Fragmentation of water molecules in slow He2+ + H2O collisions

Przemyslaw Sobocinski (1) , Zoran D Pešić (1) , Rolf Hellhammer (1) , Nikolaus Stolterfoht (1) , Béla Sulik (2) , Sébastien Legendre (3) , Jean-Yves Chesnel (3)

1 Hahn-Meitner-Institut Berlin
2 ATOMKI - Institute for Nuclear Research [Budapest]
3 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique

The fragmentation in the collision system 3He2+ + H2O has been investigated experimentally at projectile energies ranging from 1 keV to 5 keV. The fragments were detected at angles from 25° to 130°. The experimental spectra exhibit two groups of peaks. The first one, which extends up to ~30 eV, is interpreted in terms of a Coulomb explosion mechanism. A second group observed at higher energies, corresponds to fragments and scattered projectiles produced in quasi-binary collisions. In the analysis, particular attention is paid to these energetic ions. Absolute cross sections dσ/dΩ, differential in the observation angle, are found to be in good agreement with calculations assuming that the interaction of the screened nuclei is described by the ZBL (Ziegler, Biersack and Littmark) potential.

Mots clés: Molecular fragmentation; Molecular dissociation; Molecular fragmentation dynamics; Fragment-energy distribution; Fragment-angular distribution; Electron capture; Ion-molecule collisions; Model calculations; Binary-encounter collisions; Elastic two-body collisions; Recoil ions; Scattering; Impact parameter; Coulomb explosion mechanism; ZBL potential

Domaines: Physique Atomique [physics.atom-ph]; Agrégats Moléculaires et Atomiques [physics.atm-clus]

Przemyslaw Sobocinski, Zoran D Pešić, Rolf Hellhammer, Nikolaus Stolterfoht, Béla Sulik, et al.. Fragmentation of water molecules in slow He2+ + H2O collisions. Journal of Physics B: Atomic, Molecular and Optical Physics, 2005, 38 (14), pp.2495. ⟨10.1088/0953-4075/38/14/013⟩. ⟨hal-01220149⟩