The optical scheme of a flat-field stigmatic X-ray spectrograph, which includes a grazing-incidence focusing mirror and a concave fan-type diffraction grating crossed with respect to the mirror and mounted in a conical diffraction scheme, is calculated analytically. Spectral images of a point monochromatic source are obtained by numerical ray tracing, confirming the high quality of spectral images at a level of 1 × 4 μm. It is assumed that the use of small grazing incidence angles in combination with the application of multilayer reflective coatings, including aperiodic ones, will make it possible to extend the working spectral range of the stigmatic spectrograph to the region of the ‘tender’ (ℏω ≈ 1.5 – 6 keV) X-ray range.

中文翻译：

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基于圆锥衍射的散点平场 X 射线摄谱仪的概念

分析计算了平场像散X射线光谱仪的光学方案，该光谱仪包括一个掠入射聚焦镜和一个与镜交叉并安装在圆锥衍射方案中的凹面扇形衍射光栅。通过数值光线追踪获得点单色源的光谱图像，证实了 1×4 μm 水平的高质量光谱图像。假设使用小掠入射角与多层反射涂层（包括非周期性涂层）的应用相结合，将有可能将像散光谱仪的工作光谱范围扩展到“招标”区域（ℏω≈ 1.5 – 6 keV) X 射线范围。