Collisional removal of O2(b 1Σg+,v=1,2) by O2, N2, and CO2

Abstract

A state-specific two-laser technique is used to investigate the collisional removal of O 2 molecules in the b 1 ⌺ g ϩ (vϭ1,2) levels, where we directly excite O 2 and then probe the populations by resonance-enhanced multiphoton ionization. We find general agreement with earlier 300 K values for vϭ1 removal by O 2 , and show that vϭ2 removal is slower by a factor of 5.6Ϯ0.6 than vϭ1 removal. Only upper limits are obtained for N 2 as a collider. For removal of vϭ1 in the atmosphere, N 2 is unimportant compared to O 2 , but it might be competitive for vϭ2. For CO 2 as a collider, addressing O 2 (b 1 ⌺ g ϩ ) removal in the atmospheres of Mars and Venus, the removal rate coefficients of the vibrationally-excited levels are similar to that for vϭ0. The significance of the large difference in the vϭ1 and vϭ2 rate coefficients for O 2 collisions will be discussed as it relates to the modeling of recent earth nightglow observations.

The study of intermolecular energy transfers in electronic energy quenching for molecular collisions N<sub>2</sub>-N<sub>2</sub>, N<sub>2</sub>-O<sub>2</sub>, O<sub>2</sub>-O<sub>2</sub>

“…The results of our calculation for vibrational levels v=1-25 of the a 1 g state and v=1-20 of the b 1 + g state at temperatures of 155 and 300 K are compared in Figs. 10 and 11 with the experimental data by Hwang et al (1998), Bloemink et al (1998, Kalogerakis et al (2002), Slanger and Copeland (2003) obtained at room temperature and the experimental data by Amaral et al (2002), Slanger and Copeland (2003) obtained at a temperature of 155 K. It is seen from Figs. 10 and 11 that there is good agreement between the calculated rate coefficients and experimental data for low and high vibrational levels for both states.…”

Review of tropical nightglow studies with astronomical instruments

“…Monthly Notices of the Royal Astronomical Society 124, 505-522. Kalogerakis, K.S., Totth, A., Cosby, P.C., Slanger, T.G., Copeland, R.A., 1998. Laboratory studies of the production of highly vibrationally excited O 2 (a 1 D g ,b 1 S g + ) from O 2 (A 3 S u +…”

“…Simultaneously, SRI researchers have evaluated the O 2 and N 2 collisional relaxation rates both for the lower b 1 S g + levels, v ¼ 1-3 (Bloemink et al, 1998;Hwang et al, 1999;Kalogerakis et al, 2002), and for high levels, v ¼ 11-15 (Kalogerakis et al, 2001). The former are produced by direct laser excitation of O 2 , whereas the latter come from collisional relaxation of laser-excited O 2 (A 3 S u + ) in v ¼ 6-10.…”

Electronically excited molecular nitrogen and molecular oxygen in the high-latitude upper atmosphere

“…Rate coefficients for the quenching by N 2 and O were measured by Bloemink et al (1998), Kalogerakis et al (2002Kalogerakis et al ( , 2004. The results of their measurements are sometimes uncertain and limited to separate vibrational levels of the state.…”