Experimental studies and nuclear model calculations on proton-induced reactions on Se, Se and Se with particular reference to the production of the medically interesting radionuclides Br and Br

Excitation functions of the reactions ^natSe(p,x)^75,76,77,82Br, ⁷⁶Se(p,xn)^75,76Br, ⁷⁶Se(p,x)⁷⁵Se and ⁷⁷Se(p,xn)^76,77Br were measured from their respective thresholds up to 40 MeV, with particular emphasis on data for the production of the medically important radionuclides ⁷⁶Br and ⁷⁷Br. The conventional stacked-foil technique was used. The samples were prepared by a sedimentation process. Irradiations were performed using the compact cyclotron CV 28 and the injector of COSY, both at the Research Centre Jülich. In order to validate the data, nuclear model calculations were performed using the code ALICE-IPPE which is based on the preequilibrium-evaporation model. Good agreement was found between the experimental and theoretical data, except in the high-energy region where the calculated data were somewhat higher. All the measured excitation curves were compared with the data available in the literature. From the experimental data the theoretical yields of all the investigated radionuclides were calculated and plotted as a function of proton energy. The calculated yield of ⁷⁷Br from the ^natSe(p,x)⁷⁷Br process over the energy range E_p=25→15 is 72.7 MBq/μA h and from the ⁷⁷Se(p,n)⁷⁷Br reaction over E_p=15→6 MeV it is 86.2 MBq/μA h. The yield of ⁷⁶Br from the ⁷⁶Se(p,n)⁷⁶Br reaction for E_p=15→8 is 360.1 MBq/μA h and from the ⁷⁷Se(p,2n)⁷⁶Br reaction for E_p=28→18 MeV it is 879.2 MBq/μA h. The radionuclidic impurity levels are discussed.