Characterization of GEKKO⁄HIPER-Driven Shock Waves for Equation-of-State Experiments in Ultra-High-Pressure Regime

Abstract

The GEKKO⁄HIPER-laser driven shock experiments were characterized in detail for studies on equation-of-state (EOS) in ultra-high pressure regime. High-quality shock waves were produced with optically smoothed laser beams. Key issues on EOS measurement with shock waves, the spatial uniformity and the temporal steadiness of shock, and the preheating problem were investigated by measurements of the self-emission and reflectivity from target rear surface. Our experiments and analysis based on impedance matching method were validated by use of double-step targets consisting of two Hugoniot standard metals. Extreme shock waves previously only achieved in nuclear explosion experiments were generated using the laser direct-drive experimental scheme.