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arXiv · 1506.09006

Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes

J. -Y. Chesnel·Z. Juhász·E. Lattouf·J. A. Tanis·B. A. Huber·E. Bene·S. T. S. Kovács·P. Herczku·A. Méry·J. -C. Poully·J. Rangama·B. Sulik
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Abstract

It is shown that negative ions are ejected from gas-phase water molecules when bombarded with positive ions at keV energies typical of solar-wind velocities. This finding is relevant for studies of planetary and cometary atmospheres, as well as for radiolysis and radiobiology. Emission of both H- and heavier (O- and OH-) anions, with a larger yield for H-, was observed in 6.6-keV 16O+ + H2O collisions. The ex-perimental setup allowed separate identification of anions formed in collisions with many-body dynamics from those created in hard, binary collisions. Most of the ani-ons are emitted with low kinetic energy due to many-body processes. Model calcu-lations show that both nucleus-nucleus interactions and electronic excitations con-tribute to the observed large anion emission yield.

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J. -Y. Chesnel, Z. Juhász, E. Lattouf, J. A. Tanis, B. A. Huber, E. Bene, S. T. S. Kovács, P. Herczku, A. Méry, J. -C. Poully, J. Rangama, B. Sulik. 2015-06-30. Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes. https://doi.org/10.1103/physreva.91.060701

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