Ion-induced fragmentation of H2O molecules was investigated experimentally by 3He2+ impact as a function of the energy in the range from 1 to 5 keV, as well as a function of the charge state of 20 keV 20Neq+ projectiles (q ≤ 3 and 7). The fragments were detected in the angular range from 25° to 135° with respect to the incident beam direction. Particular emphasis is given to protons originating from collisions at large impact parameters involving a Coulomb explosion mechanism. Absolute cross sections dσ/dΩ, differential in the emission angle, are found to be anisotropic. Protons are preferentially emitted at angles near 90°, with cross sections being ∼50% larger than those at forward and backward angles. Possible mechanisms causing anisotropic emission of protons from fragmenting H2O are discussed.
|Number of pages||11|
|Journal||Journal of Physics B: Atomic, Molecular and Optical Physics|
|Publication status||Published - Feb 21 2006|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics