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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

Journal Article · · Physical Review A; (United States)
; ;  [1]
  1. 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