2019/12/23 by Jackson Matteucci, Matteucci, Jackson, W. Fox +15
Engineering · Physics and Astronomy · #Atomic and Molecular Physics #FOS: Physical sciences #Laser-Plasma Interactions and Diagnostics #Laser-induced spectroscopy and plasma #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.1912.11120
openalex publication_date 2019/12/23 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
First-principles kinetic simulations are used to investigate magnetic field\ngeneration processes in expanding ablated plasmas relevant to laser-driven\nfoils and hohlraums. In addition to Biermann-battery-generated magnetic fields,\nstrong filamentary magnetic filaments are found to grow in the corona of single\nexpanding plasma plumes; such filaments are observed to dominate Biermann\nfields at sufficiently large focal radius, reaching saturation values of \∼\n100 T at National Ignition Facility-like drive conditions. The filamentary\nfields result from the ion Weibel instability driven by relative\ncounterstreaming between the ablated ions and a sparse background population,\nwhich could be the result of a gas prefill in a hohlraum or laser pre-pulse.\nThe ion-Weibel instability is robust with the inclusion of collisions and grows\non a timescale of 100 ps, with a wavelength on the scale of 100-250 \μm,\nover a wide range of background population densities; the instability also\ngives rise to coherent density oscillations. These results are of particular\ninterest to inertial confinement fusion experiments, where such field and\ndensity perturbations can modify heat-transport as well as laser propagation\nand absorption.\n