Variable exit beam height double‐crystal monochromator for high‐power insertion devices
Variable exit beam height double‐crystal monochromator for high‐power insertion devices
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用于高功率插入装置的可变出射光束高度双晶单色仪
DOI：
10.1063/1.1146622
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发表时间：
1996
影响因子：
1.6
通讯作者：
Y. Kuwahara
中科院分区：
文献类型：
--
作者：
H. Oyanagi;K. Haga;Y. Kuwahara
在Photon Factory制造并测试了用于高功率插入器件的可变出射光束高度双晶体单色器。第二个晶体安装在高精度XY平移平台上，其在平行和垂直于反射平面（x，y）方向上的位置由计算机控制。在该设计中，出射光束高度（y）和第二晶体的几何所需定位（x）被分开控制。在布拉格角（θ）从6°到25°的范围内获得固定或可变的出射光束高度。当同时控制x和y时，在扩展的x射线吸收精细结构谱中观察到由两个晶体之间的平行性退化引起的系统噪声。这种噪声通过（x，y）的多功能控制而显著降低：对于典型扫描（101 keV），仅允许y变化，而当单色器在更宽的能量范围内调谐时，两个坐标都被控制。
A variable exit beam height double‐crystal monochromator for high‐power insertion devices was built and tested at the Photon Factory. The second crystal is mounted on a high‐precision XY translational stage and its position in the parallel and perpendicular direction to the reflecting plane (x,y) is computer controlled. In this design, the exit beam height (y) and geometrically required positioning of the second crystal (x) are separately controlled. Either a fixed or variable exit beam height is obtained over the Bragg angle (θ) range from 6° to 25°. A systematic noise caused by degraded parallelity between the two crystals is observed in extended x‐ray absorption fine structure spectra when x and y are simultaneously controlled. This noise is significantly reduced by a versatile control of (x,y): for a typical scan (∼1 keV) only y is allowed to vary while both coordinates are controlled when a monochromator is tuned over a wider energy range.