade the reconnection drive system in an effort to reach more kinetic regimes of reconnection where effects such as electron pressure anisotropy are expected.