The 180Ta production puzzle and the classical s-process Original Research Article

We reproduced the observed solar abundance of 180Tam and 180W in the classical s-process taking into account neutron captures feeding 180Ta and the intermediate state below 1.1 MeV that enables photon coupling between the isomer and the ground state. Intermediate states in 180Ta were analyzed in the framework of the quasiparticle- plus-phonon model and the particle-rotor model.