Excitation of the O/sub 2/(a /sup 1/. delta. /sub g/) state by low energy electrons in O/sub 2/--N/sub 2/ mixtures

Journal Article · Mon Mar 14 23:00:00 EST 1983 · J. Chem. Phys.; (United States)

OSTI ID:5636610

Yamabe, C; Phelps, A V

Coefficients for the excitation of the a /sup 1/..delta../sub g/ state of O/sub 2/ by low energy electrons in mixtures of O/sub 2/--N/sub 2/--Ar and O/sub 2/--N/sub 2/ and in pure O/sub 2/ have been determined using a drift tube technique. The time dependence of the absolute intensity of 1.27 ..mu..m band emission was measured for 1% to 5% O/sub 2/ and 1% to 10% N/sub 2/ in Ar at total gas densities of 2 to 10 x 10/sup 24/ m/sup -3/ and in 20% O/sub 2/--80% N/sub 2/ mixtures at a total density of about 2 x 10/sup 24/ m/sup -3/. The measured decay constants for O/sub 2/(a /sup 1/..delta..) metastable densities in these mixtures are in agreement with previous data. Comparison of experimental and calculated excitation coefficients for the mixtures shows the importance of a /sup 1/..delta../sub g/ excitation by cascading from the states of the A /sup 3/..sigma../sup +//sub u/, C /sup 3/..delta../sub u/, and c /sup 1/..sigma../sup -//sub u/ group near 5 eV in O/sub 2/ for mean electron energies between 1.5 and 5 eV. Using published a /sup 1/..delta.. deexcitation rate coefficients, the measurements of absolute intensity at 1.27 ..mu..m from pure O/sub 2/ yield excitation coefficients that agree satisfactorily with theory at E/N values of 8--20 x 10/sup -21/ Vm/sup 2/.

• Research Organization: Joint Institute for Laboratory Astrophysics, University of Colorado and National Bureau of Standards, Boulder, Colorado 80309
• OSTI ID: 5636610
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:6; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
COLLISIONS
DISPERSIONS
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
EMISSION SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
GASES
MIXTURES
MOLECULE COLLISIONS
NITROGEN
NONMETALS
OXYGEN
RARE GASES
SPECTRA