F. Amita et al., A high-temperature high-pressure optical cell for general-purpose spectrometers designed for supercritical water experiments, REV SCI INS, 72(9), 2001, pp. 3605-3609
We have developed a compact size high-temperature high-pressure optical cel
l that can be mounted on a commercially available general-purpose spectrome
ter. A small electric furnace heats the high-pressure optical cell while a
water-cooled thermal shielding jacket protects the spectrometer. This cooli
ng device works quite effectively to eliminate undesirable heating of spect
rometer optics and thus makes it possible to take spectra at temperatures u
p to 600 degreesC with an ordinary spectrometer. The optical cell is made o
f Hastelloy-X and equipped with two optical windows of synthetic sapphire.
The length and the diameter of the optical path are 10 and 6 mm, respective
ly. As the optical cell is combined with a flow system, which allows the qu
ick replacement of the sample solution with the reference water, the refere
nce signal can be taken immediately after the measurement of the sample sig
nal. The developed cell can be operated up to 60 MPa and 600 degreesC witho
ut any special modification to the spectrometer. The NiBr2 absorption spect
ra were taken under the supercritical water condition to demonstrate the ef
ficiency of the optical cell. (C) 2001 American Institute of Physics.