HR: 0830h
AN: SA41A-13    [Abstracts]
TI: Measurement of Atomic and Molecular Parameters of Nitrogen for Earth, Planetary and Astrophysical Applications
AU: * Daw, A
EM: dawan@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Calamai, A
EM: calamaiag@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Brewer, S
EM: sb57037@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Estes, C
EM: ce48878@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Kanoy, J
EM: jk33794@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Myer, B
EM: bm53782@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AU: Stamilio, R
EM: rs36202@appstate.edu
AF: Appalachian State University, Dept. of Physics and Astronomy, CAP Building, Boone, NC 28608-2106 United States
AB: For the purpose of providing accurate atomic and molecular data for applications to the Earth's ionosphere and astrophysical plasmas, this project will provide measurements of: the radiative lifetime of the ⁵S metastable level of N⁺, the dissociation rate of doubly charged molecular nitrogen ions, electron capture rates from molecular nitrogen for both these ions, and the cross section for dissociative electron impact ionization of molecular nitrogen into metastable ⁵S N⁺, which is responsible for auroral 214 nm emission. Preliminary data and results are be presented. Ions are created in a radiofrequency ion trap by electron bombardment on nitrogen gas, and the UV radiation emitted by the stored ion population is then measured as a function of time. The primary source of radiation is the decaying metastable N⁺ ions, which emit photons at a wavelength of 214 nm. In addition to the atomic N⁺, doubly charged molecular ions (dications) are created and stored. Electron capture from neutral molecules into excited states of singly charged molecular nitrogen results in emission in bands that overlap with 214 nm. The decay rate of these two sources of radiation is measured as a function of nitrogen gas pressure to determine: the electron capture rates for both ions, the radiative decay rate of the metastable N⁺, and the dissociation rate of the dications. The photon observations are corrected for ion losses using the technique presented in Daw, Parkinson, Smith, & Calamai, ApJ 533, L179, 2000. Limits on the cross section for dissociative electron impact ionization of molecular nitrogen into metastable ⁵S N⁺ will be determined relative to the (well-known) cross section for dication production, by comparing the photon rate at 214 nm to the photon rate generated in different bandpasses as a result of dication electron capture.
DE: 0310 Airglow and aurora
DE: 2407 Auroral ionosphere (2704)
DE: 2423 Ionization mechanisms
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7549 Ultraviolet emissions
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly