Fig. 4.

Representative curve showing the ${}^{\mathrm{sub}}{\tau }_{1/2}$ calculation from a smoothed DCS curve superimposed over the raw data—smoothed curves were obtained by applying a logarithmic filter to the raw data. ${}^{\mathrm{sub}}{\tau }_{1/2}$ values were calculated by finding the point where the autocorrelation ($g_2$) curve had decayed to halfway between its maximum and minimum value. Maximum (minimum) $g_2$ values were estimated by calculating the average $g_2$ value over a predefined range at the top (bottom) of the curve. A distribution of ${}^{\mathrm{sub}}{\tau }_{1/2}$ values was obtained using different sets of feasible top and bottom ranges. A representative ${\tau }_{1/2}$ value for each scan was calculated as the average over the distribution of ${}^{\mathrm{sub}}{\tau }_{1/2}$ values.