Laser excitation of the A 3Σu+, A′3 Δu and c 1Σu− states of molecular oxygen

Studies on the production of O2(a1Δg, υ = 0) and O2(b1Σg+, υ = 0) from collisional removal of O2(A3Σu+, υ′ = 6–10)

“…In the case of O 2 ( b 1 Σ g + , υ = 0), nearly equal yields from O 2 and synthetic air are in contrast to the report by Wildt et al [1991]. They found that the addition of N 2 enhances the production of O 2 ( b 1 Σ g + , υ = 0) from collisional removal of O 2 ( A 3 Σ u + , υ ′ = 8), and concluded that the yield of O 2 ( b 1 Σ g + , υ = 0) from removal by N 2 is larger than the yield from removal by O 2 .…”

“…Collisional removal of O 2 ( A 3 Σ u + ) has been extensively investigated [ Copeland , 1994; Kenner and Ogryzlo , 1980, 1983, 1984; Knutsen et al , 1994; Slanger and Copeland , 2003; Wildt et al , 1991]. The room temperature removal rate coefficients for the υ ′ = 6−9 levels are greater than 10 −11 cm 3 s −1 for both O 2 and N 2 colliders (Table 2).…”

“…We refer to the O 2 ( a 1 Δ g , υ = 0) or O 2 ( b 1 Σ g + , υ = 0) yields to which our experiment is sensitive as the prompt yields. In this respect, our investigation of O 2 ( b 1 Σ g + , υ = 0) production differs from those of Shiau et al [1998], Bednarek et al [1994, 1997], and Wildt et al [1991], which were sensitive to yields at longer timescales (and were performed at room temperature). Delayed production of O 2 ( a 1 Δ g , υ = 0) and O 2 ( b 1 Σ g + , υ = 0) from O 2 ( A 3 Σ u + , υ ′) is possible via processes that may involve the formation of O 2 in high vibrational levels of the b 1 Σ g + , a 1 Δ g , and X 3 Σ g − states, followed by slower collisional processes.…”

“…In an effort to sort out possible sources of O 2 ( b 1 Σ g + , υ = 0) and O 2 ( a 1 Δ g , υ = 0), Wildt et al [1991] excited O 2 to the A 3 Σ u + , A ′ 3 Δ u , and c 1 Σ u − states by laser light in the wavelength region ∼248.8–250.0 nm, and for all three states observed emission in the b 1 Σ g + − X 3 Σ g − (0–0) band in the presence of O 2 collider. An important result of this study was that the spectrum obtained by scanning the excitation wavelength over the nearby A 3 Σ u + ← X 3 Σ g − , A ′ 3 Δ u ← X 3 Σ g − , and c 1 Σ u − ← X 3 Σ g − lines, while monitoring the b 1 Σ g + − X 3 Σ g − (0–0) emission, qualitatively resembled the O 2 absorption spectrum.…”

Nightglow vibrational distributions in the A<sup>3</sup>Σ<sub>u</sub><sup>+</sup> and A'<sup>3</sup>Δ<sub>u</sub> states of O<sub>2</sub> derived from astronomical sky spectra

“…Wildt et al (1991) have shown that when the higher levels of the A 3 + u state are excited, b 1 + g (v=0) is promptly formed upon O 2 collision (Wildt et al, 1991), and this observation has been confirmed (Shiau et al, 1998). It has also been shown by Ogryzlo et al (1984) that in a discharge flow with recombining O-atoms in N 2 , b 1 + g (v=0) emission is not seen until O 2 is added.…”