Vibrationally resolved inelastic and charge transfer scattering of H/sup +/ by H/sub 2/O

Journal Article · Sun Nov 01 04:00:00 EST 1987 · J. Chem. Phys.; (United States)

OSTI ID:6117379

Friedrich, B; Niedner, G; Noll, M; Toennies, J P

Inelastic and charge transfer scattering of protons by water molecules at collision energies of 27.0 and 46.0 eV have been investigated in a high-resolution crossed beam experiment up to the rainbow scattering angles. Excitation of the stretching (symmetric or asymmetric) and bending mode vibrations within the electronic ground state, X /sup 1/A/sub 1/, of H/sub 2/O was observed in the proton energy-loss spectra. In the case of charge transfer, formation of H/sub 2/O/sup +/ in the X /sup 2/B/sub 1/ and A-italic-tilde /sup 2/A/sub 1/ electronic states was identified in the corresponding H-atom spectra; the vibrational states within the X and A-italic-tilde bands were for the most part resolved and, at small angles (thetaless than or equal to2/sup 0/), they were found to be nearly the same as in photoionization (symmetric stretch and bending mode excitation within the X state and pure bending mode excitation within the A-italic-tilde state). The vibronic transition probabilities deviate, however, considerably from the corresponding Franck--Condon factors in favor of the enhancement of the quasiresonant states. For both the inelastic and charge transfer scattering, state-selected quantities characteristic of the detailed collision dynamics have been derived. In addition, rotational excitation superimposed on the vibrational transitions could be estimated and for both processes it was found to be of the order of 50--100 meV.

• Research Organization: Max-Planck-Institut fuer Stroemungsforschung, D-3400 Goettingen, Federal Republic of Germany
• OSTI ID: 6117379
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 87:9; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
BEAMS
CATIONS
CHARGE EXCHANGE
CHARGED PARTICLES
COLLISIONS
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EV RANGE 10-100
EXCITATION
EXCITED STATES
FLUIDS
GASES
HYDROGEN IONS
HYDROGEN IONS 1 PLUS
ION BEAMS
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONS
MOLECULE COLLISIONS
VAPORS
VIBRATIONAL STATES
WATER VAPOR