The Radiation Temperature Characteristics of Sapphire under Shock Loading

Abstract

A light gas gun was used to study the radiation temperature from the window material of sapphire. The luminescence characteristics were determined using a multi-wavelength pyrometer in the pressure range of 36–50 GPa. By improving the processing technology for the metal sample and assembly technology for the target, the eight-wavelength light radiation was measured from sapphire under shock pressure without phase transition. The experimental results showed that sapphire has luminous phenomenon from 36.5 GPa. The luminous intensity changes in a linear fashion, revealing the thickness of the radiating layer of shock-compressed sapphire with a constant absorption coefficient. The results indicated that the spectral distribution is a typical thermal radiation, which fits well with the grey-body spectrum. The radiation of sapphire under shock mostly came from the adiabatic shear banding, as determined by comparing the melting line of sapphire using a static high-pressure experiment and theoretical calculations with the radiation temperature. The study is an effective means to obtain the transparent material shock radiation temperature. Moreover, an effective approach is proposed to research the radiation mechanism of transparent material and the high pressure melting line.