Isotope separation of oxygen‐17, oxygen‐18, carbon‐13, and deuterium by ion laser induced formaldehyde photopredissociation

摘要: Near ultraviolet photopredissociation of formaldehyde has been verified as a highly selective method for enrichment the rare stable isotopes oxygen, hydrogen, and carbon contained in this molecule. High resolution absorption spectra rare‐isotope‐substituted fomaldehyde show coincidences to within Doppler profile with strong ion laser transitions Xeiii at 345 nm Neii 332 338 nm. By tuning each transition an intracavity etalon, optimum isotope was selected by monitoring fluorescence. Oxygen‐18 enriched up ninefold using natural neon lasing 332.374 nm, while substituting Ne‐22 permitted O‐17 33‐fold C‐13 332.371 Use D2CO instead H2CO 44‐fold O‐18 27‐fold enrichment. Hydrogen photoproducts showed 24‐fold HD 337.822 60‐fold 345.426 180‐fold D2 332.377 Single vibronic level photolysis HDCO shows greater than 90% molecular wavelengths longer 330 sudden rise 50% radical below 320 Photopredissociation yields less 1% photoproducts. Isotope scrambling is about 40% 325 but drops 6% 24% both Enrichment deuterium, carbon‐13, oxygen‐18 carried out initial composition ranging from abundance yield photoproduct 88% isotopic purity.