Simulation of Energy Coupling of Laser and Ablated Plasma at Target Surface

Under the irradiation of power laser, the material of solid target surface evaporated instantly and then the vapor plasma of target generated, coupling the energy of laser beam with plasma during the laser go through the plasma field to arrive at the target surface were the main physical process of laser interaction with plasma. A general Godunov finite difference schemes-WENO (Weighted Essentially Non-Oscillatory) schemes which have fifth-order accuracy is used to perform a numerical calculation for 2-dimensional axis symmetrical laser-supported plasma flow field under laser ablated solid target. The models for the calculation of ionization degree of plasma and the interaction between laser beam and plasma and the simplified EOS (equation of state) of plasma are considered in the simulation, the energy of laser absorbed in the plasma and the shielding effect of plasma were analyzed. Simulation results showed that the main portion of laser energy was used to drive the plasma flow, the shielding effect played an important role in the coupling of laser and plasma, the variation of the duration time of laser pulse could adjust the shielding effect which influenced the coupling of laser energy and plasma.