HR: 0800h
AN: SA11A-0215    [Abstracts]
TI: O(¹D) Relaxation by O(³P)
AU: * Closser, K D
EM: kclosser@email.smith.edu
AF: SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States
AU: * Closser, K D
EM: kclosser@email.smith.edu
AF: Smith College, Department of Chemistry, Northampton, MA 01063 United States
AU: Pejaković, D A
EM: dusan.pejakovic@sri.com
AF: SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States
AU: Kalogerakis, K S
EM: ksk@sri.com
AF: SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States
AB: We report laboratory experiments investigating the relaxation of O(¹D) by O(³P) atoms. Rate coefficients for this process deduced from atmospheric observations and theoretical calculations have appeared in the literature that differ by more than an order of magnitude. No laboratory measurement of the rate coefficient is available, despite its importance in determining the energy flow in the upper atmosphere and controlling the intensity of atomic oxygen emissions. In the experiments, molecular oxygen is photodissociated to O(¹D) and O(³P) atoms by the 157-nm output of a fluorine laser. The temporal evolution of the O(¹D) concentration is monitored by detection of the 630-nm emission. Our laboratory results indicate that O(¹D) relaxation by O(³P) atoms is very efficient, with a rate coefficient of approximately 2 × 10^-11 cm³s^-1 at room temperature. The relevance to atmospheric observations and ionospheric heating experiments will be discussed. The participation of Kristina D. Closser was made possible by the NSF Research Experiences for Undergraduates Program under grant PHY-0353745. This research is supported by NSF grants ATM-0209229 and ATM-0216583.
DE: 0310 Airglow and aurora
DE: 0317 Chemical kinetic and photochemical properties
DE: 0358 Thermosphere: energy deposition (3369)
DE: 0394 Instruments and techniques
DE: 0399 General or miscellaneous
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005