Molecular Species Ejected on Warming of Irradiated Carbon and Sulfur Containing

We have irradiated samples of CH sub 4, CO sub 2, CS sub 2, H sub 2 S and ice mixtures by MeV and keV ions. These ions produce direct sputter ejection and, on warming, produce new molecular species. These processes simulated the erosion of ejected materials by the local comet plasma and also long term modification of the ices prior to approach to the sun. Mass spectra analysis has been carried out for the ejected molecules and these spectra are relevant for interpreting the near nucleus molecular composition of the corona. In this paper we review the data and present new results.