Absorptivity of Carbon Dioxide and Molecular Oxygen at 193 nm at High Temperatures up to 1600 °C

Abstract

The absorptivity of CO₂ and O₂ at 193 nm over the temperature range of 900–1600 °C is reported. The data were collected in a flow-type tube furnace using an ArF excimer laser at the light source. CO₂ was mixed at 5% by volume in N₂ and O₂ was examined at 5% and 10%. The internal transmittance of a 1-meter externally heated absorption cell was measured. The results establish a value for the absorptivity, α, for CO₂ ranging as high as 2.35 × 10⁻¹⁹ cm²/molecule at 1600 °C. For O₂, the absorptivity is 1.81 × 10⁻¹⁹ cm²/molecule at 1600 °C. The results partially agree with those reported in the literature recently by others at 1000 °C and 193 nm and extend those data to higher temperatures; however, the agreement is far from exact. The results are inconsistent with the higher temperature, 1500–2500 °C, values inferred by others from indirect measurements for these two species.