Modeling of Laser-Generated Plasmas in a MG Magnetic Field

Experiments coupling a plasma generated by a laser pulse with fields generated by pulsed power have shown that localized plasma structures (disk or ring) are present long after the pulse has ended.[1] We model the effects of coupling a pulse of intensity ( ~10¹⁵ W/cm²) with a field in the azimuthal direction of ~4 MG generated by axial current in a rod in 2 spatial dimensions. We are able to see localized structures that exist in the presence of the azimuthal field that are not seen when no field (current) is present. These localized plasma structures resembling a disk continue to expand in both the axial and radial directions. The pulse initially expels the field from the plasma; however, later in time the field generated in the localized structure reaches the same order of magnitude as the initial field. We also investigate how the parameters β (beta) and χ (Hall) vary as the localized structure evolves in time.

[1] V. V. Ivanov et al., Plasma Phys. Control. Fusion 59, 085008 (2017).