Excitation Functions of Neutron Threshold Reactions on Some Isotopes of Germanium, Arsenic, and Selenium in the 6.3- to 14.7-MeV Energy Range

Cross sections were measured for the ⁷⁵As(n,p)⁷⁵Ge, ⁷⁵As(n, α)⁷²Ga, ⁷⁵As(n,2n)⁷⁴As, ⁷⁴,⁷⁶,⁷⁸Se(n,p)^74,76,78As, ^78,80Se(n,α)^75,77Ge, ^72,73,74Ge(n,p)^72,73,74Ga, and ^70,76Ge(n,2n)^69,75Ge reactions over the 6.3- to 14.7-MeV neutron energy range. Samples of As₂O₃, selenium, and germanium or GeO₂ of natural isotopic abundance were used. The neutrons were produced via the D(d,n)³He reaction using a deuterium gas target at a variable energy cyclotron (E_n = 6.3 to 11.9 MeV) and via the T(d,n)⁴He reaction using a solid titanium-tritium target at a neutron generator (E_n = 14.7 MeV). The activation technique was used in combination with high-resolution gamma-ray spectroscopy. The experimental excitation functions are well reproduced by the nuclear model calculations, based on statistical multistep reaction theory.