| dc.description |
We have produced two vertically well separated zones of lithium vapour above the evaporation source in a confined noble gas atmosphere by setting an appropriate condition for the gas evaporation. Optical extinction spectra of lithium atoms, dimers and clusters were obtained by time-resolved and space-resolved measurements after the beginning of the evaporation. Also, vapour species in each zone were selectively excited using laser light and the emission spectra were measured. Some of the observed spectra were compared with theoretical ones, and information on the following points was derived: (i) the mechanism of lithium cluster and microcrystal growth in the gas evaporation method, (ii) the size trend of the collective mode resonance of the valence electrons, (iii) the excitation energy transfer between lithium vapour species, (iv) the structure of the vapour zone and (v) the mechanism of laser photofragmentation of clusters. |
