Nb and Rb neutron resonances and radiation widths of medium-mass nuclei

The neutron resonance parameters for niobium and rubidium in the energy range up to 400 eV and up to 1300 eV, respectively were determined by measuring the transmission, capture, scattering and self-indication. The obtained values of the radiation widths for niobium s and p wave levels coincide within the measurement error. The radiation width for the magic nucleus of Rb 87 is less than that for the nonmagic Rb 85 . The experimental data on the radiation widths of medium nuclei show a minimum in the region of the closed shell with the number of neutrons equal to 50.