$τp*$ measured in HSX in both the Edge-Island (red circles) and No-Edge-Island (gray diamonds) configurations. (Left) $τp,H*$ as a function of n_e (Right) $τp,He–II*$ as a function of n_e. Data are plotted as function of mean n_e determined from the central chord of the HSX interferometer. A single term power series fitting was used the generate a fit line, also plotted. The shaded region indicates the mean standard deviation of the measured data points from the fit line.