N_2O^+离子A^2Σ^+电子态的光谱研究  

The spectral assignment for the A^2Σ^+←X^2Π transition of N_2O^+ ions

作　　者：徐海峰[1] 郭颖[1] 李奇峰[1] 戴静华[1] 刘世林[1] 马兴孝[1] 梁军[2] 李海洋[2] 

机构地区：[1]中国科学院选键化学开放研究实验室,中国科学技术大学化学物理系,合肥230026 [2]中国科学院安徽光学精密机械研究所,合肥230031

出　　处：《物理学报》2004年第4期1027-1033,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展规划 (批准号 :G1 9990 7530 4 );国家自然科学基金(批准号 :2 0 2 730 6 3)资助的课题~~

摘　　要：用一束波长为 3 60 55nm的激光 ,通过N2 O分子的 (3 + 1)共振增强多光子电离过程制备纯净的母体离子N2 O+X2 Π3 2 ,1 2 (0 0 0 ) .用另一束可调谐激光将N2 O+ 离子激发至预解离态A2 Σ+ ,利用飞行时间质谱检测解离碎片NO+ 离子强度随光解光波长的变化 ,在 2 78— 3 2 8nm波长范围内获得了光解碎片的激发 (PHOFEX)谱 .观测到了N2 O+ 离子A2 Σ+ ←X2 Π电子跃迁较丰富的振动谱带 .通过对PHOFEX光谱的标识 ,获得了A2 Σ+The spectra of N 2O + ions in A 2Σ + state have been investigated. Pur e parent N 2O + ions, in the X 2Π 3/2,1/2 (000) state, were prepared by (3+1) multiphoton ionization of jet-cooled N 2O molecules using a laser be am at 360 55?nm. By introducing another laser, the pa rent ions were excited to the predissociative A 2Σ + state, an d the fragment NO + was detected by a time-of-flight mass spectrometer. The N O + photofragment excitation (PHOFEX) spectra were recorded by scanning the di ssociation laser in the wavelength range of 278—328?nm. The PHOFEX spectra cou ld be attributed completely to the A 2Σ +←X 2Π transition of N 2O +, in which most vibronic bands were observed for the first time. By considering t he Fermi resonance between the ν 1 and ν 2 modes, the spectra were assigned, and the spectral constants, such as vibrational frequencies, anharmon ic constants, and Fermi interaction constant, were obtained with relatively high r eliability and precision.

关 键 词：电子态 分子离子 分子物理学 光碎片激发谱 FERMI共振 光谱常数 大气电离层 光解波长 

分 类 号：O433[机械工程—光学工程]