Channel competition in dissociation of ammonia clusters(n≤5)induced by femtosecond laser fields  

作　　者：Tao Yang Xinyu Zhang Xing Li Wankai Li Menghao Wei Dongdong Zhang Lanhai He Dajun Ding 杨涛;张馨予;李兴;李万凯;卫孟昊;张栋栋;赫兰海;丁大军

机构地区：[1]Institute of Atomic and Molecular Physics,Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy,Jilin University,Changchun 130012,China [2]Basic Courses Department,Tianjin Sino-German University of Applied Sciences,Tianjin 300350,China [3]Institute of Atom Manufacturing,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Physics B》2025年第3期355-359,共5页中国物理B(英文版)

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.92261201,12134005,12334011)。

摘　　要：We investigated the ionization and dissociation processes of ammonia clusters ranging from dimer to pentamer induced by 800-nm femtosecond laser fields.Time-of-flight(TOF)mass spectra of the ammonia clusters were recorded over a range of laser intensities from 2.1×10^(12)W/cm^(2) to 5.6×10^(12)W/cm^(2).The protonated ion signals dominate the spectra,which is consistent with the stability of the geometric structures.The ionization and dissociation channels of ammonia clusters are discussed.The competition and switching among observed dissociation channels are revealed by analyzing the variations in the relative ionic yields of specific protonated and unprotonated clusters under different laser intensities.These results indicate that the ionization of the neutral multiple-ammonia units,produced through the dissociation of cluster ions,may start to contribute,as well as the additional processes to consume protonated ions and/or produce unprotonated ions induced by the femtosecond laser fields when the laser intensity is above^4×10^(12)W/cm^(2).These findings provide deeper insights into the ionization and dissociation dynamics in multi-photon ionization experiments involving ammonia clusters.

关 键 词：ammonia cluster ionization and dissociation femtosecond laser 

分 类 号：TN2[电子电信—物理电子学]