2019/10/28 by Gregory Ngirmang, John T. Morrison, Ngirmang, Gregory K. +13
Engineering · Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Laser-Plasma Interactions and Diagnostics #Laser-induced spectroscopy and plasma #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.1910.12940
openalex publication_date 2019/10/28 · openalex created_date 2022/07/28 · openalex updated_date 2026/07/28
When a relativistic intensity laser interacts with the surface of a solid\ndensity target, suprathermal electron currents are subject to Weibel\ninstability filamentation when propagating through the thermal population of\nthe bulk target. We present time resolved shadowgraphy of radial ionization\nfront expansion and Weibel instability filamentation within a thin, sub-micron,\nsheet initiated by irradiation with a short pulse, high intensity laser. High\ntemporal (100 fs) and spatial (1 \μm) resolution shadowgraphy of the\ninteraction reveals a relativistic expansion of the ionization front within a\n120 \μm diameter region surrounding the laser-target interaction,\ncorroborated by simulations to expand at 0.77c, where c is the speed of\nlight. Filamentation within the patch persists for several picoseconds and\nseeds the eventual recombination and heating dynamics on the nanosecond\ntimescale. Particle-in-cell simulations were conducted to elucidate the\nelectron dynamics leading to the radial expansion of the critical surface.\nComputational results report the ionization expansion is due to field\nionization of the expanding hot electron population. Filamentation within the\nexpansion is due to the Weibel instability which is supported by the magnetic\nfields present.\n