Experimental and Theoretical Study of the Propagation of Proton Beams under the Action of Laser Radiation with Allowance for Magnetic Reconnection

The propagation of proton beams at the Neodim laser facility has been simulated experimentally and theoretically. The spatial structure, divergence, and energy of proton beams appearing on the back surface of a thin copper target irradiated by laser pulses with a peak intensity of about 5 × 10 18 W/cm 2 have been studied. An extremely small divergence of 0.05° has been detected for a 2.9-MeV proton beam. The Sweet–Parker model of magnetic reconnection has been used to theoretically explain the experimental data obtained.