ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Dissociative excitation of acetylene induced in e-C2H2 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 C2H2; their threshold energies and translational energy distributions are (1) 20.8, 0–2 eV, (2) ∼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 Jp is 0. Thus, component 1 should be produced by predissociation through Rydberg states converging to the (2σu)−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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.453784
