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Title: Absolute experimental differential and integral electron excitation cross sections for atomic oxygen. 3. The ( sup 3 P yields sup 3 D degree ) transition (989 angstrom ) from 20 to 200 eV with improved values for the ( sup 3 P yields sup 3 S degree ) transition (1,304 angstrom )

Abstract

The absolute differential and integral electron excitation cross sections for the atomic oxygen {sup 3}P {yields} {sup 3}D {degree} transition (989 {angstrom}) have been measured at incident energies from 20 to 200 eV. A variable angle and incident energy electron spectrometer coupled to a microwave discharge free supersonic jet expansion source was used for the experiments. The source produced an O/O{sub 2} density ratio typically greater than 2.5. The differential cross sections were determined by comparison to computer-fitted recalculations of the differential cross section for the atomic oxygen {sup 3}P {yields} {sup 3}S {degree} transition (1,304 {angstrom}). The method used for the computer fit and the results of the fitting calculations are discussed for the {sup 3}P {yields} {sup 3}S {degree} atomic oxygen transition (1,304 {angstrom}). The O I {sup 3}P {yields}{sup 3}S {degree} (989 {angstrom}) differential cross sections vary smoothly with the incident energy and are flatter with scattering angle at the lower incident energies, as expected. The absolute integral cross section is found to agree with the theoretical shape at higher energies. Previous estimates of this cross section from fluorescence data were larger than the present values by approximately a factor of 2. The present lower value appearsmore » to provide much better agreement with aurora and dayglow 989 {angstrom} emission intensities.« less

Authors:
;  [1]
  1. Johns Hopkins Univ., Baltimore, MD (United States)
Publication Date:
OSTI Identifier:
5398419
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research; (United States)
Additional Journal Information:
Journal Volume: 92:A7; Journal ID: ISSN 0148-0227
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AIRGLOW; EMISSION SPECTRA; AURORAE; ELECTRON-ATOM COLLISIONS; EXCITATION; OXYGEN; COMPARATIVE EVALUATIONS; DIFFERENTIAL CROSS SECTIONS; EV RANGE 10-100; EV RANGE 100-1000; INTEGRAL CROSS SECTIONS; ATOM COLLISIONS; COLLISIONS; CROSS SECTIONS; ELECTRON COLLISIONS; ELEMENTS; ENERGY RANGE; ENERGY-LEVEL TRANSITIONS; EV RANGE; EVALUATION; NONMETALS; SPECTRA; 661320* - Auroral, Ionospheric, & Magnetospheric Phenomena- (1992-)

Citation Formats

Vaughan, S O, and Doering, J P. Absolute experimental differential and integral electron excitation cross sections for atomic oxygen. 3. The ( sup 3 P yields sup 3 D degree ) transition (989 angstrom ) from 20 to 200 eV with improved values for the ( sup 3 P yields sup 3 S degree ) transition (1,304 angstrom ). United States: N. p., 1987. Web. doi:10.1029/JA092iA07p07749.
Vaughan, S O, & Doering, J P. Absolute experimental differential and integral electron excitation cross sections for atomic oxygen. 3. The ( sup 3 P yields sup 3 D degree ) transition (989 angstrom ) from 20 to 200 eV with improved values for the ( sup 3 P yields sup 3 S degree ) transition (1,304 angstrom ). United States. doi:10.1029/JA092iA07p07749.
Vaughan, S O, and Doering, J P. Wed . "Absolute experimental differential and integral electron excitation cross sections for atomic oxygen. 3. The ( sup 3 P yields sup 3 D degree ) transition (989 angstrom ) from 20 to 200 eV with improved values for the ( sup 3 P yields sup 3 S degree ) transition (1,304 angstrom )". United States. doi:10.1029/JA092iA07p07749.
@article{osti_5398419,
title = {Absolute experimental differential and integral electron excitation cross sections for atomic oxygen. 3. The ( sup 3 P yields sup 3 D degree ) transition (989 angstrom ) from 20 to 200 eV with improved values for the ( sup 3 P yields sup 3 S degree ) transition (1,304 angstrom )},
author = {Vaughan, S O and Doering, J P},
abstractNote = {The absolute differential and integral electron excitation cross sections for the atomic oxygen {sup 3}P {yields} {sup 3}D {degree} transition (989 {angstrom}) have been measured at incident energies from 20 to 200 eV. A variable angle and incident energy electron spectrometer coupled to a microwave discharge free supersonic jet expansion source was used for the experiments. The source produced an O/O{sub 2} density ratio typically greater than 2.5. The differential cross sections were determined by comparison to computer-fitted recalculations of the differential cross section for the atomic oxygen {sup 3}P {yields} {sup 3}S {degree} transition (1,304 {angstrom}). The method used for the computer fit and the results of the fitting calculations are discussed for the {sup 3}P {yields} {sup 3}S {degree} atomic oxygen transition (1,304 {angstrom}). The O I {sup 3}P {yields}{sup 3}S {degree} (989 {angstrom}) differential cross sections vary smoothly with the incident energy and are flatter with scattering angle at the lower incident energies, as expected. The absolute integral cross section is found to agree with the theoretical shape at higher energies. Previous estimates of this cross section from fluorescence data were larger than the present values by approximately a factor of 2. The present lower value appears to provide much better agreement with aurora and dayglow 989 {angstrom} emission intensities.},
doi = {10.1029/JA092iA07p07749},
journal = {Journal of Geophysical Research; (United States)},
issn = {0148-0227},
number = ,
volume = 92:A7,
place = {United States},
year = {1987},
month = {7}
}