Experimental studies on Feshbach-type resonances on rare gas clusters

点击翻译按钮获取中文摘要

The purpose of this study is to confirm the existence of the Feshbach-type resonances on rare gas clusters. This resonance has been well known in rare gas atoms in gas phase, and has been found also in rare gas solids in 1993. It is not obvious whether the resonance occurs in the rare gas clusters because of its finite size.During the term of this study, we have obtained following results.・Energy levels of the 1st order surface and bulk excitons have been determined experimentally for Kr clusters with the size of 1400 atoms.・At an incident electron energy of 50eV, only the surface exciton peak has been observed, while the bulk peak appeared at incident electron energies of 100 and 200 eV.This result was explained using a mean free path (MFP) of an electron in Kr solids, i.e., the MFP of an electron with 50eV energy is comparable with the nearest neighbor distance in Kr crystal which results in higher sensitivity on the surface exciation, while MFP of 100 and 200 eV electrons is a few times longer than the nearest neighbor distance, resulting in the possibility of exciting the atoms in the bulk.・Feshbach resonances have not been observed for Kr clusters with the size of 1000 to 2000 atoms within our sensitivity of the measurements.