Photoabsorption, photoionization, and neutral dissociation cross-sections of hydrocarbon molecules; Physicochemical aspects of molecular processes in fusion edge plasmas

Hatano, Yoshihiko

A survey is given of recent progress in the measurements of absolute cross-sections for photoabsorption, photoionization, and neutral dissociation of simple and complex molecules in the vacuum ultraviolet region, where a major part of their oscillator strength distributions due to the interactions of photons with molecules exists. Emphasis is placed on the discussion of the neutral dissociation(i.e., the dissociative excitation)of these molecules which has been considered as the most processes to be studied experimentally. From the viewpoints of the molecular processes in fusion edge plasmas, simple hydrocarbon molecules are chosen for the discussion of the measured cross-section values and the spectroscopy and dynamics of the corresponding processes. It has been shown that these optical cross-section data are of great importance to understand the fundamental processes, not only in photon collision induced reactions but also in electron collision induced reactions.