Competition Between Two Excitation-dissociation Channels for Molecular Ions  

分子离子双激发解离通道的竞争

作　　者：来丽坤[1] 张立敏[1] 杨茂萍[1] 周丹娜[1] 

机构地区：[1]中国科学技术大学化学物理系,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2009年第3期223-227,339,共6页化学物理学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China （No.20673108）.

摘　　要：When the molecular ions XYZ＋ （XY2＋） are excited simultaneously from an electronic state E0 into two higher electronic states Ea and EZ with supervened dissociation or predisso- ciation, competition between the α and β excitation-dissociation channels occurs. A the- oretical model is provided to deal with the competition of the two excitation-dissociation channels with more than two kinds of ionic products for XYZ＋ （XY2＋）. Supposing that the photo-excitation rates of two states Eα and Eβ are much less than their dissociation or pre-dissociation rates, a theoretical equation can be deduced to fit the measured data, which reflects the dependence of the product branching ratios on the intensity ratios of two excitation lasers. From the fitted parameters the excitation cross section ratios are obtained. In experiment, we studied the competition between two excitation-dissociation channels of CO^2＋. By measuring the dependence of the product branching ratio on the intensity ratio of two dissociation lasers and fitting the experiment data with the theoretical equation, excitation cross section ratios were deduced.

关 键 词：Molecular ion Competition of two excitation channel PHOTODISSOCIATION Excitation cross section ratio 

分 类 号：O641.1[理学—物理化学] O562.5[理学—化学]