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arXiv · 2001.07095

Desorption of neutrals, cations and anions from core-excited amorphous solid water

R. Dupuy·G. Féraud·M Bertin·C. Romanzin·L. Philippe·T. Putaud·X. Michaut·R. Cimino·V. Baglin·J. -H. Fillion
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Abstract

Core-excitation of water ice releases many different molecules and ions in the gas phase. Studying these desorbed species and the underlying mechanisms can provide useful information on the effects of X-ray irradiation in ice. We report a detailed study of the X-ray induced desorption of a number of neutral, cationic and anionic species from amorphous solid water. We discuss the desorption mechanisms, and the relative contributions of Auger and secondary electrons (X-ray induced Electron Stimulated Desorption) and initial excitation (\rev{direct desorption}) as well as the role of photochemistry. Anions are shown to desorb not just through processes linked with secondary electrons but also through direct dissociation of the core-excited molecule. The desorption spectra of oxygen ions (O$^+$, OH$^+$, H$_2$O$^+$, O$^-$, OH$^-$) give a new perspective on their previously reported very low desorption yields for most types of irradiation of water, showing that they mostly originate from the dissociation of photoproducts such as H$_2$O$_2$.

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R. Dupuy, G. Féraud, M Bertin, C. Romanzin, L. Philippe, T. Putaud, X. Michaut, R. Cimino, V. Baglin, J. -H. Fillion. 2020-01-20. Desorption of neutrals, cations and anions from core-excited amorphous solid water. https://doi.org/10.1063/1.5133156

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