Translational energy distribution and asymmetry parameter of the excited hydrogen atom produced in e-C/sub 2/H/sub 2/ collisions: Dissociation dynamics of acetylene

Journal Article · Fri Apr 01 00:00:00 EST 1988 · J. Chem. Phys.; (United States)

OSTI ID:5274618

Ogawa, T; Tomura, H; Nakashima, K; Kawazumi, H

Dissociative excitation of acetylene induced in e-C/sub 2/H/sub 2/ collisions was investigated by measuring the Doppler profile and its angular dependence from H*(n = 4) at a resolution of 0.0065 nm. The translational energy distribution and the angular difference Doppler profile were calculated. The Balmer line was unpolarized. There are three major dissociation processes for H*(n = 4) from C/sub 2/H/sub 2/;their threshold energies and translational energy distributions are (1) 20.8, 0--2 eV, (2) )similarreverse arrowto)30, 3--5 eV, and (3) 35--40, 6--8 eV, respectively. Component 1 showed a clear anisotropy: the asymmetry parameter b is 0.5 +- 0.1 and the anisotropy of atomic emission J/sub p/ is 0. Thus, component 1 should be produced by predissociation through Rydberg states converging to the (2..sigma../sub u/)/sup -1/ state. The decrease of b from the theoretical maximum is due to arbitrary direction of the momentum transfer vector and a relatively long lifetime of the intermediate excited states. Components 2 and 3 are also anisotropic and b>0

• Research Organization: Department of Molecular Science and Technology, Kyushu University, Kasuga-shi, Fukuoka 816, Japan
• OSTI ID: 5274618
• Journal Information: J. Chem. Phys.; (United States), Vol. 88:7
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
ELECTRON-MOLECULE COLLISIONS
DISSOCIATION
HYDROGEN
EMISSION SPECTRA
EXCITED STATES
BALMER LINES
LIFETIME
MOMENTUM TRANSFER
RYDBERG STATES
ALKYNES
COLLISIONS
ELECTRON COLLISIONS
ELEMENTS
ENERGY LEVELS
HYDROCARBONS
MOLECULE COLLISIONS
NONMETALS
ORGANIC COMPOUNDS
SPECTRA
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena