SNO+ scintillator cocktail studies using an ${}^{90}$Y source

We present the design of an ${}^{90}$Y calibration source and its manufacturing procedure, that has been implemented in the University of Sussex radioactive laboratory. The radioactive source was first tested at the University of Sussex using a small scintillator cocktail sample. Further measurements were performed at the University of Pennsylvania using a larger volume of the scintillator cocktail. The results of both studies are presented and discussed.