Silicon Radiation at a Shock Compression Pressure of 68 GPa and During Unloading into a Vacuum

In this study, the brightness temperatures of silicon shock-compressed to a pressure of P = 68 GPa and the evolution of its temperature during unloading are measured. The measurements were carried out in the infrared range Δλ 1 = 1.1–1.7 µm, in which silicon is optically transparent, and in the visible range Δλ 2 = 0.32–1.06 µm. The isentropic unloading of shock-compressed silicon into a vacuum is accompanied by an anomalous increase in the observed temperature.