title: Experimental studies and nuclear model calculations on proton-induced reactions on (nat)Se, (76)Se and (77)Se with particular reference to the production of the medically interesting radionuclides (76)Br and (77)Br.
abstract: Excitation functions of the reactions (nat)Se(p,x)(75,76,77,82)Br, (76)Se(p,xn)(75,76)Br, (76)Se(p,x)(75)Se and (77)Se(p,xn)(76,77)Br were measured from their respective thresholds up to 40 MeV, with particular emphasis on data for the production of the medically important radionuclides (76)Br and (77)Br. 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 (77)Br from the (nat)Se(p,x)(77)Br process over the energy range E(p)=25-->15 is 72.7 MBq/microAh and from the (77)Se(p,n)(77)Br reaction over E(p)=15-->6 MeV it is 86.2 MBq/microAh. The yield of (76)Br from the (76)Se(p,n)(76)Br reaction for E(p)=15-->8 is 360.1 MBq/microAh and from the (77)Se(p,2n)(76)Br reaction for E(p)=28-->18 MeV it is 879.2 MBq/microAh. The radionuclidic impurity levels are discussed.
authors.affiliation: Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, Jülich D-52425, Germany.
authors.forename: H E
authors.initials: HE
authors.lastname: Hassan
authors.forename: S M
authors.initials: SM
authors.lastname: Qaim
authors.forename: Yu
authors.initials: Y
authors.lastname: Shubin
authors.forename: A
authors.initials: A
authors.lastname: Azzam
authors.forename: M
authors.initials: M
authors.lastname: Morsy
authors.forename: H H
authors.initials: HH
authors.lastname: Coenen
mesh_terms: D001967:Bromine Radioisotopes / Q000032:analysis*; D007554:Isotopes; D011868:Radioisotopes; D012643:Selenium / Q000032:analysis*
chemical_list: D001967:Bromine Radioisotopes; D007554:Isotopes; D011868:Radioisotopes; D012643:Selenium