氟化锂椭圆弯晶分析器的特性及应用

设计了测试能量范围为0.6~6 keV的椭圆弯晶谱仪。此谱仪利用椭圆自聚焦原理,晶体分析器采用氟化锂材料,椭圆焦距为1 350 mm,离心率为0.958 6,布拉格角范围为30~65°。在神光Ⅱ靶室进行了实验,入射激光波长为0.35 μm,激光功率约为1.6×10¹⁴ W/cm²,与厚度为100 μm的钛平面靶法线夹角约为45°。实验结果证实,弯曲的氟化锂晶体具有极佳探测效果,弯晶分析器对波长为0.2~0.35 nm的X射线的分辨率可达500~1 000,同时具有等光程而便于空间分辨测量的优点,在同样距离条件下比平晶分析器高一个数量级的收光效率,故适合于激光等离子体X射线的光谱学研究。

Characteristics and application of elliptical curved LiF crystal analyzer

Based on the principle of elliptical focusing, an X-ray elliptical curved crystal analyzer whose measurement range,focal length,eccentricity and Bragg angel range are respectively 0.6~6 keV,1350 mm,0.9586 and 30°~60° was designed for investigating the laser producing plasmas. Aimed to the characteristic study of a high density plasma,a experiment was carried out with laser length of 0.35 μm,power of 1.6×10¹⁴ W/cm²,and the incident angel on the Ti plane of 45°. The result shows that the sensitivity of elliptical curved LiF crystal has very good detection ability,its calculated wavelength resolution is about 500~1 000 in the range of 0.2~0.35 nm. Experimental results also show that the curved crystal analyzer can be used in spatial resolution measurement for aplanatic property,its sensitivity is higher than a flat crystal. It suggests that curved LiF crystal analyzer is suitable for plasma diagnostic.