Laboratory Bench-Top EXAFS with STJ Spectrometer

项目总结 扩展X射线吸收精细结构(EXAFS)光谱是一种给出元素特异性的技术 分子的结构和化学信息。EXAFS光谱的一个巨大优势是 它可以很容易地应用于许多不同类型的样品，包括溶液、粉末、浆液和动物 纸巾。目前的EXAFS仪器需要来自专门的同步辐射光源的明亮X射线束 对于大多数样本，这意味着访问仅限于优先研究，可以完成的科学是 由于需要在偏远地点工作，以及往往要等上几个月才能进入，这一点受到了限制。 STAR低温电子公司打算建造一台实验室仪器来测量传输到 同样的精度，通常在同步辐射光源和可比的信噪比下测量。这 该项目将涉及基于超导隧道结的改进的能量分辨率X射线探测器 (STJ)以实现能量分辨率和效率，使EXAFS测量在 常规实验室环境。第一个目标是设计和制造用于这些的新型STJ探测器芯片 下一代X射线探测器。星空冷冻电子公司将在之前钽基材成功的基础上再创辉煌 STJ将生产新型铝结，其钽吸收材料的能量可高达At 至少11,000辆电动汽车。随着我们改进设计和制造，该项目的这一部分将涉及广泛的测试 参数。第二个目标是将这种新的STJ探测器与样品室和宽带X射线耦合 一个完整的、用户友好的EXAFS仪器的源代码。与Second Aim相关的是一款重要的软件 开发项目，旨在为最终用户提供易于使用的工具。这将包括仪器 在数据采集过程中实时控制和处理EXAFS数据，以及在数据采集过程中分析数据的能力 数据采集。后一种能力不仅应提供初步结果，还应允许评估数据 和样品质量，从而优化仪器时间。 该项目的最终目标是使EXAFS成为常规的实验室技术，与更知名的 光谱，如紫外可见光谱、红外光谱和核磁共振光谱。而当 建议的实验室传输EXAFS仪器应与同步辐射光源互补 基于EXAFS，它应该会减少为EXAFS申请访问同步加速器的需要，开放 该技术用于更一般和常规的化学和生物应用，并使新的科学 机会和新的光谱应用。 1

PROJECT SUMMARY Extended X-ray absorption fine structure (EXAFS) spectroscopy is a technique that gives element-specific structural and chemical information about molecules. An enormous advantage of EXAFS spectroscopy is that it is readily applied to many different kinds of sample, including, solutions, powders, slurries, and animal tissues. Current EXAFS instruments require bright X-ray beams from specialized synchrotron lightsources for most samples, meaning that access is limited to priority research and the science that can be done is restricted by the need to work at remote sites as well as the often months-long wait for access. STAR Cryoelectronics intends to build a laboratory instrument to measure transmission EXAFS spectra to the same precision typically measured at synchrotron radiation sources and with comparable signal-to-noise. This project will involve improved energy-resolving X-ray detectors based on superconducting tunnel junctions (STJs) to achieve the energy resolution and efficiency needed to make EXAFS measurements feasible in a regular laboratory setting. The first aim is a plan to design and fabricate novel STJ detector chips for these next-generation X-ray detectors. STAR Cryoelectronics will build on previous success with tantalum-based STJs to produce novel aluminum junctions with tantalum absorbers capable of functioning to energies up to at least 11,000 eV. This part of the project will involve extensive testing as we refine the design and fabrication parameters. A second aim is to couple this new STJ detector with a sample chamber and broadband X-ray source to a complete, user-friendly EXAFS instrument. Associated with second aim is a significant software development project, intended to provide the end user an easy-to-use instrument. This will include instrument control, processing of EXAFS data in real-time during data acquisition, and the ability to analyze data during data acquisition. This latter ability should not only provide preliminary results, but allow assessment of data and sample quality, thereby optimizing instrument time. This project’s ultimate aim is to make EXAFS a routine laboratory technique, alongside more well-known spectroscopies such as UV-visible spectroscopy, IR spectroscopy, and NMR spectroscopy. While the proposed laboratory transmission EXAFS instrument should be complementary to synchrotron lightsource based EXAFS, it should nonetheless reduce the need to apply for access to synchrotrons for EXAFS, open up the technique for more general and routine chemical and biological applications, and enable new scientific opportunities and novel spectroscopic applications. 1