Separation of carrier-free ytterbium and thulium produced in 80 MeV 12C6+ irradiated gadolinium foil target by liquid-liquid extraction with HDEHP.

Heavy ion activation of natural gadolinium foil with 80 MeV 12C6+ results in the formation of carrier-free ytterbium isotopes, 165,166,167Yb and their corresponding decay products, 165,166,167Tm, in the matrix. Carrier-free ytterbium and thulium isotopes have been separated quantitatively from the bulk target matrix gadolinium by employing di-(2-ethylhexyl)phosphoric acid (HDEHP) as a liquid cation exchanger.