Shock processing of materials with laser initiated spherically convergent detonations

We describe a new technique for dynamically compressing materials using small scale spherically converging shock waves driven by laser initiated high explosives. This technique uses spherical targets consisting of an outer explosive shell of 1--2 cm diam, and an inner sample core 0.48--0.96 cm diam. The shock waves result from a detonation wave generated near the outer surface of the explosive by a high-power laser. Spherical convergence and shock impedance matching produce ingoing shock waves in the core which have pressure amplitudes much greater than the detonation pressure of the explosive. Shock pressures in the sample core are typically in the range 10--200 GPa depending on the radius, density, and composition of both the explosive layer and the inner core. We discuss the hydrodynamic modeling of our implosion process, the conditions required for laser initiated detonation, and the results of boron nitride and carbon recovery experiments