PICOSECOND OPTICAL PROBING OF ULTRAFAST ENERGY-TRANSPORT IN SHORT-PULSE LASER SOLID TARGET INTERACTION EXPERIMENTS

This paper reports observations of rapid energy transport effects resu lting from high intensity laser heating of fused silica targets. Picos econd optical probing of these interactions provides information on th e kinematics of supersonic ionization fronts driven into the targets. Studies have been conducted as a function of laser intensity, waveleng th, and target angle. Additionally, targets with metallic surface laye rs have been investigated. Characterization of the laser absorption ha s enabled plasma and radiation hydrodynamics energy transport simulati ons to be implemented. Although consideration has been given to severa l energy transport mechanisms, including thermal and suprathermal elec tron transport, the kinematics are best explained with a radiation tra nsport model. This is confirmed by angled and high and medium Z coated target experiments. (C) 1998 American Institute of Physics. [S1070-66 4X(98)04010-5].