华东师范大学学报(自然科学版) ›› 2019, Vol. 2019 ›› Issue (3): 110-119.doi: 10.3969/j.issn.1000-5641.2019.03.012

• 物理学与电子学 • 上一篇    下一篇

溴丙烯在800 nm和400 nm飞秒激光强场下的解离电离

刘洋, 刘博通, 杨岩, 孙真荣   

  1. 华东师范大学 精密光谱科学与技术国家重点实验室, 上海 200062
  • 收稿日期:2018-05-02 出版日期:2019-05-25 发布日期:2019-05-30
  • 通讯作者: 杨岩,男,工程师,研究方向为原子分子超快动力学.E-mail:yyang@lps.ecnu.edu.cn. E-mail:yyang@lps.ecnu.edu.cn
  • 作者简介:刘洋,女,硕士研究生,研究方向为原子分子超快动力学.E-mail:1156014088@qq.com.
  • 基金资助:
    国家自然科学基金(11474096,11727810)

Dissociative ionization of allyl bromide in 800 nm and 400 nm intense femtosecond laser fields

LIU Yang, LIU Bo-tong, YANG Yan, SUN Zhen-rong   

  1. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
  • Received:2018-05-02 Online:2019-05-25 Published:2019-05-30

摘要: 利用自行搭建的飞行时间质谱仪,在800 nm和400nm飞秒激光强场下对溴丙烯分子进行了电离解离过程的探究.通过分析离子产物的产率与激光功率的依赖关系并结合Keldysh因子计算,给出了实验中母体分子的电离机制;理论上,利用量子化学计算软件(Gaussian 09),对分子的化学键柔性力常数、反应通道出现势进行了计算,确认了溴丙烯分子的电离解离通道,发现了非共振多光子吸收导致的多个化学键的同时断裂,解释了母体分子离子电荷布局对反应路径的影响.

关键词: 飞秒激光, 多光子电离解离, 飞行时间质谱, 量化计算

Abstract: Using a homemade time-of-flight mass spectrometer, the ionization and dissociation of gaseous molecular allyl bromide in 800 nm and 400 nm femtosecond laser fields were studied. By analyzing the dependence of ion fragment yields and laser intensity, combined with calculation of the Keldysh parameter, it was shown that multi-photon ionization dominates the ionization process involved in our experiment. Based on a theoretical calculation with the Gaussian 09 software package, flexible force constants and appearance energies of different fragment ions were calculated and dissociation channels were identified. Meanwhile, the results demonstrate that non-resonant multi-photon absorption will lead to simultaneous cleavage of multi-chemical bonds; moreover, the charge distribution of parent ions will steer the reaction pathway.

Key words: femtosecond laser, multiphoton dissociative ionization (MPDI), time-offlight mass spectrometry (TOF-MS), quantum chemistry calculation

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