Application of synchrotron radiation to photoionization spectroscopic analysis of molecule and molecular cluster

The recent improvement in techniques for supersonic molecular beam not only has permitted the production of molecular clusters and van der Waals molecules but also has facilitated spectroscopic analysis of them. Laser is currently used very widely in the area of spectroscopic research of molecules and molecular clusters. In the future, however, synchrotron radiations will have much more applications in this field. The present report briefly reviews major studies made so far for the application of synchrotron radiations to this research area. An ultraviolet synchrotron orbit radiation (UVSOR) facility constructed in Okazaki, Japan, is outlined, focusing on major features of the molecular beam type photoionization spectroscopy equipment incorporated. Concerning its application, a technique has been proposed for the determination of the threshold of H+ ion formation and the dissociation energy of the C-H bond. The report also presents and discusses some results of experiments with photoionization of water-argon, water-carbon dioxide and water-ethylene mixed clusters. (N.K.)