The Development of a Low-Energy, High-Resolution Synchrotron Radiation Beamline

小行星9512275 在美国路易斯安那州立大学先进微结构与器件中心（CAMD）的同步加速器上，将研制一条低能、高分辨率的光电发射光束线。 这是来自密歇根大学、内布拉斯加大学、德克萨斯大学、南方大学、田纳西大学和路易斯安那州立大学的科学家和教育工作者的共同努力。 高的动量和能量分辨率将被用来揭示在表面或薄膜中的新的物理和化学现象，如在表面的电荷密度波扭曲，费米表面不稳定性，和薄膜中的金属-非金属转变的存在。 低光子能量将用于研究薄膜中集体激发的发展，并探测包含过渡元素或稀土的相关电子系统的体性质。 高动量分辨率将有助于分子固体和重建半导体表面的色散测量。 低光子能量的波长可变能力对于研究分子光化学过程是必不可少的。 基于同步加速器的角分辨光电子能谱是唯一能够在扩展的能量范围内直接绘制固体能带的实验技术。 未来的挑战和机遇是将角分辨光电发射的能量分辨率推到所涉及的能量显著小于热能的极限。 这组研究人员在设计同步辐射分析仪器方面的经验可以导致对现有高分辨率光束线的显着改进。 ***

9512275 Plummer A low energy, high resolution photoemission beam line will be developed at the synchrotron at the Center for Advanced Microstructures and Devices (CAMD) of Louisiana State University. This is a joint effort of scientists and educators from the University of Michigan, the University of Nebraska, the University of Texas, Southern University, the University of Tennessee, and Louisiana State University. The high momentum and energy resolution will be utilized to uncover new physical and chemical phenomena at the surface or in thin films, such as the existence of charge density wave distortions at the surface, Fermi surface instabilities, and metal-nonmetal transitions in thin films. The low photon energy will be used to investigate the development of collective excitations in thin films and to probe the bulk properties of correlated electron systems containing transition elements or rare earths. The high momentum resolution will facilitate dispersion measurements for molecular solids and reconstructed semiconductor surfaces. The low photon energy variable wavelength capabilities are essential for investigating molecular photochemical processes. %%% Synchrotron-based angle-resolved photoemission is the only experimental technique capable of directly mapping the energy bands of a solid over an extended energy range. The challenge and the opportunity for the future is to push the energy resolution of angle-resolved photoemission to limits where the energies involved are significantly less than thermal energies. The experience of this group of researchers in the design of synchrotron radiation analysis instrumentation can lead to significant improvements over existing high-resolution beam lines. ***