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

Abstract

Abstract 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.