VISIBLE ABSORPTION CROSS-SECTIONS AND INTEGRATED ABSORPTION INTENSITIES OF MOLECULAR-OXYGEN (O-2 AND O-4)

Absorption spectra of gas-phase molecular oxygen and zero air at tempe ratures of 223 and 283 K have been measured in the laboratory using a coolable multipass-optics gas cell and Fourier transform spectroscopy in the wavelength range 455 to 830 nm (12,000-22,000 cm(-1)). Net abso rption cross sections of the O-2 A-, B-, and gamma-bands at <0.002 nm spectral resolution, and pressures of 100 and 1000 hPa zero air have b een determined. Binary absorption cross sections of the collision-indu ced O-4 bands at <0.18 nm spectral resolution and a pressure of 1000 h Pa pure oxygen have been determined, with corrections for the O-2 gamm a-band absorption. Calculated integrated absorption intensities and, f or the O-2 A- and B-bands, ''effective'' Einstein A-coefficients are c ompared with previous literature values.