Particle acceleration in magnetically-driven reconnection using laser-powered capacitor coils

Collisionless magnetic reconnection events in astrophysical plasmas have been observed to generate particles with energies far higher than the thermal background. For instance, nonthermal acceleration has been observed in the Earth's magnetosphere, where nonthermal electrons have energies of up to 10⁵ eV, compared to thermal electrons of a few eV; additionally, in solar flares, a large portion of released energy can be attributed to energetic electrons. The mechanisms behind nonthermal particle acceleration are not well understood: several theories have been hypothesized and tested in particle-in-cell simulations, but they have not been experimentally confirmed. Recently, laser-powered capacitor coils have emerged as a novel technique to generate strong external magnetic fields. These can be arranged to create a laboratory magnetic reconnection setup with low-β, collisionless reconnection, as well as measurement of the energetic electron energy spectrum. Preliminary results on the Omega EP laser facility at the Laboratory for Laser Energetics demonstrate evidence of particle acceleration due to magnetic reconnection; further experiments, combined with particle-in-cell simulations, will provide a better understanding of the specific acceleration mechanisms.