A Device for Selecting and Rejecting X-ray Harmonics

描述（由申请人提供）： 同步辐射是利用X射线衍射、X射线散射和X射线吸收光谱进行结构生物学研究的重要工具。数据的质量通常主要取决于光束光谱质量。光束线的技术限制（例如能量范围）可以决定实验的成败。 在本申请中，我们提出了优化，设计，构造，并在广泛的能量范围内测试一种新颖的，廉价的，易于对齐的设备（“光束清洁器”）。该装置具有若干益处：改善X射线束光谱质量;通过选择特定谐波用于实验用途来扩展（例如，三倍）第三代同步辐射源处的现有光束线的有用能量范围;随着单色器角度改变而被动地补偿垂直光束运动;以及聚焦光束。光束清洁器提供了简化新的光束线设计的潜力，允许在真空中使用通道切割单色器，随后是一个光束清洁器，以便被动地补偿垂直光束运动，而不需要精确的真空机械。该装置还可用作非射束硬化可变衰减器，用于在强第三代源下对辐射敏感的生物样品进行实验，并且该装置似乎也适用于实验室研究。

DESCRIPTION (provided by applicant): Synchrotron radiation is an important tool for structural biological studies using X-ray diffraction, X-ray scattering, and X-ray absorption spectroscopy. The quality of data often depends critically on beam spectral quality. The technical limitations (e.g. energy range) of beamlines can make or break experiments. In this application we propose to optimize, design, construct, and test over a wide range of energies a novel, inexpensive, easy to align device ("beam cleaner"). The device has several benefits: improving X-ray beam spectral quality; extending (e.g. tripling) the useful energy range of existing beamlines at third generation synchrotron radiation sources by selecting specific harmonics for experimental use; passively compensating for vertical beam motion as the monochromator angle is changed; and focussing the beam. Beam cleaners offer the potential to simplify new beamline designs by permitting use of channel-cut monochromators in vacuum, followed by a beam cleaner arranged so as to passively compensate for vertical beam motion, without the need for precise in-vacuum mechanics. This device also potentially can be used as a non-beam-hardening variable attenuator for experiments on radiation sensitive biological samples at intense third generation sources, and the devices also appear to be applicable to laboratory research.