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| Titel |
O2(b1Σg+, v = 0, 1) Relative Yield in O(1D) + O2 Energy Transfer |
| VerfasserIn |
O. Kostko, S. Raj, K. M. Campbell, D. A. Pejakovic, T. G. Slanger, K. S. Kalogerakis |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060558
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| Zusammenfassung |
| Energy transfer from excited O(1D) atoms to ground-state O2(X3Σg-) leads to production
of O2 in the first two vibrational levels of the O2(b1Σg+) state: O(1D) + O2 - O(3P ) +
O2(b1Σg+, v = 0, 1). Subsequent radiative decay of O2(b1Σg+, v = 0, 1) to the ground state
results in the Atmospheric Band emission, a prominent feature of the terrestrial airglow. The
relative yield for production of O2(b1Σg+, v = 0, 1) in the above process, k1/k0, is an
important parameter in modeling of the observed O2 Atmospheric Band emission
intensities.
In the laboratory experiments, the output of a pulsed fluorine laser at 157 nm is used to
photodissociate molecular oxygen in an O2/N2 mixture flowing through a heated gas cell.
Photodissociation of O2 produces a ground-state O(3P ) atom and an excited O(1D) atom.
O(1D) rapidly transfers energy to the remaining O2 to produce O2(b1Σg+, v = 0, 1). The
populations of O2(b1Σg+, v = 0, 1) are monitored by observing emissions in the O2(b–X)
0–0 and 1–0 bands at 762 and 688 nm, respectively. The value of k1/k0 is extracted
from the time-dependent O2(b1Σg+, v = 0, 1) fluorescence signals using computer
simulations. We find that production of v = 1 is substantially larger than that of v =
0.
We will present measurements on k1/k0 and its temperature dependence, and discuss the
significance of these and other relevant laboratory measurements on the interpretation of the
O2 Atmospheric Band emission.
This work was supported by the US National Science Foundation (NSF) Aeronomy
Program under grant AGS-0937317. The fluorine laser was purchased under grant
ATM-0216583 from the NSF Major Research Instrumentation Program. The participation of
Sumana Raj and Kendrick M. Campbell was supported by a Research Experiences for
Undergraduates (REU) site, co-funded by the Division of Physics of the NSF and the
Department of Defense in partnership with the NSF REU program (PHY-1002892). |
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