Production of 77Kr and 79Kr for medical applications via proton irradiation of bromine: excitation functions, yields and separation procedure.

Abstract Excitation functions were measured for the formation of both 77 Kr and 79 Kr by interaction of protons with bromine of natural isotopic composition. The theoretical yields are 62.8 mCi/μAh for 77 Kr in the energy range from 45 to 32 MeV, with 1.5% 76 Kr and 11.7% 79 Kr impurities, and 14.9 mCi/μAh for 79 Kr in the energy range of 45 to 0 MeV, respectively. The experimental yield after dry distillation separation of the krypton isotopes from irradiated NaBr targets, lies between 40 and 60% of the theoretical ones. Below the melting point of NaBr, krypton is released by diffusion, caused by lattice defects in the target material.