The 8th International Conference on Matter and Radiation at Extremes (ICMRE2025)

86 / 2025-03-13 12:43:07

Simulation of Laser Plasma Energy Coupling Based on a Particle-Mesh Code

激光等离子体不稳定性,碰撞吸收,惯性约束聚变,能量耦合,粒子网格方法

Improving the quality of laser-target energy coupling is a critical issue in inertial confinement fusion (ICF), where the coupling and competition between collisional absorption and laser plasma instabilities (LPIs) directly determine the energy deposition efficiency. A one-dimensional kinetic-hydrodynamic code PM1D is developed based on the particle-mesh method, enabling simultaneously accurate simulations of collisional effects and LPIs at large temporal and spatial scales. Modified collisional damping operators are introduced into the electromagnetic wave propagation equation and motion equations of electrons and ions, complemented by additional temperature equations to describe energy deposition processes, involving the conversion of directional kinetic energy into thermal energy. Comparing with theoretical predictions, the upgraded PM1D code demonstrates capabilities to accurately simulate collisional absorption under varying plasma densities and laser intensities, capture collisional effects on suppressing the linear growth rate of stimulated Raman scattering (SRS), and maintain numerical stability for durations exceeding 220ps. Furthermore, PM1D is able to self-consistently deal with the temperature evolution, simulating both the collisional effects weakening and obvious red-shift in the backscattered SRS spectrum induced by collisional heating.