Ion Desorption Reaction of Surface Admolecules Induced by Synchrotron Radiation

Studies of surface photochemical reactions induced by core excitation have developed with the advance of synchrotron radiation technique over a range extending from vacuum ultraviolet to soft X-ray. Studies of the photon stimulated ion desorption (PSID) have been carried out mainly on the basis of the initial excitation energy dependence of the desorption yield. In particular, site-specific reactions have been found in PSID following core electron excitation. This is very interesting from the viewpoint of the control of chemical reactions using monoenergetic photo-excitation. The Auger stimulated ion desorption (ASID) mechanism is widely proposed as a model of PSID. As the Auger final state is directly related to the ion desorption in this model to elucidate the PSID mechanism, it is essential to get the information about the Auger final state. In this article, we have described about PSID of formic acid induced by carbon core excitation using ion TOF method and about PSID of condensed H2O induced by oxygen core excitation using Auger electronphotoion coincidence (AEPICO) method.