Cross-section measurements and production of ⁷² Se with medium to high energy protons using arsenic containing targets

Experiments were performed to evaluate production of ⁷² Se, parent radionuclide of the positron emitter ⁷² As, at high energy at the Brookhaven Linac Isotope Producer (BLIP). Excitation functions for ⁷⁵ As(p, xn) ^72/75 Se in the 52-105 MeV energy range were measured by irradiating thin gallium arsenide (GaAs) wafers. Maximum cross section value for the ^nat As(p, 4n) ⁷² Se reaction in the energy range was 103±9 mb at 52±1 MeV. Production size GaAs and arsenic metal (As°) targets were irradiated with 136 μA and 165 μA beam current possessing an initial Linac energy of 117 MeV. A total of 3.77±0.1 GBq (102±3 mCi) of ⁷² Se was produced from a GaAs target at a calculated target entrance energy of 105.4 MeV, and 13.8±0.3 GBq (373±8 mCi) of ⁷² Se from an As° target at a calculated incident energy of 49.5 MeV irradiated for 116.5 h and 68.9 h, respectively.