Cross section measurements of 75As(α,xn)76,77,78Br and 75As(α,x)74As nuclear reactions using the monitor radionuclides 67Ga and 66Ga for beam evaluation

Abstract

Abstract For the production of the medically interesting radionuclides 76Br and 77Br cross sections of α-particle induced reactions on arsenic, leading to the formation of 76,77,78Br as well as to the non-isotopic impurity 74As, were measured from their thresholds up to 37 MeV. Sediments of elemental arsenic were used as targets and irradiated, using the established stacked-foil technique. In order to remove discrepancies of the existing literature data, the cross section ratios of the monitor nuclides 67Ga/66Ga were used for determination of the α-particle energies as well as the effective beam current through all the stacks, thus inferring the experimental cross sections. Compared with the available excitation functions the new data indicate slightly divergent curve shapes. In the case of 76Br the excitation function seems to be shifted to somewhat lower α-particle energies, and also the maximum cross section of the formation of 77Br tends to be slightly lower compared with the curve recommended to date. In the case of a re-evaluation, these new data should be taken into account, as they may contribute to enhance the accuracy of the excitation functions.