Particle Acceleration due to Magnetically Driven Reconnection at low-β using Laser-Powered Capacitive Coils*

Magnetic Reconnection is the ubiquitous astrophysical process in which a plasma rapidly converts magnetic field energy into a combination of flow energy, thermal energy and non-thermal energetic particles. Various acceleration mechanisms (including Fermi acceleration, betatron acceleration, reconnection electric field acceleration and electric field acceleration across magnetic fields) have been theoretically proposed and numerically studied in collisionless low-β environments. Only recently [1] has this environment been experimentally studied using long-pulse lasers to drive parallel currents in a quasi-axisymmetric capacitive coil target. This process achieves MegaGauss-level magnetic reconnection and indicates that the primary acceleration mechanism is the out-of-plane electric field in this setup. We extend this analysis and present new results on a short-pulse laser platform that allows us to drive magnetic reconnection at higher field strength. Preliminary results indicate that the peak of accelerated electron energy increases with the magnetic field. We then present future laser-target reconnection concepts that will allow us to both further verify these results and directly study alternative particle acceleration mechanisms.

[1]: A. Chien, L. Gao, S. Zhang, H. Ji, E. G. Blackman, W. Daughton, A. Stanier, A. Le, F. Guo, R. Follett, H. Chen, G. Fiksel, G. Bleotu, R. C. Cauble, S. N. Chen, A. Fazzini, K. Flippo, O. French, D. H. Froula, J. Fuchs, S. Fujioka, K. Hill, S. Klein, C. Kuranz, P. Nilson, A. Rasmus, and R. Takizawa, “Non-thermal electron acceleration from magnetically driven reconnection in a laboratory plasma,” Nature Physics 19, 254–262 (2023)