OCS分子紫外多光子电离和解离过程

A Study on Multiphoton Ionization-Dissociation of OCS Molecule using Time-of-Flight Mass Spectrometry

本文用多光子电离飞行时间质谱法分别测定了OCS分子在不同紫外激光波长和激光功率下的共振和非共振多光子电离和解离产物,结果表明其主要的正离子产物为OCS^+、S^+、CO^+和C^+离子.本文还对不同离子的产生机理分别作了讨论.

Multiphoton ionization-dissociation process of OCS molecules is studied using (?)-of-flight mass spectrometer with apulsed ultraviolet laser. Four ion peaks assigned to OCS+ , S', CO+ and C+ are observed under 278.5nm(I^1Π-X^1Σ^+ (000-000)), 280.0nm(F^1Π-X^1Σ^+)) and 281.1nm laser irradiation with different laser power. According to the experimental results, the multiphoton ionization-dissociation machanism of OCS molecule at those wavelengths are proposed as follow: First, OCS molecule is ionized to generate OCS^+ via (2+1) photon (two photon resonant excitation and one photon ionization) process at 278.5nm and 280.0nm as well as 3 photon nonresonant ionization process at 281.1nm respectively. Then, OCS^+ can absorb one more photon and dissociate to produce S^+ and CO. In addition, CO^+ and C^+ might be generated from multiphoton ionization-dissociation of CO molecules.