Nuclear collective states in <super>110</super>Cd, <super> 192</super>Pt, <super>192</super>Os and <super>166</super>Er

Abstract

The properties of the low-lying energy states of 110Cd, 192Pt, 192Pt and 166Er following the radioactive decays of 110mAg, 192Ir and 166mHo were investigated.

Two high resolution Ge(Li) detectors, one intrinsic germanium detector and a Compton suppression system were employed for the measurements of the gamma-ray energies and relative intensities, gamma-gamma coincidence measurements using a conventional fast-slow coincidence technique were performed by coupling the Ge(Li) detectors to a 4096X4096 Dual Parameter Data Collection System.

The level schemes of the above nuclei were authenticated on the basis of the coincidence measurements. The properties of the levels are discussed, logft values and branching ratios deduced, spins and parities assigned and the lifetime for the first excited state of 166Er was determined using the method of delayed coincidence between a plastic and a NaI(Tl) detector.

Each established level scheme is compared with the theoretical predictions of current nuclear models, notably the interacting boson model (IBM). The Program-Package PHINT was run on the University of London CDC 7600 Computer in order to calculate energies and transition rates on the basis of this model. The nuclei investigated test the SU(5) limit for 110Cd, the O(6) limit for 192Pt and the SU(3) --- O(6) transitional region for 192Os and 166Er.