Abstract Beamline 8 is a bending magnet beamline at Synchrotron Light Research Institute (SLRI) in Thailand and has been opened for synchrotron users to perform X-ray absorption fine structure (XAFS) spectroscopy since 2006. The beamline was originally equipped with a double crystal monochromator (DCM) using a vertical entrance slit in order to limit divergence of a white beam, thus optimizing photon energy resolution at a cost of photon flux. In 2016 the beamline was upgraded with a vertical collimating mirror to decrease beam divergence. The maximum photon flux is consequently increased to 3 × 1011 photons s−1 (100 mA)−1 at the phosphorus K-edge (2145.5 eV). This enhances beamline utilization for phosphorus speciation and analysis of local atomic structures in diluted samples (>50 mg/kg of phosphorus). Furthermore, the highest photon energy of the beamline has been extended from 10 keV to 13 keV, enabling several heavy elements such as lead to be studied while the lowest photon energy currently covers the sodium K-edge. To demonstrate improved XAFS performance, XAFS experiments were carried out on selected samples (NaCl, Na3PO4·12H2O, PbO, PbO4, PbCO3, PbS, soil, and historical paint); quality of the experimental spectra was evaluated in terms of signal-to-noise ratio and appearance of XAFS characteristic features.

中文翻译：

---

在 1 keV 到 13 keV 的光子能量范围内升级用于 XAFS 光谱的 SLRI BL8 光束线

摘要 Beamline 8 是泰国同步加速器光研究所（SLRI）的弯曲磁铁光束线，自 2006 年起开放给同步加速器用户进行 X 射线吸收精细结构（XAFS）光谱分析。该光束线最初配备双晶单色器(DCM) 使用垂直入口狭缝来限制白色光束的发散，从而以光子通量为代价优化光子能量分辨率。2016 年，光束线升级为垂直准直镜，以减少光束发散。因此，最大光子通量在磷 K 边缘 (2145.5 eV) 处增加到 3 × 1011 光子 s-1 (100 mA)-1。这提高了对稀释样品（> 50 毫克/千克磷）中磷形态和局部原子结构分析的光束线利用率。此外，光束线的最高光子能量已从 10 keV 扩展到 13 keV，从而可以研究铅等几种重元素，而目前最低光子能量覆盖钠 K 边缘。为了证明改进的 XAFS 性能，对选定的样品（NaCl、Na3PO4·12H2O、PbO、PbO4、PbCO3、PbS、土壤和历史涂料）进行了 XAFS 实验；根据信噪比和 XAFS 特征的外观评估实验光谱的质量。