First experimental data of sulphur ions sputtering water ice

This paper presents the first experimental sputtering yields for sulphur ions with energies between 10 keV and 140 keV irradiating water ice films on a microbalance. The measured sputtering yields exceed theoretical predictions based on other ion species by a factor of 2 to 3 for most energies. Moreover, the sputtering yield of SF+ molecules is compared to the yield of atomic species S+ and F+. As found for atomic versus molecular oxygen, the sputtering yield caused by molecules is two times higher than expected. Finally, the implications of the enhanced sulphur sputtering yield for Europa’s atmosphere are discussed.