Quantitative X-Ray Microanalysis of Bulk Materials at High Energy (60-400 keV)

本项目的目标是设计一种简单、可靠和高效的工具，用于在透射电子显微镜（TEM）下对60至400 keV的大块样品进行定量x射线微分析。目前还不存在这样的工具。2009年，Bruker推出了第一台硅漂移探测器（SDD），该探测器可以安装在TEM中，至少提供50万次/秒的光子计数率，能量分辨率与Si(Li) EDS探测器相似。第一个SDD探测器被安装在hydro - quacimbec研究中心的场发射扫描透射电子显微镜（FE-STEM） Hitachi HD-2700上。现在可以在电子能量大于60kev的TEM中获得体试样的x射线光谱。然而，对电子能量高于60 keV的x射线能谱进行定量的x射线微分析是不可能的，因为已经存在的大量样品的定量模型是针对低于30 keV的电子束能量开发的，电子探针和扫描电镜使用的电子能量。该合作研究基金将与Bruker和hydro - qu<s:1>合作开发一种方法，用于在60 - 400 keV范围内对散装样品进行定量x射线微分析。期望在TEM中对块状试样进行定量x射线微分析，降低微量元素的检出限。最后，将比较30和200 keV之间的块状材料分析，以显示这些能量用于块状样品的定量x射线微分析的优势和局限性。

The objective of this project consists of elaborating a simple, reliable and efficient tool for quantitative x-ray microanalysis of bulk specimen in the transmission electron microscope (TEM) for electron energies from 60 to 400 keV. Such tools do not exist presently. In 2009, Bruker introduced the first Silicon Drift Detector (SDD) that can be installed in a TEM that provides, at least, a photon count rate of 500 000 counts/s with energy resolution similar to Si(Li) EDS detectors. The first SDD detector was installed to the Field Emission Scanning Transmission Electron Microscope (FE-STEM) Hitachi HD-2700 of Hydro-Québec Research Center. It is now possible to acquire x-ray spectra of bulk specimen in the TEM for electron energy above 60 keV. However, quantitative x-ray microanalysis of x-ray spectra acquired for electron energies above 60 keV is not possible because the quantitative models that already exist for bulk specimen were developed for electron beam energy below 30 keV, the electron energies used by the electron microprobe and the SEM. This collaborative research grant is to develop, in collaboration with Bruker and Hydro-Québec, a method to perform quantitative x-ray microanalysis of bulk specimen in the 60 - 400 keV range. It is expected that quantitative x-ray microanalysis of bulk specimen in the TEM will lower the detection limit of trace elements. Finally, comparisons will be performed for the analysis of bulk materials between 30 and 200 keV in order to show the advantages and limitations of these energies for quantitative x-ray microanalysis of bulk specimens.