Yang, Shu-Min; Guo, Ling-Ling; Nan, Bing; Zhao, Ying; Wu, Yan-Qing; Guo, Zhi; Tian, Chen; Zhao, Bo; Xue, Chao-Fan; Zhao, Jun; Song, Shuang; Liang, Zhen-Ye; Li, Li-Na; Wang, Yong; Tai, Ren-Zhong

NUCLEAR SCIENCE AND TECHNIQUES

2025, 1,

Yang, Shu-Min; Guo, Ling-Ling; Nan, Bing; Zhao, Ying; Wu, Yan-Qing; Guo, Zhi; Tian, Chen; Zhao, Bo; Xue, Chao-Fan; Zhao, Jun; Song, Shuang; Liang, Zhen-Ye; Li, Li-Na; Wang, Yong; Tai, Ren-Zhong

This paper describes the design and performance of the tender energy spectroscopy beamline (BL16U1), a phase II beamline, at the Shanghai Synchrotron Radiation Facility. The beamline, based on an in-vacuum undulator source with 26 mm period, provides an operable energy range between 2.1 keV and 16 keV, covering the K-edges of P to Rb and L3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm L_{3}$$\end{document}-edges of Zr to Bi. The principal optical elements of the beamline are a toroidal mirror, a liquid nitrogen-cooled double-crystal monochromator, a high-harmonic-rejection mirror, and two pairs of Kirkpatrick-Baez (KB) mirrors. Three end-stations, including non-focusing, microprobe, and sub-microprobe types, are installed on the beamline. X-ray fluorescence (XRF) and X-ray absorption spectroscopy (XAS), including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), are performed under vacuum or He atmosphere at the non-focusing end-station (with a beam spot size of similar to 670 mu mx710 mu m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim {670}\,{\upmu \hbox {m}}\times {710}\,{\upmu \hbox {m}}$$\end{document}). Using two KB mirrors systems, micro-XRF (mu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}XRF) mapping and micro-XANES (mu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}XANES) studies can be performed with a spot size of approximately similar to 3.3 mu mx1.3 mu m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim {3.3}\,{\upmu \hbox {m}}\times {1.3}\,{\upmu \hbox {m}}$$\end{document} at the microprobe end-station and with a smaller spot size of similar to 0.5 mu mx0.25 mu m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim {0.5}\,{\upmu \hbox {m}}\times {0.25}\,{\upmu \hbox {m}}$$\end{document} at the sub-microprobe end-station. The non-focusing end-station was officially opened to users in January 2024. The microprobe and sub-microprobe end-stations will be opened to users in the near future. This paper presents the characteristics, short-term technical developments, and early experimental results of this new beamline.