Dual-pump CARS of Air in a Heated Pressure Vessel up to 55 Bar and 1300 K

Dual-pump Coherent anti-Stokes Raman scattering (CARS) measurements have been performed in a heated pressure vessel at NASA Langley Research Center. Each measurement, consisting of 500 single shot spectra, was recorded at a fixed location in dry air at various pressures and temperatures, in a range of 0.03-55×10(exp 5) Pa and 300-1373 K, where the temperature was varied using an electric heater. The maximum output power of the electric heater limited the combinations of pressures and temperatures that could be obtained. Charts of CARS signal versus temperature (at constant pressure) and signal versus pressure (at constant temperature) are presented and fit with an empirical model to validate the range of capability of the dual-pump CARS technique; averaged spectra at different conditions of pressure and temperature are also shown.