Study of the symmetric charge transfer reaction H/sup +//sub 2/+H/sub 2/ using the high resolution photoionization and crossed ion--neutral beam methods

Journal Article · Sat Dec 15 00:00:00 EST 1984 · J. Chem. Phys.; (United States)

OSTI ID:6212822

Liao, C; Liao, C; Ng, C Y

A new ion--molecule reaction apparatus, which combines the crossed ion--neutral beam method, high resolution photoionization mass spectrometry, and charge transfer detection, has been developed. Using this apparatus, we have examined the relative total charge transfer cross sections of H/sup +//sub 2/+H/sub 2/ as a function of the vibrational state of H/sup +//sub 2/, v/sup prime//sub 0/ = 0--4, at the center-of-mass collision energy (E/sub c.m./) range of 0.38--200 eV. The relative total charge transfer cross sections measured at E/sub c.m./ = 8, 16, 22.5, and 200 eV are in general agreement with a recent theoretical calculation based on the semiclassical energy conserving trajectory formulation. The vibrational energy effects on the cross sections for the charge transfer and the H/sup +//sub 3/+H channels at low collision energies (E/sub c.m./ < or =1 eV) were directly observed. The rotational states, J = 0, 1, and 2, of H/sup +//sub 2/(v/sup //sub 0/ = 0) were also selected in this experiment. Within experimental uncertainties, the rotational excitations of H/sup +//sub 2/(v/sup prime//sub 0/ = 0) have no effect on the relative total charge transfer cross sections at E/sub c.m./ = 2 and 4 eV. By calibrating the nominal relative total charge transfer cross sections obtained with an ionizing photon energy of 18 eV (688 A) to absolute total charge transfer cross sections determined previously using low energy electron impact ionization, absolute total charge transfer cross sections for v/sup //sub 0/ = 0 and 1 in the kinetic energy range of E/sub c.m./ = 8--200 eV were estimated. The absolute total charge transfer cross sections thus obtained for v/sup prime//sub 0/ = 0 and 1 are lower than the theoretical values by approximately a factor of 2.

• Research Organization: Ames Laboratory, U. S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6212822
• Journal Information: J. Chem. Phys.; (United States), Vol. 81:12
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
ION-MOLECULE COLLISIONS
HYDROGEN IONS 1 PLUS
CHARGE EXCHANGE
CHEMICAL REACTIONS
ION BEAMS
MASS SPECTROSCOPY
MOLECULAR BEAMS
MOLECULAR IONS
PHOTOIONIZATION
BEAMS
CATIONS
CHARGED PARTICLES
COLLISIONS
ELEMENTS
HYDROGEN IONS
ION COLLISIONS
IONIZATION
IONS
MOLECULE COLLISIONS
NONMETALS
SPECTROSCOPY
640304* - Atomic
Molecular &amp; Chemical Physics- Collision Phenomena