PROMPT GAMMA-RAY SPECTROSCOPY OF THE MO-104 AND MO-108 FISSION FRAGMENTS

The level structures of the neutron-rich Mo-104 and Mo-108 nuclei have been investigated by observing prompt gamma rays emitted in the spont aneous fission of Cm-248 With the EUROGAM spectrometer. Levels with sp ins up to 12HBAR have been observed and gamma branching obtained. The data can be satisfactorily described when Mo-104,Mo-108 are considered as axially symmetric nuclei: in Mo-104, rotational bands based on the ground state, the one-phonon and the two-phonon gamma-vibrational sta tes and a quasiparticle state have been observed, whereas in Mo-108 th e information is limited to the yrast band and the one phonon gamma ba nd.