Collisional Energy Transfer With The Participation Of The Excited Cs Atoms

The excited states of alkali atoms and molecules are low, and their density of energy levels is high. They offer the possibility of developing the newly tunable high-power laser. The domestic and international scholars are very interested and pay much attention to it in recent years.This text is divided into five parts, In the first three chapters the theoretical overview is introduced, including the structure of energy levels of atoms and molecules, the spectroscopy and the collisions of the atoms and molecules. The researching methods and the experimental techniques are introduced in chapter 4. In chapter 5 we have reported the collisional energy transfer with the participation of the excited Cs atoms using the technique of laser-induced fluorescence spectroscopy. The contents include:(1). Ratios for branching into the fine-structure levels of the Cs 6P multiplet, as a consequence of an optical collision with N2 and He atoms are reported. We obtained the relevant values of cross sections. We have eliminated the influence of Rayleigh scattering and got more accurate information about the collisional energy transfer by adopting the method of non-resonance excitation.(2). An experimental study of energy transfer collisions, Cs(6P)+Cs(6S)+He→Cs(5D)+Cs(6S)+He, at thermal energies, has been carried out. The three-body collision rate coefficient is obtained. This rate coefficient has not been reported.(3). An experimental study of cesium energy pooling collision, 6P3/2+6P3/2→6DJ+6S, has been carried out. The cross sections for 6D5/2 and 6D3/2 are reported. The results are disussed in relation to those of other experiments.