Photodissociation Photoexcitation and Dissociation Probabilities for the Sulfur Isotopologues of SO2 SO and CS2 and Application to Sulfur MIF

Photodissociation Photoexcitation and Dissociation Probabilities for the Sulfur Isotopologues of SO2 SO and CS2 and Application to Sulfur MIF Photodissociation, photoexcitation, and dissociation probabilities for the sulfur isotopologues of SO2, SO, and CS2, and application to sulfur MIF The objective of this proposal is to identify the chemical mechanism responsible for the mass-independent fractionation of sulfur isotopes seen in Archean sedimentary rocks. We propose to measure the following: 1) high-resolution photoexcitation cross sections of xSO2 ('x' indicates a sulfur isotope, either 32, 33, 34 or 36); 2) the dissociation probabilities for xSO2 from high resolution linewidth and fluorescence measurements; 3)the rates of collisional and radiative deactivation of excited-state xSO2 using fluorescence measurements; 4) the absorption cross sections of xSO; 5) the absorption cross sections for the sulfur isotopologues of CS2. The results of these measurements will be incorporated into photochemical model simulations of sulfur isotopes in the Archean atmosphere.