Absolute experimental differential and integral electron excitation cross sections for atomic oxygen 4. The (/sup 3/P-. -->. 3s'' /sup 3/P/sup 0/), (/sup 3/P. -->. 2s 2p/sup 5/ /sup 3/P/sup 0/), (/sup 3/P. -->. 4d' /sup 3/P/sup 0/) autoionizing transitions (878, 972, and 770
Absolute differential and integral direct electron excitation cross sections have been measured for the three most intense autoionizing /sup 3/P ..-->.. /sup 3/P/sup 0/ transitions in atomic oxygen (878, 792, and 770 A) and the first five members of the /sup 3/D/sup 0/ Rydberg series whose origin is the 1027 A transition. Incident electron energies from 30 to 200 eV were used. Absolute values of the differential cross sections were calculated using the previously measured atomic oxygen /sup 3/P ..-->.. /sup 3/S/sup 0/ (1304 A) cross sections were calculated using the previously measured atomic oxygen /sup 3/P ..-->.. /sup 3/S/sup 0/ (1304 A) cross section of Vaughan and Doering (1987) as a secondary standard. The cross sections were much more strongly forward peaked at the higher laboratory incident energies than at low energies. The integral cross sections for the 878- and 792 A transitions were identical within experimental error, both in shape and absolute magnitude. The peak values were 1.1--1.4 x 10/sup -17/ cm/sup 2/ at the maximum near 50 eV, about a factor of 3 lower than the total cross section deduced by Zipf and Kao (1986) from emission experiments. The 770 A transition was approximately a factor of 4 weaker with the same shape. The /sup 3/P/sup 0/ Rydberg series cross sections decrease uniformly with increasing principal quantum number as expected. The peak of the 1027 A origin transition is approximately 3.5 x 10/sup -18/ cm/sup 2/ at 50 eV, in satisfactory agreement with the emission cross section of Zipf and Erdman (1985).
- Research Organization:
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland
- OSTI ID:
- 5423617
- Journal Information:
- J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A1; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
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Absolute differential and integral electron excitation cross sections for atomic oxygen: 6. The /sup 3/P. -->. /sup 3/P and /sup 3/P. -->. /sup 5/P transitions from 13. 87 to 100 eV
Absolute experimental differential and integral electron excitation cross sections for atomic oxygen 1. The (/sup 3/P. -->. /sup 3/S/sup 0/) transition (1304 A) at 100 eV
Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
AUTOIONIZATION
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
DATA
DIFFERENTIAL CROSS SECTIONS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EV RANGE 10-100
EV RANGE 100-1000
EXCITATION
EXCITED STATES
EXPERIMENTAL DATA
INFORMATION
INTEGRAL CROSS SECTIONS
IONIC COMPOSITION
IONIZATION
IONS
NONMETALS
NUMERICAL DATA
OXYGEN
OXYGEN IONS
RADIATIONS
RYDBERG STATES
THERMOSPHERE
ULTRAVIOLET RADIATION