Gas cell based on optical contacting for fundamental spectroscopy studies with initial reference absorption spectrum of H2O vapor at 1723 K and 0.0235 bar

- Design of a high temperature gas cell for spectroscopic studies is presented.
- An H2O vapor absorption spectrum measured in the cell at 1723 K is presented.
- Initial measurements demonstrate cell value for database improvement.

A gas cell, using optically contacted sapphire windows to form a hot vapor seal, has been created for high temperature fundamental spectroscopy studies. It is designed to operate at temperatures from 280-2273 K and pressures from vacuum to 1.3 bar. Using the cell in conjunction with an external cavity diode laser spectrometer, a reference H2O vapor absorption spectrum at P=0.0235±0.0036 bar and T=1723±6 K was measured with 0.0001 cm−1 resolution over the 7326-7598 cm−1 range. Comparison of the measured spectrum to simulations reveals errors in both the HITEMP and BT2 databases. This work establishes heated static cell capabilities at temperatures well above the typical limit of approximately 1300 K set by quartz material properties. This paper addresses the design of the cell as well as the cell׳s limitations.