ELECTRONIC EXCITATION, DECAY AND PHOTOCHEMICAL PROCESSES IN RARE-GAS CLUSTERS

An overview of processes of electronic excitation and the subsequent f ollowing decay in clusters is presented. Pure rare gas clusters (Xe-Ne ) are chosen as model systems for non-metallic clusters, Selective pho to-excitation with synchrotron radiation offers the possibility to stu dy a variety of different decay and relaxation processes (exciton trap ping, desorption of electronically excited species) depending both on the cluster size and of the excitation energy. Special emphasis is giv en to the role of energy transfer, and in particular, vibrational ener gy flow, radiative and non-radiative electronic relaxation. Some recen t results on the decay processes in He clusters are given in the last part of the article. Decay processes in He clusters differ remarkably from that observed in the heavier rare gas clusters.