Experimental apparatus for radiation characteristics of semi-transparent materials at high temperature:A direct radiometric method

The accurate determination of radiation characteristics for semi-transparent materials is essential for the transmission of radiation energy and optical signals at high temperatures. However, distinguishing spontaneous, transmitted, and background radiation in the signals received by the detector poses significant challenges due to the inherent properties of semi-transparent materials. To address this, an experimental apparatus based on the direct radiometric method has been established, operating within a temperature range of 473-1473 K and a wavelength range of 3-12 mu m. An integrated approach that employs an ancillary blackbody is introduced to simultaneously measure radiation characteristics of semi-transparent materials. The reliability of experimental equipment and method is evaluated through the measurement of radiation characteristics of silicon carbide and sapphire samples. Additionally, the variation of transmissivity, emissivity, and reflectivity of the sapphire sample is analyzed at various temperatures, exploring the trends of these parameters with respect to temperature and wavelength.