Abstrakt
Spectra of gamma-rays following the neutron capture at isolated resonances of stable Gd nuclei were measured with the DANCE detector. The objectives were to obtain new information on the photon strength of Gd-153,Gd-155-159 with emphasis on the role of the M1 scissors-mode vibration.
An analysis of the data obtained clearly indicates that the scissors mode is built not only on the ground state, but also on all excited levels of the nuclei studied. Our approach allows estimating the summed scissors-mode strength Sigma B(M1)up arrow even for odd product nuclei for which conventional nuclear resonance fluorescence measurements yield only limited information.
Our data indicate that for Gd-157,Gd-159 the strength Sigma B(M1)up arrow is significantly higher compared to Gd-156,Gd-158.