X‐ray optics of doubly curved diffractors
X‐ray optics of doubly curved diffractors
复制标题
双曲面衍射仪的 X 射线光学器件
DOI：
10.1063/1.345629
复制
发表时间：
1990
影响因子：
3.2
通讯作者：
Songquan Sun
中科院分区：
文献类型：
--
作者：
D. B. Wittry;Songquan Sun
描述了四种类型的双弯曲衍射器的X射线光学的计算，并将结果与单弯曲衍射器（Johann和Johansson几何）的类似结果进行了比较。在这些计算中，当衍射器在15至75度的布拉格角范围内使用时，对于与布拉格角的给定偏差，确定弯曲衍射器表面上的点的轨迹。所讨论的六种情况包括圆柱形、球形和环形几何形状。这些计算被用作比较收集效率和光谱分辨率时，这些衍射器被用于扫描单色仪的基础。它示出，双弯曲的衍射器是上级单弯曲的，并与球面和环面的衍射器提供了最好的性能的所有考虑的衍射器，如果一个广泛的布拉格角必须被覆盖。
Calculations of the x‐ray optics of four types of doubly curved diffractors are described and the results are compared with similar results for singly curved diffractors (Johann and Johansson geometry). In these calculations the locus of points on a curved diffractor’s surface is determined for a given deviation from the Bragg angle when the diffractor is used at Bragg angles ranging from 15 to 75 degrees. The six cases discussed include cylindrical, spherical, and toroidal geometries. The calculations are used as a basis for comparing the collection efficiency and the spectral resolution when these diffractors are used in scanning monochromators. It is shown that doubly curved diffractors are superior to singly curved ones and that a diffractor with spherical planes and toroidal surface provides the best performance of all of the diffractors considered if a wide range of Bragg angles must be covered.