PNNL

Abstract

Absorption cross sections have been measured at 5 temperatures between -60 and 50?C for the infrared bands of SF5CF3. The spectra were recorded mostly at 0.112 cm-1 resolution with a Fourier transform spectrometer and samples contained in a 19.95 cm temperature controlled cell. Individual samples were diluted with high purity nitrogen at 760 Torr to determine cross sections with 5 or more spectra analyzed at each temperature. The full spectral range of the measurements is 520 to 6500 cm-1. Spectra located in the 8-12 ?m window region important for climate change show a series of absorption bands with integrated absorption cross sections that closely match the integrated intensities and locations reported previously at room temperature. Only minor changes in the integrated cross sections with temperature were found. The results confirm the importance of SF5CF3 for climate change on a per molecule basis. A single Doppler-limited spectrum recorded at room temperature shows no fine structure in the 9-15 mm absorption bands.