Cryogenically cooled bent double-Laue monochromator for high-energy undulator X-rays (50-200 keV).
Cryogenically cooled bent double-Laue monochromator for high-energy undulator X-rays (50-200 keV).
复制标题
用于高能波荡器 X 射线（50-200 keV）的低温冷却弯曲双劳厄单色仪。
DOI：
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发表时间：
2002
影响因子：
2.5
通讯作者：
P. Lee
中科院分区：
文献类型：
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作者：
S. Shastri;K. Fezzaa;A. Mashayekhi;W. K. Lee;P. Fernandez;P. Lee
一台用于高能X射线的液氮冷却单色仪已经在高级光子源(APS)的SRI-CAT扇区1波荡器光束线上运行了两年多。该单色器由两个弯曲的Si(111)劳厄晶体组成，根据罗兰条件进行调整。在不增加能量宽度(DeltaE/E约为10(-3))的情况下，它在高能下提供的助熔剂是平板单色仪的十倍以上。低温冷却允许最佳的流量，避免了经常使用的替代过滤技术的牺牲-这一技术在7GeV APS等源中不太有效，在这些源中，相当大的热负载可以由高能光子沉积，特别是在关闭的波荡器间隙。固定偏移量的几何结构提供了完全可调的同轴单色光束。除了介绍低温冷却晶体在高热负荷下的光学性能、独特的晶体设计和稳定的弯曲机制外，还描述了弯曲半径的调整过程。
A liquid-nitrogen-cooled monochromator for high-energy X-rays consisting of two bent Si(111) Laue crystals adjusted to sequential Rowland conditions has been in operation for over two years at the SRI-CAT sector 1 undulator beamline of the Advanced Photon Source (APS). It delivers over ten times more flux than a flat-crystal monochromator does at high energies, without any increase in energy width (DeltaE/E approximately 10(-3)). Cryogenic cooling permits optimal flux, avoiding a sacrifice from the often employed alternative technique of filtration - a technique less effective at sources like the 7 GeV APS, where considerable heat loads can be deposited by high-energy photons, especially at closed undulator gaps. The fixed-offset geometry provides a fully tunable in-line monochromatic beam. In addition to presenting the optics performance, unique crystal design and stable bending mechanism for a cryogenically cooled crystal under high heat load, the bending radii adjustment procedures are described.