Ion Imaging Method Optical Dissociation And Photoionization

Ion imaging techniques has become an important method in the research of photodissociation dynamics since it was first introduced several years ago. During the thesis studies, the author participated in building up the first ion imaging system in China and developed a series of programs to acquire and analyze image results.In this thesis, our experimental apparatus was introduced first. We endeavored to make the device multifunctional (mass spectrum, photoelectron spectrum and Doppler profile). We also presented a new iterative Abel inversion algorithm to improve the precision of results.As a calibration, we first employed this setup to study the photoelectron spectrum of iodine atom produced by photolysis"of .,I at 277nm. It involves two processes: Taking advantage of the improved Abel inversion, we have gotten a relative resolution of 3.9% and revealed the later process involved two different pass ways.The images of H atom dissociated from H2S, C2HSSH, j'-C,H7SH and C3H7SH at 243nm were also recorded. Based on the ab initiocalculation results, the vibrational state distribution of mercaptan radicals was analyzed. It indicates the behavior of mercaptan photolysis is mainly determined by the interaction of atoms instead of the mass of molecules. Dissociation energy are also calculated.