New, optically forbidden Rydberg series in O/sub 2/ converging to the O/sup +//sub 2/ c /sup 4/S/sup -//sub u/ limit
We have measured the angular dependence of inelastically scattered electrons in O/sub 2/ in the energy-loss range 16 to 26 eV for incident electron energies between 75 and 400 eV, and for scattering angles between 2/sup 0/ and 12/sup 0/. For high incident energy and low scattering angle our energy loss spectra correspond to the known optical absorption spectrum. At higher scattering angles, four new structures appear in our spectra at 21.85, 23.30, 23.80, and 24.06 eV. These four structures are the lowest members of the first optically forbidden Rydberg series observed to converge to the O/sup +//sub 2/ c /sup 4/S/sup -//sub u/ limit at 24.56 eV. The calculated quantum defects for these levels are about 0.75. This value, combined with angular scattering propensity rules, indicates that the new Rydberg states occur by promotion of an electron from the s/sub u/2s orbital to nps/sub u/ orbitals, where n = 3,4,5,6. A consideration of the propensity rules for excitation of forbidden transitions by high energy electron impact suggest the term symbol of the new Rydberg states to be /sup 3/S/sup -//sub g/.
- Research Organization:
- Argonne National Laboratory, Argonne, Illinois 60439
- OSTI ID:
- 6352979
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 74:11; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
CHARGED PARTICLES
COLLISIONS
DISTRIBUTION
ELECTRON COLLISIONS
ELECTRON SPECTRA
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
ENERGY LOSSES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EV RANGE 10-100
EV RANGE 100-1000
FORBIDDEN TRANSITIONS
INELASTIC SCATTERING
IONS
LOSSES
MOLECULAR IONS
MOLECULE COLLISIONS
NONMETALS
OXYGEN
OXYGEN IONS
SCATTERING
SPECTRA