Branch intensities and oscillator strengths for the Herzberg absorption systems in oxygen

Abstract

We report two complementary experimental investigations of the absorption spectrum of molecular oxygen between 243 and 258 nm. In the first experiment, excitation of O2 is inferred by detecting oxygen atoms resulting from chemical reaction. In the second experiment, absorption by O2 is observed directly by cavity ring-down spectroscopy. Absorption strengths for the Herzberg I [Formula: see text], Herzberg II [Formula: see text], and Herzberg III [Formula: see text] band systems are modeled with the DIATOM spectral simulation computer program using the best available branch intensity formulas. Absolute oscillator strengths are derived for all three systems and compared with values in the literature.

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

“…For the A-X transition, they are in good agreement with those of previous works [12][13][14][15][16], but significant discrepancies with older literature data are found for the c-X and A'-X systems.…”

Fourier Transform Spectroscopy of the O2 Herzberg Bands

“…The values for the integrated cross sections and band oscillator strengths of the c-X transition are given in Table 2b. Comparisons are made with the recommended values of Huestis et al (7) and with the more recent values of Yoshino et al (21). The values derived from Bates (18) (not included in Table 2b) are three to four times larger.…”

“…figure presents the values of the integrated cross sections for the lines previously assigned (1,5,7,9) …”

“…Previous, high-resolution recordings by photographic (4 -6) and photoelectric (7)(8)(9)(10) techniques have allowed the extension of the vibrational and rotational assignments given by Herzberg (1,2) in the three transitions and the improvement of the molecular parameters of the upper states. We have reported in a recent paper (13), hereafter referred to as Paper I, the observation and the assignments of new lines, particularly in the AЈ-X transition and given new information on the c-A interactions.…”

“…Later, modern techniques such as cavity ring-down spectroscopy (CRDS) and Fourier transform spectroscopy (FTS) allowed the reinvestigation of the intensities in the A-X bands (7, 8, 10, 16 -20). Four (7,18,21,22) and three (7,18,23) studies also report on the intensities of the c-X and AЈ-X transitions, respectively; two of them (18,23) are theoretical papers.…”