SPECTROSCOPY OF NEUTRAL AND CHARGED METAL-CLUSTERS

The technique of supersonic molecular beams is used to investigate alkali clusters by means of resonant Two-Photon-Ionization (TPI). Under specific stagnation conditions the clusters are sufficiently cooled to exhibit well resolved vibrational structures. The interpretation of highly excited Rydberg states permits a determination of the molecular constants of the related cluster ions. All excitation and ionization processes, however, exhibit strong fragmentation channels. With growing particle size, therefore, a proper assignment of the observed spectra to the original unfragmented particle becomes more and more difficult. For this reason an experiment was established, which allows the spectroscopic investigation of single size particles.