Key words: statistical physics, critical phenomena, Rayleigh light scattering
For the first time, the temperature dependence of the density variance and the correlation length of critical density fluctuations is determined from the experimental data on small-angle light scattering by critical CO2. It is found that at critical density of CO2 in the temperature range 10-8 Tc < |T - Tc| < 10-4 Tc (where Tc is the critical temperature) the correlation length of density fluctuations decreases by 20 % as the critical point is approached. The value of density variance shows no power-law-type divergence: it remains practically constant in the temperature ranges T > Tc and T < Tc, but undergoes a 25 % stepwise change when passing through the critical point, likely due to the peculiarities of the experiment setting up.
doi:10.34984/SCFTP.2021.16.1.006