Radiochemical studies relevant to the production of 86Y and 88Y at a small-sized cyclotron

Excitation functions were measured by the stacked-foil technique for nat Sr(p, xn)Y-88.87m.g reactions from threshold up to 25 MeV. From the measured cross sections integral yields of Y-88, Y-87m and Y-87g were calculated. The optimum energy range for the production of Y-88 is E-p = 14 --> 9 MeV; the 88Y yield amounts to 1.75 MBq (47.3 muCi/muA.h) and the Y-87 and 87(m)Y impurities to 2.0 and 4.4%, respectively. The isomeric cross section ratio for the pair 87m,gY was determined as a function of incident proton energy and the results are discussed in terms of the spins of the two isomeric states involved. Medium scale production of both Y-86 and Y-88 has been carried out more than 15 times each using the (p, n) reaction. In the former case 96.3% enriched (SrCO3)-Sr-86 was used as target material, and in the latter (SrCO3)-Sr-nat. The method of separation of radioyttrium has been improved. After coprecipitation with La(OH)(3), cationexchange HPLC was applied to isolate radioyttrium from the carrier lanthanum. The radionuclidic and chemical purities of the products were good. Batch yields of Y-86 and Y-88 amounted to about 3.5 GBq and 35 MBq, respectively.