Effects of anomalous high penetration rate of high-power KrF laser radiation throughout the solid matter and shock-induced graphite-diamond phase transformation

摘要

Abstract: This paper describes a performance of 100 J-class KrF laser system `GARPUN' intended for target irradiation experiments by 100 ns pulses. A controllable space-time distribution in a focal spot reaching 5*10$+12$/ W/cm$+2$/ produced megabar ablation pressure, which irradiated conical shock wave in solids. It propagated in a quasi-steady manner together with an ablation front that resulted in anomalous high penetration rate of laser radiation throughout the matter. Long-time sample loading together with strong tangential shear flow of compressed layers produced favorable conditions for pressure-induced transformation of the pyrolytic graphite into a diamond-like phase by martensitic mechanism.!30