Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

Abstract This work presents first insights into the dynamics of free-surface release clouds from dynamically compressed polystyrene and pyrolytic graphite at pressures up to 200 GPa, where they transform diamond or lonsdaleite, respectively. These ejecta are released either vacuum various types catcher systems, monitored with high-speed recordings (frame rates 10 MHz). Molecular simulations used give rate preservation throughout free expansion impact process, highlighting challenges retrieval. Raman spectroscopy data show graphitic signatures on a plate confirming that shock-compressed PS is transformed. First electron microscopy analyses solid plates yield an outstanding number different spherical-like objects in size range between ten(s) hundreds nanometres, which one type two potential candidates identified. The origin some can unambiguously be assigned, while history others remains speculative.