Velocity map imaging study of OCS photodissociation followed by S(1S) autoionization at 157nm
| Autor: | Shiou-Min Wu, David H. Parker, Xueming Yang |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Chemistry
Photodissociation Biophysics Condensed Matter Physics Laser Ion law.invention Autoionization law Excited state Ionization Atom Physics::Atomic and Molecular Clusters Molecular and Laser Physics Physics::Atomic Physics Physics::Chemical Physics Physical and Theoretical Chemistry Atomic physics Molecular Biology Molecular beam |
| Zdroj: | Molecular Physics, 103, 1797-1807 Molecular Physics, 103, 13, pp. 1797-1807 |
| ISSN: | 0026-8976 |
| DOI: | 10.1080/00268970500054714 |
| Popis: | Atomic sulphur ions (S+) were observed directly by crossing a carbonyl sulphide (OCS) molecular beam with a F2 laser. In this study both S+ ion and electron images were measured using the velocity map imaging technique. The results imply that S+ is produced from the well-known photodissociation of OCS at 157 nm leading to the dominant S(1S) + CO(1Σ+) channel, and then the excited S(1S) atom is directly ionized by another 157 nm photon. Correlated vibrationally resolved angular distributions and internal energy distribution of the CO coproducts are reported here and compared with previous studies. This experiment yields strong and sharp S+ images which may be useful for calibrating any imaging or laser ionization apparatus when using a 157 nm laser. A number of technical aspects such as corrections for partial slicing and imperfect laser polarization are described. Abstraction of product angular distributions using both polarized and unpolarized photolysis lasers is also demonstrated using velocity map ima... |
| Databáze: | OpenAIRE |
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