Correlation Range and Compressibility of Xenon near the Critical Point

From the magnitude and angular dependence of the intensity of light scattered from xenon near its critical point we have measured the Ornstein-Zernike long-range correlation length $\xi$ and the reduced compressibility ${\left(\frac{\partial \rho }{\partial \mu }\right)}_T$. We find $\xi =(3.0\mathrm{}\pm 0.10){\epsilon }^{-0.58\mathrm{}\pm 0.05}$ Å and ${\left(\frac{\partial \rho }{\partial \mu }\right)}_T=(1.43\mathrm{}\pm 0.06)\times {10}^{-9\mathrm{}}{\epsilon }^{-1.21\mathrm{}\pm 0.03}$ ${\mathrm{g}}^2$/erg ${\mathrm{cm}}^3$ along the critical isochore, and ${\left(\frac{\partial \rho }{\partial \mu }\right)}_T=(0.346\mathrm{}\pm 0.01)\times {10}^{-9\mathrm{}}{\epsilon }^{-1.21\mathrm{}\pm 0.02}$ ${\mathrm{g}}^2$/erg ${\mathrm{cm}}^3$ along the coexistence curve, with $\epsilon \equiv \frac{|T-T_c|}{T_c}$. Using our results, we have compared the predictions of the Kawasaki-Kadanoff-Swift mode-mode coupling theories with measurements of the thermal diffusivity in xenon.