An alternative method for high-precision calibration for dynamic pyrometry measurements above 2500 K

Experiments in shock physics often use optical pyrometry to determine temperature of dynamically compressed materials. While tungsten ribbon lamp provides a known radiance at certain wavelengths, the calibration is made at temperatures T \textless 3000 K, while most of the experimental measurements are made at T \textgreater 3000 K, resulting in substantial extrapolation errors. This talk presents a concept and initial tests for the calibration of a streaked spectroscopy system used for optical pyrometry. The streaked spectroscopy system relies upon measuring the total system response (as counts J$^{\mathrm{-1}}$ nm$^{\mathrm{-1}}$ sr$^{\mathrm{-1}})$ which aims to lower the uncertainty of temperature readings. The process uses a tunable monochromator, a NIST-traceable calibrated power meter, and a streaked spectrometer. Further, we have used the streaked spectroscopy system to measure the temperatures of a shocked z-cut quartz crystal at 93 and 99 GPa, and the results are found to agree with the literature. Sensitivities to various error sources are discussed. The combined uncertainties due to these errors are determined, the relative error from calibration and wavelength assignment, and estimated the overall uncertainty in the measurement is found to be about 1{\%} at 5500 K, which is a substantial improvement over other methods that eliminates errors due to extrapolation from calibration at lower temperatures (e.g., tungsten lamps).