冲击压缩过程中蓝宝石的发光辐射现象与其在高压下的透明性、结构相变密切相关。采用密实金属与蓝宝石窗口直接接触的靶结构,在二级轻气炮加载平台上研究了蓝宝石在高于兆巴压力(100 GPa)区域的发光辐射特性。利用多通道辐射高温计得到了含有金属界面辐射的典型的发光辐射信号,通过辐射输运模型得到了蓝宝石自身的辐射强度。结果表明:在兆巴以上压缩区域,蓝宝石的辐射温度随压力变化出现明显的拐折,在87 GPa压力附近蓝宝石发生冲击压缩结构相变。

The optical radiation of sapphire during shock compression process is closely related to its transparency and structural phase transition under high pressure. This study investigates the optical radiation characteristics of sapphire above megabar pressure (namely, 100 GPa) on the loading platform of two-stage light-gas gun using the target structure of direct contact between dense metal and sapphire window. A typical optical radiation signal containing metal-interface radiation is obtained using a multi-channel radiation pyrometer. The radiation through sapphire is determined using the radiative transfer model. Results show that the change in radiation temperature of sapphire in the shock-compression region under the pressure above megabar is found to show a significant turning and the shock-induced structural phase transition of sapphire occurs under the pressure near to 87 GPa.