Knowledge Bank

Cross sections of $O2$ at 300 K have been obtained from photoabsorption measurements at various pressures throughout the wavelength region 179.3-201.5 nm with a 6.65 m photoelectric scanning spectrometer equipped with a 2400 line/nm grating and having an instrumental width (PWHM) of 0.0013 nm. The measured absorption cross sections of the Schumann-Runge bands (12,0) through (1,0) in this wavelength region are absolute, i.e., independent of the instrumental width, a result not achieved previously. The measured cross sections will be presented graphically. Band oscillator strengths of the (12,0) through (1,0) bands have been determined by direct numerical integration of the measured cross sections. Preliminary results of cross sections at 77 K will be discussed. This work is supported by NASA Grant NSG 5176 to Harvard college.