Energetic ballistic deposition of volatile gases into ice

Gases are trapped in ice when they adsorb to the surface and are subsequently buried by further adsorption of water. Low surface temperatures, where the surface residence time of the gas is long, are needed to permit burial. Here, we demonstrate a new mechanism, energetic ballistic deposition, which has not been previously reported. Translationally energetic xenon atoms penetrate the ice surface and become stably embedded within the ice well above the xenon desorption temperature. This new mechanism for gaseous incorporation warrants consideration in models that seek to accurately describe the trapping and concentration of volatile gases in molecular solids. (C) 2012 Elsevier B.V. All rights reserved.