Magnetic reconnection is a fundamental plasma process whereby two merging flows with oppositely oriented magnetic fields drive the reconfiguration of the field topology inside a current sheet, which rapidly converts magnetic into kinetic energy. Magnetic reconnection commonly occurs in both laboratory experiments, in heliophysics, and astrophysics and power some of the most explosive events in the universe.

In this talk, I will present results from magnetic reconnection experiments conducted at the National Ignition Facility (NIF). Two highly extended plasma plumes are produced by tiling a total of 40 laser beams which become self-magnetized through the Biermann battery effect [1]. As they collide, they form a reconnecting current sheet in the interaction region with a high aspect ratio. The plasma is simultaneously probed using proton radiography [2] and X-ray self-emission which characterize the magnetic field and electron temperature [3].

We have found that the current sheet narrows down to scales comparable to the electron gyroradius, from which reconnected electric fields and current densities can be inferred. I will discuss the insufficiency of Spitzer resistivity at accounting to the observed reconnection rate, and also, that the observer electron heating cannot be explained by magnetic reconnection in the high-density regime. However, accounting for kinetic effects such as momentum flux [4] and collisional drag can explain the experimental observations.

[1] W. Fox et al. submitted to Physical Review Letters.

[2] W. Fox et al. accepted in Physical Review E.

[3] V. Valenzuela-Villaseca et al. submitted to Physics of Plasmas.

[4] H. Hesse et al., Physics of Plasmas, 1999.