Sputter ejection of matter from Io

Alkali and Chlorine Photochemistry in a Volcanically Driven Atmosphere on Io

“…This "banana" cloud (also called the B cloud) is believed to result from low-speed (e.g., a few km s −1 ) ejection of Na from sputtering of Io's atmosphere or surface (e.g., Matson et al 1974, Haff et al 1981, Smyth and Combi 1988.…”

“…Observations taken over the past few decades indicate that the B cloud is remarkably stable over long time periods (see Schneider et al 1989, Thomas 1992, and references therein), although a long-term increase in the inferred Na supply rate of 0.18 × 10 26 atoms s −1 per year from 1990 to 1994 might be indicated from the data and modeling of Cremonese et al (1998), and variations of up to a factor of 2 were observed in the 1970s (Bergstrahl et al 1975). The ultimate source of the lowspeed sodium that populates the corona and B cloud is currently believed to be sputtering of atmospheric sodium by a cascade of ion-neutral and neutral-neutral collisions caused by the interaction of corotating torus ions with atmospheric constituents (e.g., Haff et al 1981, Smyth and Combi 1988). …”

Solar system sputtering

“…In addition, the motion of 10 relative to the torus gives a large flux of S (520 eV) and K atoms removed to maintain the present and 0 (260eV) ions; these ions will efficiently densities in the neutral clouds. 48 The calculations sputter the surface if the atmosphere is sufficiently also indicate an adequate flux of sputtered S and 0 thin, and will sputter material from the atmosphere to stabilize the torus, but the situation is somewhat in any c a~e .~8 If NazS and KzS are present at the uncertain because it is not clear how much frozen 1%…”

Plasma ion‐induced molecular ejection on the Galilean satellites: Energies of ejected molecules

“…That is, we ignore the temperature dependence of the sputtering yield and sublimation (particularly in the subsolar regions). Further, those molecules which escape have not been included (Watson, 1981). More importantly, unit sticking probability has been assumed.…”

“…Laboratory measurements of the charged-particle erosion of these surface materials have been combined with satellite-measured incident particle fluxes to compare the rates of the sputter ejection of molecules with the rates of ordinary sublimation. The results have then been used to estimate the net loss of surface material to space, 'atmospheric' column densities for the ejected molecules, the erosion of surface features, and the net redistribution of volatile material across the satellite surfaces (Lanzerotti, et al, 1978' Haft et al, 1979' Johnson et al, 1981Watson, 1981;Brown et al, 1982b;Sieveka and Johnson, 1982). These past estimates required assumptions about the energy and mass distributions of the ejected molecular species.…”