1. STUDIES OF THE FORMATION OF CARBONYL SULFIDE IN ION-IRRADIATED ICES Robert F. Ferrante Morgan M. Spiliotis U.S. Naval Academy Marla H. Moore NASA/Goddard Space Flight Center Reggie L. Hudson Eckerd College 61 st International Symposium on Molecular Spectroscopy The Ohio State University June 2006

2. Ehrenfreund, P. and Fraser, H, “Ice Chemistry in Space”, Solid State Astronomy, NATO ASI Series, V. Pirronello and J. Krelowski, eds., Kluwer Academic Publ. (2002). ASTRONOMICAL OBSERVATIONS OF OCS

3. H + beam from vdG accelerator

11. RESULTS AND CONCLUSIONS OCS is readily formed by solid-state processes in low-temperature ices subjected to proton irradiation - additional thermal activation not required - H 2 S > SO 2 > CS 2 as sulfur source OCS is relatively unstable to destruction by irradiation - significantly more labile than other S species: OCS > H 2 S >> SO 2 > CS 2 - readily forms SO 2 and CS 2 on prolonged exposure OCS formation enhanced by thermal processing in some systems