Expansion of laser-produced plasma

Irradiation of a solid target with a high power laser beam pressures in the matter up to tens and hundreds Mbar by the ablating plasma. The measurement of induced shock pressures is very useful and a sensitive parameter for optimizing compression in the inertial confinement fusion research for various experimental conditions (laser wavelength, pulse duration, etc.). On the other hand, such ultrahigh-pressure shock waves, which are not achievable in conventional laboratory experiments (flyer impact, explosive loads), have led to a strong interest in obtaining data measurements. Numerical simulation of laser-target interaction was conducted by many authors. One- and two-dimensional codes were used for these investigations. Because of the physical difficulty described phenomena it was used the different physical models with much simplicity proposition. Full description of laser-matter interaction must include such problems as: laser energy absorption, transport of the irradiated energy and subsequent ablation of the target; interaction of the ablated plasma with the ambient gas and formation of a shock and rarefaction waves; dependence of the energy absorption on the angle incidence and polarization of the laser pulse; instability fimbriation and evolution; fluency of the electromagnetic fields on the ablated plasma motion, both the early equilibrium and later nonequilibrium chemistry processes; electron-lattice relaxation phenomenon; irradiation of the plasma in the ambient gas, and so on. Metal (aluminum) targets with thickness 250 nm were used. Parameters of the laser pulse varies in range: intensity I equals 1013 - 1015 W/cm2, duration varies in the range from 30 fs to 200 fs, wavelength lambda equals 0.35 mkm. The investigation has been performed by the 2-D Godunov's numerical scheme.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.