EXPERIMENTAL MEASUREMENT ON SPECTRAL PROPERTIES OF QUARTZ AT HIGH TEMPERATURE

Fused quartz can be encountered in many engineering applications, such as solar energy collection, infrared detection and plasma diagnostic etc. The thermal radiative properties are quite fundamental to the application of these materials. In recent years, some works have been concentrated on the experimental researches, identification strategies and properties reviews. However, the experiments at high temperature are inadequate, and the absorption coefficients acquired are usually at room temperature. In addition, the intensity of background stray radiation is much stronger than the effective signal at a higher temperature. The measurement details and the stray radiation suppression are very important to the high temperature experimental research. In the present study, an apparatus for spectral transmittance measurement from 0.83um to 2.5um has been built. The experimental maximum temperature was up to 1200 K. The contaminating radiation suppression and the measurement strategy, were proposed and analyzed based on the device. The next, transmittances of fused optical quartz samples of various thicknesses were measured. The spectral absorption coefficients and spectral refractive indexes were determined based on experimental data and theoretical computation at four different high-temperature levels.