TIME RESOLVED SPECTROSCOPY OF SHOCK COMPRESSED LIQUID CARBON DISULFIDE

Techniques have been developed for obtaining time resolved absorption spectra of liquids as they are compressed by reverberating shock waves to pressures as high as 130 kbars. Spectral resolution of 30 (ANGSTROM) and time resolution of 30 nsec have been achieved. Spectral range is 2500 to 7000 (ANGSTROM).;These techniques have been applied to carbon disulfide. Reflection experiments showed considerable reflection from the sample at pressures of 83, 99, and 123 kbars. In transmission experiments, as the first shocks at 5 to 19 kbars, reverberated through the sample, the regions of absorption expanded stepwise toward longer wavelengths. Up to at least 58 kbars, the carbon disulfide remained transparent at wavelengths longer than about 4000 (ANGSTROM). In experiments over 120 kbars, some decay of reflectivity or transmission was observed. This may be an indication of a chemical reaction which is believed to occur in shock compressed carbon disulfide. This reaction is not expected at pressures under 120 kbars in reverberation experiments.;Liquid samples are contained in sapphire cells and shocked by impacting the face of the cell with a sapphire impactor mounted in a gas gun projectile. In one variation, reflection experiments, light from a xenon flashlamp is focused into the back of the cell, possess through the cell and impactor, is reflected by an aluminum coating, and again passes through the impactor and cell. In a second variation, transmission experiments, the flashlamp is mounted in the projectile so light passes only once through the impactor and cell. In both variations the light beam is dispersed in wavelength by a diffraction grating and in time by a rotating mirror streak camera.