Study of magnetic reconnection in ion-scale magnetospheres on the Large Plasma Device*

Magnetic reconnection is a fundamental process occurring in magnetospheres and other space and astrophysical objects that can lead to topological reorganization of the magnetic fields as well as transfer of magnetic energy to the plasma. We report on the experimental study of magnetic reconnection in laser-driven ion-scale magnetospheres on the Large Plasma Device. In our experiment, we use a high-repetition rate (1 Hz), nanosecond laser to drive a fast moving plasma that expands into the field generated by a pulsed magnetic dipole embedded into a background plasma and magnetic field. The dipole and background fields are oriented to be anti-parallel, so that a magnetic null point naturally occurs. When the laser-plasma expands into the background plasma, it compresses the magnetic field and drives magnetic reconnection at this null point.

The magnetic and electric fields are measured with magnetic flux and emissive probes in a 3D volume around the reconnection point to characterize its effect on the global structure of the magnetosphere. By comparing our experimental results with Particle-in-Cell simulations, we gain insights on the kinetic-scale physics governing magnetic reconnection in ion-scale magnetospheres.