Photoelectron imaging on vibrational excitation and Rydberg intermediate states in multi-photon ionization process of NH3 molecule

• 作者: Fu-Chun Liu Hai-Bin Du Jing Leng Lan-Lai He Le-Le Song Qin Yang Si-Zuo Luo Xiao-Chun Wang Ya-Nan Sun Yan-Hui Wang
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（9）
• 所属期刊栏目: ATOMIC AND MOLECULAR PHYSICS
• 页码范围: 304-311
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab9431

摘要

The ionization processes of NH3 molecule are studied by photoelectron velocity map imaging technique in a linearly polarized 400-nm femtosecond laser field.The two-dimensional photoelectron images from ammonia molecules under different laser intensities are obtained.In the slow electron region,the values of kinetic energy of photoelectrons corresponding to peaks 1,2,3,and 4 are 0.27,0.86,1.16,and 1.6 eV,respectively.With both the kinetic energy and angular distribution of photoelectrons from NH3 molecules,we can confirm that the two-photon excited intermediate Rydberg state is A～1 A″2 (v′2 =3) state for photoelectron peaks 2,3,4,and the three peaks are marked as 1223 (2+2),1123 (2+2),and 1023 (2 + 2) multi-photon processes,respectively.Then,peak 1 is found by adding a hexapole between the source chamber and the detection chamber to realize the rotational state selection and beam focusing.Peak 1 is labeled as the 1323 (3 + 1) multi-photon process through the intermediate Rydberg state E～ 1A′1.The phenomena of channel switching are found in the slow electron kinetic energy distributions.Our calculations and experimental results indicate that the stretching vibrational mode of ammonia molecules varies with channels,while the umbrella vibration does not.In addition,we consider and discuss the ac-Stark effect in a strong laser field.Peaks 5 and 6 are marked as (2 + 2 + 1) and (2 + 2 + 2) above threshold ionization processes in the fast electron region.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	Ya-Nan Sun		1	0	0.0	0.0
2	Yan-Hui Wang		1	0	0.0	0.0
3	Le-Le Song		1	0	0.0	0.0
4	Hai-Bin Du		1	0	0.0	0.0
5	Xiao-Chun Wang		1	0	0.0	0.0
6	Lan-Lai He		1	0	0.0	0.0
7	Si-Zuo Luo		1	0	0.0	0.0
8	Qin Yang		1	0	0.0	0.0
9	Jing Leng		1	0	0.0	0.0
10	Fu-Chun Liu		1	0	0.0	0.0