Extraction chromatographic separation of carrier-free Tb and Pm generated in (p,xn)-type nuclear reactions

The nuclear reactions of (p, xn)-type, E_p=100–120 MeV, on Gd and Nd have been used to produce highly radioactive preparations of Tb and Pm enriched with neutron-deficient isotopes. Under comparable conditions the yields of practically all isotopes are considerably higher than in Tb and Gd spallation reactions at E_p=660 MeV. The radioactivity of screened¹⁵⁴Tb and¹⁵⁶Tb isotopes has been increased more than 40 times. Tb and Pm were separated from gram amounts of the target-elements by the extraction chromatography technique with undiluted di-(2-ethylhexyl) phosphoric acid as stationary phase. The radiochemical method developed was also applied to separate the radiochemically pure preparation of¹⁶¹Tb from Gd oxide irradiated with thermal neutrons.