DENSITY-MEASUREMENT FOR FLUID SELENIUM BY THE X-RAY ABSORPTION METHOD

The density of fluid Se was measured at temperatures up to 1670°C and pressures up to 700 bar by means of X-ray absorption. This is the first measurement which extends over the entire liquid-gas range, including the supercritical region. For the measurement specially constructed sapphire cell was used. Fluid Se has a critcal point at Tc=1630-30+0°C, Pc=380±2bar and ρ{variant}c=1.85±0.05 g/cm3. The equation of state and its derivatives such as isothermal compressibility and thermal expansion coefficient are presented. © 1990.