Gamma radiation from the (n,n'γ) reaction on even-even Er isotopes

On fast neutrons beam γ-spectra from the (n, n', γ) reaction of inelastic neutron scattering on the supC164, 166, 168, 170)Er isotopes are measured. The greater part of observed γ quanta is placed in the tabulated decay schemes. In the scheme energies and intensities of transitions are indicated. Assumptions on initial level from which the transition begins, are made. The excited level analysis is performed. On the example of the well studied 168Er nucleus it is shown that the majority of known levels has been manifested up to E=2 MeV including states with spin 8 of the ground band and 7 and 8 of the γ-vibrational band. In the 166Er for the first time the discharge of levels known earlier only from nuclear reactions has been found. The band with Ksup(π)=0sup(+) at 1703 keV level is suggested. The absence of the 1159 keV 2+ level is shown. Vast new information is obtained on 170Er levels. The levels with I=5.6 and 7 of the γ band are found, the bands based on levels 1266,4, 1-, 1217,4, 3+, 1324,3 0+, 1416,1, 2+ and 1506,3 keV, 4+ are revealed. Besides corresponding rotation levels a series of states is proposed. The 164Er level scheme is considerably added. The 7sub(γsup(+) level as well as bands based on 1189,3, 4-, 1386,1, 1- and 1568,6 keV, 3-, and other states have been found. All these data widen information on the structure of deformed nuclei, regularities in level energies, their discharge and state populations in the (n, n', γ) reaction