Description
Understanding the evolution of magnetic fields in laser-produced plasmas is vital for advancing Inertial Confinement Fusion (ICF) research. This study focuses on the influence of self-generated and externally applied magnetic fields on the interaction of high-power laser beams with foam targets, leading to foam homogenization, a critical step in ensuring plasma uniformity for subsequent interactions. Using the extended magnetohydrodynamic (ExMHD) model, we characterize magnetic-field transport and generation in collisional plasmas by performing simulations with the FLASH code.
The simulations are modeled after the experimental configuration at the Prague Asterix Laser System (PALS), which utilizes a dual-beam setup: an auxiliary 1315 nm beam for foam heating and homogenization, followed by a main 438 nm beam to investigate parametric instabilities in long-scale-length plasma. The primary objective of this work is to determine the plasma conditions and the rate of foam homogenization prior to or during the interaction with the main beam.
The Nernst effect plays a dominant role, driving strong magnetic-field advection along temperature gradients. This often leads to magnetic-field cavitation at the center of the laser beam. Consequently, this study aims to understand this effect for different experimental conditions and quantify the magnetic field that persists within the interaction region. The simulation results serve as a foundational predictive tool for the upcoming experimental campaign at PALS later this year.