High Efficiency X-Ray Detector for Electron Microscopy

用于电子显微镜的高效 X 射线探测器

• 批准号: 6881807
• 负责人: Carolyn Rossington Tull
• 金额: $ 10万
• 依托单位: PHOTON IMAGING, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-18 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881807
• 关键词: X ray spectrometry; analytical chemistry; analytical method; bioengineering /biomedical engineering; biomedical equipment development; biosensor device; computer program /software; electron microscopy; transmission electron microscopy

DESCRIPTION (provided by applicant): We propose to develop the next generation of x-ray detectors for analytical electron microscopy that will offer larger solid angle (thus higher sensitivity), higher count rate capability, and higher detection efficiency, to match the next generation of analytical electron microscopes which will offer the opportunity for unprecedented analytical measurements in biological applications. Smaller areas (<1 nm spatial resolution), for structural and chemical analysis, and higher sensitivities than ever before will be possible. One of the standard analytical tools on almost all electron microscopes (EM) is an energy dispersive spectroscopy (EDS) detector used for chemical analysis. However, there are many limitations with the current generation of EDS detectors for EM and TEM. The proposed new EDS detectors will be based on the silicon multi-cathode detectors (SMCD) that Photon Imaging has been developing for a number of different x-ray fluorescence (XRF) and x-ray diffraction (XRD) applications. Unlike with traditional Si(Li) or HPGe EDS detectors, these new detectors do not require liquid nitrogen, which makes them extremely compact and very flexible in their mechanical design, which can open up new possibilities in measurements capabilities. In addition, they are capable of operating at much higher count rates than traditional EDS detectors. Recently, we have begun to develop very thick SMC detectors (up to 1.5 mm thick). This extra thickness (beyond the standard 0.35 mm) offers an extended detection efficiency for hard x-rays, up to 40 keV. In Phase I, we will evaluate the x-ray performance of the new, 10-20 mm2, high efficiency SMCD detectors for TEM applications. The spectrometer will be designed to fit tightly into the EM probe area, to maximize the solid angle for signal collection, while not interfering with the pole piece nor other analytical equipment. The detector and spectrometer will be thoroughly evaluated at Photon, using radioisotope sources and an x-ray generator, and then will be evaluated on the EM, in conjunction with Dr. Nestor Zaluzec, who will consult on this project. In Phase II, we will develop larger area 50 mm2 detectors, the full prototype commercial spectrometer, with full data acquisition software, for insertion into commercially available TEMs and other types of EMs.

描述（由申请人提供）：我们建议开发用于分析电子显微镜的下一代X射线探测器，其将提供更大的立体角（因此更高的灵敏度），更高的计数率能力和更高的检测效率，以匹配下一代分析电子显微镜，其将为生物应用中前所未有的分析测量提供机会。用于结构和化学分析的更小区域（<1 nm空间分辨率）以及比以往更高的灵敏度将成为可能。几乎所有电子显微镜（EM）上的标准分析工具之一是用于化学分析的能量色散光谱（EDS）检测器。然而，当前一代用于EM和TEM的EDS检测器存在许多限制。新的EDS探测器将基于硅多阴极探测器（SMCD），Photon Imaging已经开发了许多不同的X射线荧光（XRF）和X射线衍射（XRD）应用。与传统的Si（Li）或HPGe EDS探测器不同，这些新探测器不需要液氮，这使得它们在机械设计上非常紧凑和灵活，这可以在测量能力方面开辟新的可能性。此外，它们能够以比传统EDS探测器高得多的计数率工作。最近，我们已经开始开发非常厚的SMC探测器（厚度高达1.5 mm）。这种额外的厚度（超过标准的0.35 mm）为硬X射线提供了更高的检测效率，高达40 keV。在第一阶段，我们将评估用于TEM应用的新型10-20 mm 2高效SMCD探测器的X射线性能。光谱仪将被设计成紧密地配合到EM探针区域中，以最大化信号收集的立体角，同时不干扰极片或其他分析设备。探测器和光谱仪将在Photon使用放射性同位素源和X射线发生器进行彻底评估，然后将与Nounge Zaluzec博士一起在EM上进行评估，Nounge Zaluzec博士将就此项目提供咨询。在第二阶段，我们将开发更大面积的50平方毫米探测器，完整的原型商业光谱仪，完整的数据采集软件，插入到商业上可用的TEM和其他类型的EM。