SPECTROSCOPY OF PO-198,PO-199

Excited states in Po-198,Po-199 have been studied by in-beam gamma-ray spectroscopy. These nuclei were produced in the 4n and 5n reaction ch annels for 115 MeV Ne-20 on W-183-targets. Multipolarities and mixing ratios of gamma-transitions were determined from DCO-ratios, leading t o spin/parity assignments. In Po-198, gamma-cascades have been observe d above several excited levels that are similar to the vibration-like structure built on the ground state. In Po-199, the coupling of the od d i(13/2) neutron seems to favor the spherical shape of the even core; no levels resembling the intruder states of the even nuclei are found . A semiquantitative evaluation of the cross-sections for nuclei produ ced in fission and multi-particle transfer is presented.