The nuclear reactions of (p, xn)-type, Ep=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 Ep=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.