Observation of CH [ital A] [sup 2][Delta][r arrow]X [sup 2][Pi][sub r] and [sup 2][Sigma][sup [minus]][r arrow]X [sup 2][Pi][sub r] emissions in gas-phase collisions of fast O([sup 3][ital P]) atoms with acetylene
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States) Phillips Laboratory/WSCI, 29 Randolph Road, Hanscom Air Force Base, Massachusetts 01731-3010 (United States)
Optical emissions in single-collision, beam-beam reactions of fast (3--22-eV translational energy) O([sup 3][ital P]) atoms with C[sub 2]H[sub 2] have been measured in the wavelength range 300--850 nm. Two features were observed, one with a peak wavelength at 431 nm, corresponding to the CH [ital A] [sup 2][Delta][r arrow]X [sup 2][Pi][sub r] transition, and a second weaker emission in the range 380--400 nm corresponding to the [ital B] [sup 2][Sigma][sup [minus]][r arrow]X [sup 2][Pi][sub r] transition. Both the [ital A][r arrow][ital X] and [ital B][r arrow][ital X] emissions were fit to a synthetic spectrum of CH([ital A]) at a vibrational temperature [ital T][sub [ital v]] of 10 000 K (0.86 eV) and a rotational temperature [ital T][sub [ital r]] of approximately 5000 K (0.43 eV); and CH([ital B]) to [ital T][sub [ital v]]=2500 K (0.22 eV) and [ital T][sub [ital r]]=1000 K (0.09 eV). The energy threshold for the [ital A][r arrow][ital X] emission was measured to be 7.3[plus minus]0.4 eV (lab) or 4.5[plus minus]0.2 eV (c.m.). This agrees with the energy threshold of 7.36 eV (lab) for the reaction O([sup 3][ital P])+C[sub 2]H[sub 2][r arrow]CH([ital A])+HCO.
- OSTI ID:
- 6450790
- Journal Information:
- Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 51:3; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
ALKYNES
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
BEAM DYNAMICS
BEAM-BEAM INTERACTIONS
BEAMS
COLLIDING BEAMS
COLLISIONS
DECAY
ELEMENTS
EMISSION SPECTRA
ENERGY
ENERGY LEVELS
ENERGY RANGE
EV RANGE
GROUND STATES
HYDROCARBONS
MOLECULE COLLISIONS
NONMETALS
ORGANIC COMPOUNDS
OXYGEN
PARTICLE DECAY
RADIATIVE DECAY
SPECTRA
THRESHOLD ENERGY