ISOMER SPECTROSCOPY OF HEAVY NEUTRON-RICH NUCLEI PRODUCED IN RELATIVISTIC FRAGMENTATION

We present an overview of results obtained at the Fragment Separator of GSI Darmstadt where beams of 238U and zo8Pb at energies of 1 GeV/nucleon were used to study microsecond isomers in neutron-rich heavy nuclei. Selected examples of new isomeric states identified in these experiments will be given. A systematic study of the population probabilities of isomeric states will be discussed. Measured values of the isomeric ratio will be compared with the estimates from a simple model using the sharp cut-off approximation.