Nuclear excitation by γ rays of radioactive sources

Abstract

Nuclear isomers of stable nuclei were excited by inelastic resonance scattering of Compton-scattered γ rays from high-activity⁴⁶Sc,⁶⁰Co,⁴²Pr and²⁴Na radioactive sources. By counting isomeric transition rates, activation cross sections for thirty-five isomers were determined, some of them not previously published. Values of these cross sections lie between 0.003 and 214 μbarn. The partial level widthsμ =g Γ ₀ Γ _i Γ ⁻¹ for the transitions leading from the activation to the metastable levels, estimated for twelve activation levels belonging to eight nuclei, are between 4·10⁻⁶ and 2·10⁻⁴ eV.