Shock-timing experiments using double-pulse laser irradiation

The timing of multiple shock waves is crucial to the performance of inertial confinement fusion ignition targets. Presented are measurements of velocities and optical self-emission from shock waves in polystyrene targets driven by two 90-ps pulses separated by 1.5-2 ns. These pulses drive two shock waves that coalesce in the target, and the resultant velocity histories, coalescence times, and transit times are unambiguously observed in both velocity interferometry and self-emission data. These results are in good agreement with one-dimensional hydrodynamics code predictions. (c) 2006 American Institute of Physics.