MRI: Development of a Harmonic Rejection Optical System for the MR-CAT Beamline

这项来自重大研究仪器计划的奖项支持伊利诺伊理工学院建造晶体光学谐波抑制系统。该系统用于先进光子源(APS)材料研究协作访问团队(MR-CAT)的波荡器光束线。该系统配备了不同的光学元件，被称为“光束清洁器”，将增强我们的电流镜系统在低能(低于30keV)时的谐波抑制，为X射线吸收光谱实验提供中能(30keV至45keV)的谐波抑制，并使我们能够无谐波地获得非常高的能量(高达80keV)，用于衍射和对分布函数实验。该系统的设计是由于需要将对准作为常规的改变能量、投放在聚焦镜中或在不同的探测器中滚动。此外，在X射线光谱学实验中扫描主光束线单色仪时，适当的设计将减少垂直光束的运动。该仪器在三种模式中的一种，将在MR-CAT完成的几乎所有实验中得到应用，进行目前困难的实验，需要较长的对准时间或使用MR-CAT设施的用户可以访问的专用光束线。主要研究仪器计划支持伊利诺伊理工学院建造晶体光学谐波抑制系统。该仪器将进入先进光子源的材料研究协作访问团队(MR-CAT)实验站。该系统将允许常规地改变到达样品的X射线的特性，就像人们改变X射线能量、聚焦或各种探测器以适应手头的材料和实验一样。该仪器的关键部件是运动台和“光束清洗器”带通光学元件，它们利用了强弯曲单晶Si和Ge的良好的反射率和取向特性。将该设备与MR-CAT光谱学和粉末衍射光束线相结合，包括安装的微聚焦能力，将通过提高中高能(30keV)X射线吸收光谱实验的信噪比来增强能力，在任何能量下产生用于光谱实验的几乎固定的出射光束，并在波动光束线上进行实际的高能对分布函数(PDF)测量。该仪器是专门为在MR-CAT实验站的不同位置移动和快速安装而设计的。

This award from the Major Research Instrumentation program supports Illinois Institute of Technology with the construction of a crystal optic harmonic rejection system. The system is for the Materials Research Collaborative Access Team (MR-CAT) undulator beamline at the Advanced Photon Source (APS). This system, outfitted with different optics, known as "beam cleaners", will enhance the harmonic rejection of our current mirror system at low energies (below 30keV), provide harmonic rejection for x-ray absorption spectroscopy experiments at intermediate energies (30keV to 45keV) and give us harmonic-free access to very high energies (up to 80keV) for diffraction and pair distribution function experiments. The design of the system is driven by the need to make alignment as routine as changing energy, dropping in a focusing mirror or rolling in a different detector. In addition, proper design of this instrument will reduce vertical beam motion as the primary beamline monochromator is scanned for x-ray spectroscopy experiments. This instrument, in one of its three modes, will find application in nearly all of the experiments done at the MR-CAT, making what are currently difficult experiments, requiring long alignment times or the use of a dedicated beamline accessible to users of the MR-CAT facility.The Major Research Instrumentation program supports Illinois Institute of Technology with the construction of a crystal optic harmonic rejection system. The instrument will drop in to the Materials Research Collaborative Access Team (MR-CAT) experimental station at the Advanced Photon Source. The system will permit to change routinely the characteristics of the x-rays reaching the sample, just as one change the x-ray energy, focusing or kinds of detectors to suit the material and experiment at hand. The key elements of the instrument are a kinematic table and ``beam cleaner'' band pass optics which take advantage of the favorable reflectivity and alignment properties of strongly bent single crystals of Si and Ge. The combination of this device with the MR-CAT spectroscopy and powder diffraction beamline, including the installed microfocusing capability, will enhance the capabilities by improving the signal to noise in x-ray absorption spectroscopy experiments at moderately high energies (30keV), produce a nearly fixed exit beam for spectroscopy experiments at any energy and make practical high energy pair distribution function (PDF) measurements at an undulator beamline. The instrumentation is specifically designed to be moved and rapidly installed in various locations in the MR-CAT experimental station.