Free-electron laser induced processes in thin molecular ice
Abstract
Intermolecular reactions in and on icy films on silicate and carbonaceous grains constitute a major route for the formation of new molecular constituents in interstellar molecular clouds. In more diffuse regions and in protoplanetary discs, energetic radiation can trigger reaction routes far from thermal equilibrium. As an analog of interstellar ice-covered dust grains, highly-oriented pyrolytic graphite (HOPG) covered with D2O, NO, and H atoms is irradiated by ultrashort XUV pulses and the desorbing ionic and neutral products are analysed. The yields of several products show a nonlinear intensity dependence and thus enable the elucidation of reaction dynamics by two-pulse correlated desorption.
- This article is part of the themed collection: Astrochemistry of Dust, Ice and Gas