Sputtering of Ices

摘要: Data obtained from the exploration of outer solar system has led to a new area physics: electronically induced sputtering low-temperature, condensed-gas solids, here referred as ices. Icy bodies in are bombarded by relatively intense fluxes ions and electrons, well background UV flux, causing changes their optical reflectance ejection (sputtering/desorption) molecules surfaces. The low cohesive energies ices lead large rates both momentum transfer (‘knock-on’ collisions) electronic excitations produced incident particles. Such produces an ambient gas about icy body, often source local plasma. This chapter focuses on material ionizing radiation surface that is predominantly molecular condensed solid. types considered photons, electrons with emphasis processes. also chemical effects described chapters sections II III. induced-chemistry can produce more refractory volatile products so affect rate. this production gas-phase species surfaces space. We describe physics chemistry leading atoms molecules, give semi-empirical expressions based these processes, some applications.