Helium broadened propane absorption cross sections in the far-IR

•High resolution absorption cross sections of propane (C3H8) in the far-IR (600-1200 cm−1).•Cross sections for pure and He broadened propane.•Measurements performed between 200-298 K.•Can be used for quantification of propane in giant planets.

Infrared absorption spectra for pure and He broadened propane have been recorded in the far-IR region (650-1300 cm−1) at the Canadian Light Source (CLS) facility using either the synchrotron or internal glowbar source depending on the required resolution. The measurements were made for 4 temperatures in the range 202-292 K and for 3 pressures of He broadening gas up to 100 Torr. Infrared absorption cross sections are derived from the spectra and the integrated cross sections are within 10 % of the corresponding values from the Pacific Northwest National Laboratory (PNNL) for all temperatures and pressures.