Enhancement of a Synchrotron Beamline for Magnetics Research and Education

这笔拨款支持磁学研究和教育的同步加速器光束线的增强。新一代自旋电子材料的发展正在发生，需要有针对性的设施来表征磁性与电子和物理结构之间的关系。这笔拨款通过对LSU CAMD同步加速器光源的现有光束线进行重大投资来满足这一需求。此次升级将利用圆偏振光在三维过渡金属l边的能量上改进磁性材料的表征。升级包括两组改进。首先，当前的平面光栅单色仪光束线将被增强，以允许使用可调谐的圆偏振同步加速器光。将建造步进电机控制的冷却挡板，以从轨道的上下部分提取圆偏振光。光束线被设计成容纳两个光栅，一个新的300 - 1200 eV的光栅将被安装以扩展当前的光子能量范围。最后，在光束线上的最后一个光学元件之外安装一个三反射偏振器来测量光的偏振度。第二个组件是提供样品制备的通用用户端站，用于原位膜生长的蒸发器和用于磁化样品的线圈。光谱学将包括总产率测量和光发射，并提供当前LEED和RHEED仪器的包含。这项改进将利用来自路易斯安那州、内布拉斯加州、阿拉巴马州的NSF-MINT中心和伊利诺伊州的一组磁性材料研究人员的投资，并提供一种简单但可靠的方法来表征广泛的磁性材料。该光源位于该国服务不足的地区，提供的通道满足了研究的需要

This grant supports enhancement of a synchrotron beamline for magnetics research and education. Development of a new generation of spintronic materials is occurring and there is a need for facilities targeted to characterize the relationship between magnetic properties and electronic and physical structures. This grant addresses this need by leveraging a significant investment in the existing beamline at the LSU CAMD synchrotron light source. The upgrade will provide for improved characterization of magnetic materials using circularly polarized light at energies spanning the L-edges of 3d transition metals. The upgrade consists of two sets of improvements. First, the current plane-grating monochromator beamline will be enhanced to allow for the use of tunable, circularly polarized synchrotron light. Stepper-motor controlled, cooled baffles will be constructed to extract circularly polarized light from the upper and lower portions of the orbit. The beamline was designed to accommodate two gratings, and a new, 300 - 1200 eV, grating will be installed to extend the current photon energy range. Finally, a triple-reflection polarizer will be installed beyond the last optical element in the beamline to measure the degree of light polarization. A second component is a general-purpose user-endstation to provide for sample preparation, evaporators for in-situ film growth, and coils for magnetizing samples. Spectroscopy will include total yield measurements as well as photoemission and provide for inclusion of current LEED and RHEED instrumentation. This enhancement will leverage investments in a group of magnetic materials researchers from Louisiana, Nebraska, Alabama's NSF-MINT Center, and Illinois and provide for a simple but reliable method to characterize a broad range of magnetic materials. The access provided by the location of this light source, located in an underserved region of the country, serves the needs of researche