(Top) $τp,He−I*$ as a function of heating power measured from the decay of a perturbative helium puff using the 468.6 nm line. The solid lines indicate a power function fit for each configuration. (Middle) $τp,He−II*$ as a function of heating power measured from the decay of a perturbative helium puff using the 667.8 nm line. The solid lines indicate a power function fit for each configuration. (Bottom) $τp,H*$ as a function of heating power measured from the decay of the interferometer line-averaged density. The values of $τp,H*$ are negative because the plasma density is rising rather than falling. The solid lines indicate a power function fit for each configuration.