Kinetic simulation of magnetic field generation via the Biermann Battery effect for laser-driven HED experimental conditions

The Biermann Battery effect is one of the few mechanisms known to spontaneously generate magnetic fields in plasmas. Recently, this effect, which operates through a non-collinearity of the gradients in electron density and temperature, has been used to generate strong magnetic fields (10-100 T) in High Energy Density (HED) plasma experiments using high-intensity lasers. Recent kinetic simulations have investigated this effect under model profiles of density and temperature; however, connection of these results to physical experiments, which evolve dynamically, has limited applicability. Using fully kinetic, particle-in-cell simulations, we are able to model the laser ablation process from a flat foil, including the self-consistent generation of the magnetic field via the Biermann effect, allowing for direct connection to experiments. We characterize Biermann generation (both maximum field and total flux generated with respect to time) as a function of the laser deposition profile, laser spot radius, the system’s collisionality, the ion species, and the density of the background population. This work allows for a direct characterization of the expected magnetic field generation solely based on the HED experimental parameters.