Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene in strong IR and UV laser fields  

作　　者：张军峰 吕航 左万龙 徐海峰 金明星 丁大军 

机构地区：[1]Institute of Atomic and Molecular Physics, Jilin University [2]Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University

出　　处：《Chinese Physics B》2015年第11期212-216,共5页中国物理B（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2013CB922200);the National Natural Science Foundation of China(Grant No.11274140)

摘　　要：Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene are studied in linearly polarized 50-fs, 800-nm and 400-nm strong laser fields using a time-of-flight mass spectrometer. It is shown that at low laser intensity, the parent ions are dominant for any one of the molecules in an 800-nm strong laser field, while extensive fragmentation is observed in a 400-nm laser field, which can be understood by the resonant photon absorption of molecular cations. The ratio of the yield of the parent ion to the yield of the total ion for each molecule is measured as a function of laser intensity in a range from 1.0 × 1013 W/cm2 to 4.0 × 1014 W/cm2, in either the 800-nm or 400-nm laser field. The results show that the fragmentation of the aromatic molecules increases significantly as the laser intensity is increased. Possible mechanisms for fragmentation in strong laser fields are discussed. Finally, the saturation intensity of ionization of the titled molecules is also determined.Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene are studied in linearly polarized 50-fs, 800-nm and 400-nm strong laser fields using a time-of-flight mass spectrometer. It is shown that at low laser intensity, the parent ions are dominant for any one of the molecules in an 800-nm strong laser field, while extensive fragmentation is observed in a 400-nm laser field, which can be understood by the resonant photon absorption of molecular cations. The ratio of the yield of the parent ion to the yield of the total ion for each molecule is measured as a function of laser intensity in a range from 1.0 × 1013 W/cm2 to 4.0 × 1014 W/cm2, in either the 800-nm or 400-nm laser field. The results show that the fragmentation of the aromatic molecules increases significantly as the laser intensity is increased. Possible mechanisms for fragmentation in strong laser fields are discussed. Finally, the saturation intensity of ionization of the titled molecules is also determined.

关 键 词：strong field ionization FRAGMENTATION BENZENE substitute benzene 

分 类 号：O561.4[理学—原子与分子物理]