Level structure of 164Dy from the (n, n′γ) reaction

Abstract

By employing a beam of reactor fast neutrons, gamma-ray spectra and angular distributions of gamma rays with respect to the neutron-beam axis were measured in the reaction ¹⁶⁴Dy(n, n′γ). The scheme of levels and gamma transitions in ¹⁶⁴Dy was composed on the basis of data published earlier and new levels, rotational bands, gamma transitions, and multipole-mixing parameters. It is concluded that the scheme of J = 0–4 levels is complete up to the excitation energy of 1.95 MeV. The commonly accepted rule in constructing K_n^π = 0₂⁺ and 1₁⁺ rotational bands is found to be violated. The nature of the 2⁺ level at the energy of 1796.68 keV is discussed.