Dipole strength in ⁸⁰Se below the neutron-separation energy for the nuclear transmutation of ⁷⁹Se

Abstract

Abstract. The γ -ray strength function (γ SF) in 80 Se is an important parameter to estimate the neutroncapture cross section of 79 Se which is one of the long-lived fission products (LLFPs). Until now, the γ SF method was applied for 80 Se only above the neutron-separation energy (S n ) and the evaluated 79 Se(n,γ ) cross section has an instability caused by the GSF below S n . We studied the dipole-strength distribution of 80 Se in a photon-scattering experiment using bremsstrahlung produced by an electron beam of an energy of 11.5 MeV at the linear accelerator ELBE at HZDR. The present photoabsorption cross section of 80 Se was combined with results of (γ ,n) experiments and are compared with predictions usinmg the TALYS code. We also estimated the 79 Se(n,γ ) cross sections and compare them with TALYS predictionms and earlier work by other groups.