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

Summary

Excitation functions were measured by the stacked–foil technique for ^natSr(p, xn)^88,87m,gY reactions from threshold up to 25 MeV. From the measured cross sections integral yields of ⁸⁸Y, ^87mY and ^87gY were calculated. The optimum energy range for the production of ⁸⁸Y is E_p = 14 → 9 MeV; the ⁸⁸Y yield amounts to 1.75 MBq (47.3 µCi/µA·h) and the ⁸⁷Y and ^87mY 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 ⁸⁶Y and ⁸⁸Y has been carried out more than 15 times each using the (p, n) reaction. In the former case 96.3% enriched ⁸⁶SrCO₃ was used as target material, and in the latter ^natSrCO₃. The method of separation of radioyttrium has been improved. After coprecipitation with La(OH)₃, cation–exchange HPLC was applied to isolate radioyttrium from the carrier lanthanum. The radionuclidic and chemical purities of the products were good. Batch yields of ⁸⁶Y and ⁸⁸Y amounted to about 3.5 GBq and 35 MBq, respectively.