Vibrational Excitations in the Even-mass Cadmium Isotopes

Abstract

The backward-angle scattering of 4He ions from the even-A stable isotopes of cadmium has been investigated at bombarding energies above the Coulomb barrier. At 17· 5 MeV bombarding energy the gross features of the spectra are strikingly regular from one isotope to another, and this may be interpreted in terms of vibrational excitations. Other evidence is presented to support the concept of a uniform vibrational character for all the even-A stable cadmium isotopes. The spectra show no significant evidence for previously unreported levels in the two-quadrupole-phonon excitation region. However, a new level is found at 2304 ± 4 keY in l06Cd.