| Abstract
| - The relative quantum yield for the production of radical products, H and HCO, from the photolysis offormaldehyde (HCHO) has been measured directly at wavelengths from 269 to 339 nm. Measurements of theradical products were conducted using chemical amplification with subsequent detection by chemical ionizationmass spectrometry (CIMS). All yields were measured at a pressure of 50 Torr and were normalized to aquantum yield of 0.753 at 303.75 nm based on the recommendation of DeMore et al. The quantum yieldswere measured with sufficient wavelength resolution (± 0.62 nm, fwhm) to observe structure which hadbeen previously unreported and is believed to provide evidence for a complicated competition among thevarious dissociation pathways to H + HCO, H + H + CO and H2 + CO, as well as with quenching to theground state. The quantum yields measured should aid in the calculation of formaldehyde photolysis rates inthe troposphere and are estimated to result in increases of at least 8% in calculated H/HCO production.
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