In-beam gamma-ray spectroscopy and shell-model description of Y-85,Y-86 isotopes

The nuclei Y-85 and Y-86 (were studied in two series of experiments conducted by using the heavy-ion reactions Ge-76(N-14, 4n)Y-86 and Cr-52(Cl-37, 2pxn)Y-85,Y-86. The analysis of double and triple coincidences of gamma rays along with the investigation of angular distributions led to the extension of the level schemes of the Y-85 and Y-86 nuclei to spins and excitation energies higher than observed in previous experiments. In addition, a few new levels with low spins and excitation energies were identified in both nuclei. fit order to better understand the nuclear structure of these isotopes. shell-model calculations were carried out considering a valence space formed by the proton and neutron orbitals f5/2, p3/2, P1/2, and g9/2.
This work was partially supported by the Romanian National Authority for Scientific Research under the contracts No. ID-117/2007 and ID-362/2007 and by the European Community FP6 under contract EURONS No. RII3-CT-2004-506065. The authors would like to thank G. Manente and M. Loriggiola of the Target Laboratory at the National Laboratory of Legnaro (INFN-LNL) for preparing the targets for both series of experiments. Many thanks are extended to the operating crews of the XTU and FN Tandem accelerators at INFN-Legnaro and NIPNE-Bucharest, respectively. C.R. also wishes to thank his wife, Gra¸tiela, for critically reviewing the manuscript and for her unceasing support.