New method for focusing x rays and gamma rays
New method for focusing x rays and gamma rays
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聚焦 X 射线和伽马射线的新方法
DOI：
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发表时间：
1982
期刊：
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通讯作者：
R. Smither
中科院分区：
文献类型：
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作者：
R. Smither
描述了一种聚焦x射线和伽马射线的新方法，该方法可以将来自点源或平行光束的单色辐射聚焦到线像上。如果使用两个聚焦元件，或者如果使用在两个方向上弯曲的单个元件，则可以将辐射聚焦到点图像。相反，来自点源的辐射可以转换成平行光束。该方法利用弯曲衍射晶体，其中晶间平面间距随晶体位置的变化而变化。单色辐射衍射的布拉格角现在将作为晶体中位置的函数而变化，这个新的自由度可以用来获得衍射光束的聚焦。本文讨论了实现晶体平面间距变化的多种方法，包括热梯度的使用和晶体元素组成的变化。这种新的聚焦系统在伽玛射线望远镜上的应用，以及在实际成像中的应用。
A new method for focusing x rays and gamma rays is described that can focus monochromatic radiation from a point source or parallel beam down to a line image. If two focusing elements are used or if a single element bent in two directions is used, the radiation can be focused to a point image. Conversely, radiation from a point source can be converted into a parallel beam. The method makes use of bent diffraction crystals in which the intercrystalline‐plane spacing is varied as a function of position in the crystal. The Bragg angle for diffraction of monochromatic radiation will now vary as a function of position in the crystal, and this new degree of freedom can be used to obtain focusing of the diffracted beam. A number of ways to achieve this variation in crystal‐plane spacing is discussed, including the use of thermal gradients and the variation of the elemental composition of the crystal. The applications of this new focusing system to a gamma‐ray telescope and to the production of a real image of a ...