2-D PIC Simulations of Magnetized Current Sheet Formation in Laser-Solid Plasmas

In high power laser-solid interactions, strong non-collinear electron density and temperature gradients create megagauss-scale azimuthal magnetic fields via the Biermann-battery effect. These fields can magnetize the ablated plasma (ω_ce𝜏_ei > 1), altering processes such as the electron heat transport. When two such plumes are placed next to each other, their opposing magnetic fields collide and can undergo magnetic reconnection-- the process which converts stored magnetic energy into plasma thermal and kinetic energy in a current sheet. Since magnetization can influence global plasma dynamics, it is particularly relevant to study magnetization within the reconnection region as well.

Here, 2-D simulations of the generation and collision of two laser-produced plasma plumes are performed using the fully kinetic particle-in-cell code PSC with a laser-ray tracing module. We observe the formation of a magnetized current sheet between these plumes under a range of high-energy-density and inertial confinement fusion relevant conditions. We vary the target material, the distance between lasers, and the laser intensity, beam radius, and wavelength, finding that this sheet forms and magnetizes as the distance between laser spots and laser intensity is increased. Finally, the effect of the magnetized heat transport on current sheet temperature and structure is studied.