Ultrafast dynamics and dissociative ionization of CS_2 molecules studied via the femtosecond pump-probe method  

作　　者：ZHANG DongDong FAN Zhen SUN ErPing ZHANG JunFeng LIU Hang XU HaiFeng JIN MingXing DING DaJun 

机构地区：[1]Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China

出　　处：《Chinese Science Bulletin》2011年第9期855-861,共7页

基　　金：supported by the National Natural Science Foundation of China (10874056 and 10534010)

摘　　要：The ultrafast dynamics and dissociative ionization of CS2 were studied using the pump-probe method with time-of-flight mass spectroscopy. The transient behavior of both parent ion (CS2+) and fragment ions (S+ and CS+) was observed. It was found that all the ionic signals decay exponentially with lifetimes that were different for delay times, t>0 and t<0, which can be attributed to the evolution of different Rydberg states pumped by 267-nm and 400-nm laser pulses. The lifetimes of two Rydberg states were obtained simultaneously from one fitting of the transients. The fragment ions were produced by the dissociation of CS2+, and it is suggested that the final ionic state is the C2Σg+ state of CS2+ based on the measured S+/CS+ branching ratio. The S+/CS+ ratio is dependent on the delay time of the two lasers, indicating that the dissociation process of CS2+ is related to the evolution of the intermediate Rydberg state.The ultrafast dynamics and dissociative ionization of CS2 were studied using the pump-probe method with time-of-flight mass spectroscopy. The transient behavior of both parent ion （CS2^＋） and fragment ions （S^＋ and CS^＋） was observed. It was found that all the ionic signals decay exponentially with lifetimes that were different for delay times, t〉0 and t〈0, which can be attributed to the evolution of different Rydberg states pumped by 267-nm and 400-nm laser pulses. The lifetimes of two Rydberg states were ob- tained simultaneously from one fitting of the transients. The fragment ions were produced by the dissociation of CS2^＋, and it is suggested that the final ionic state is the C2Eg＋ state of CS2^＋ based on the measured S^＋/CS^＋branching ratio. The S^＋/CS^＋ ratio is dependent on the delay time of the two lasers, indicating that the dissociation process of CS2^＋ is related to the evolution of the intermediate Rydberg state.

关 键 词：泵浦探测法 超快动力学 解离电离 分子离解 CS2 飞秒 碎片离子 二硫化碳 

分 类 号：TQ610.1[化学工程—精细化工] Q945.11[生物学—植物学]