Polarization effects in electron attachment to metallic clusters

New calculations of the low-energy free-electron attachment cross section t o neutral and charged metallic clusters are reported. We include all the bo und states of the negative ion as well as Rydberg series of neutral cluster targets as possible final states for attachment and calculate the electron attachment cross sections. The influence of the dynamic core polarization on the capture process is studied. Quadrupole contributions are found to pl ay a more important role than in the optical spectra as cluster size increa ses.