Beschreibung:
<jats:p>We demonstrate the use of hybrid rotational femtosecond/picosecond
(fs/ps) coherent anti-Stokes Raman spectroscopy (HR-CARS) as a
technique for temperature measurements in nitrogen gas at high
pressures and temperatures. A broadband pulse shaper-adjusted 42 fs
pulse interacts with a narrow-bandwidth, frequency-upconverted 5.5 ps
pulse in a cell containing <jats:inline-formula>
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</jats:inline-formula> at pressures of 1–70 atm and
temperatures of 300–1000 K. A computational code is used to model
spectra and fit experimental results to obtain best-fit temperatures.
We demonstrate good qualitative fits as well as good accuracy and
precision between thermocouple measured and best-fit temperatures over
the explored pressure and temperature regimes. The overall average
percentage temperature difference between thermocouple measurements
and best-fit temperatures is <jats:inline-formula>
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</jats:inline-formula> with a standard deviation of 7.1%,
showing the suitability of HR-CARS for characterizing high-pressure
and -temperature environments.</jats:p>