Monitoring of the lifetimes of the metastable states in Au in an air-acetylene flame as a probe for local stoichiometric conditions by the laser-enhanced ionization technique
| Autor: | Ove Axner, Peter Ljungberg, Y. Malmsten |
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| Rok vydání: | 1993 |
| Předmět: |
Quenching
Materials science Physics and Astronomy (miscellaneous) General Engineering Analytical chemistry General Physics and Astronomy chemistry.chemical_element Partial pressure Photoionization Oxygen chemistry.chemical_compound chemistry Acetylene Metastability Ionization Atomic physics Stoichiometry |
| Zdroj: | Applied Physics B Photophysics and Laser Chemistry. 56:355-362 |
| ISSN: | 1432-0649 0721-7269 |
| Popis: | The behaviour of the lifetimes of the metastable 5d9 6s22D3/2 and 5d9 6s22D5/2 states in Au in an air/acetylene flame has been studied using the step-wise delayed laser-enhanced ionization technique. Using a new, fast and reliable, automated experimental procedure, we have conducted a systematic investigation of the lifetimes for various flame characteristics, namely lateral and vertical position in the flame and flame composition. It was found that the lifetimes of the metastable states are affected by at least three different mechanisms: i) a rather small but almost constant quenching rate, unaffected by the variations in the flame environment; ii) quenching by oxygen, which is proportional to the local partial pressure of oxygen; and iii) quenching by unburned fuel components. We have shown that by monitoring the lifetime of a metastable state as a function of various flame parameters, the conditions for local stoichiometry in the flame can be determined by this technique. |
| Databáze: | OpenAIRE |
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