Resonant excitation of the reactionTam180(γ,γ’)180Ta

Irradiation of Ta with a superconducting linear accelerator has provided data for the characterization of the reaction ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}_{}^{\mathit{m}}{}_{}{}^{}$(γ,γ’ ${)}^{180}$Ta. The depopulation of the isomer ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}_{}^{\mathit{m}}{}_{}{}^{}$ via an intermediate state or narrow band of states near 2.8 MeV has been found with an integrated cross section of 1.2×${10}^{\mathrm{-}25}$ ${\mathrm{cm}}^2$ keV. This large value exceeds, by nearly an order of magnitude, known cross sections for (γ,γ’) reactions producing isomers of other species. Another intermediate state or narrow band is also indicated by the data at an energy 0.6 MeV higher.