A prototype handheld X-ray diffraction instrument.
A prototype handheld X-ray diffraction instrument.
复制标题
原型手持式 X 射线衍射仪。
DOI：
10.1107/s1600576718012943
复制
发表时间：
2018
影响因子：
6.1
通讯作者：
Hansford G
中科院分区：
文献类型：
--
作者：
Hansford G
提出了一种手持式x射线衍射仪（HHXRD）的概念设计。该设计的核心是在反向反射几何结构中应用能量色散XRD （EDXRD）。这种技术带来了独特的优势，使手持式仪器格式，最值得注意的是，不敏感的样品形态和精确的样品位置相对于仪器。对于细粒样品，包括许多地质样品和大多数普通合金，这些特征否定了样品制备要求。通过对手持式x射线荧光仪器进行微小修改，开发出了HHXRD原型装置，并使用与采矿/采石相关的样品和广泛的金属样品对原型装置的性能进行了测试。例如，铁矿样品的矿物组成可以近似量化。在金属分析中，已经证明了主要相的识别和定量，以及晶格参数的提取。织构分析也是可能的，并给出了磷青铜样品的一个简单例子。除手持式以外的仪器格式是可能的，金属生产中的在线过程控制是一个有前途的领域。原型仪器需要延长测量时间，但有人认为，专门设计的仪器可以实现一分钟以下的数据采集时间。基于反向反射EDXRD的HHXRD受衍射峰分辨率低和荧光峰重叠干扰的限制，不能作为通用的XRD工具。然而，原位、无损和快速测量、不规则表面的公差以及在许多情况下不需要样品制备的优势是潜在的变革。对于分析符合商业相关性能标准的目标应用，HHXRD可以通过绝对的速度和便利性成为首选方法。
A conceptual design for a handheld X-ray diffraction (HHXRD) instrument is proposed. Central to the design is the application of energy-dispersive XRD (EDXRD) in a back-reflection geometry. This technique brings unique advantages which enable a handheld instrument format, most notably, insensitivity to sample morphology and to the precise sample position relative to the instrument. For fine-grained samples, including many geological specimens and the majority of common alloys, these characteristics negate sample preparation requirements. A prototype HHXRD device has been developed by minor modification of a handheld X-ray fluorescence instrument, and the performance of the prototype has been tested with samples relevant to mining/quarrying and with an extensive range of metal samples. It is shown, for example, that the mineralogical composition of iron-ore samples can be approximately quantified. In metals analysis, identification and quantification of the major phases have been demonstrated, along with extraction of lattice parameters. Texture analysis is also possible and a simple example for a phosphor bronze sample is presented. Instrument formats other than handheld are possible and online process control in metals production is a promising area. The prototype instrument requires extended measurement times but it is argued that a purpose-designed instrument can achieve data-acquisition times below one minute. HHXRD based on back-reflection EDXRD is limited by the low resolution of diffraction peaks and interference by overlapping fluorescence peaks and, for these reasons, cannot serve as a general-purpose XRD tool. However, the advantages of in situ, nondestructive and rapid measurement, tolerance of irregular surfaces, and no sample preparation requirement in many cases are potentially transformative. For targeted applications in which the analysis meets commercially relevant performance criteria, HHXRD could become the method of choice through sheer speed and convenience.