Near-UV photolysis cross sections of CH<sub>3</sub>OOH and HOCH<sub>2</sub>OOH determined via action spectroscopy
Knowledge of molecular photolysis cross sections is important for determining atmospheric lifetimes and fates of many species. A method and laser apparatus for measurement of these cross sections in the near-ultraviolet (UV) region is described. The technique is based on action spectroscopy, where t...
| Published in: | Atmospheric Chemistry and Physics |
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| Main Authors: | , , , |
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2007-01-01
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| Online Access: | http://www.atmos-chem-phys.net/7/713/2007/acp-7-713-2007.pdf |
| Summary: | Knowledge of molecular photolysis cross sections is important for determining atmospheric lifetimes and fates of many species. A method and laser apparatus for measurement of these cross sections in the near-ultraviolet (UV) region is described. The technique is based on action spectroscopy, where the yield of a photodissociation product (in this case OH) is measured as a function of excitation energy. For compounds yielding OH, this method can be used to measure near-UV photodissociation cross section as low as 10<sup>−23</sup> cm<sup>2</sup> molecule<sup>−1</sup>. The method is applied to determine the photodissociation cross sections for methyl hydroperoxide (CH<sub>3</sub>OOH; MHP) and hydroxymethyl hydroperoxide (HOCH<sub>2</sub>OOH; HMHP) in the 305–365 nm wavelength range. The measured cross sections are in good agreement with previous measurements of absorption cross sections. |
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| ISSN: | 1680-7316 1680-7324 |