jo5043.pdf (1.57 MB)
Download file

A prototype handheld X-ray diffraction instrument

Download (1.57 MB)
journal contribution
posted on 25.07.2019, 15:32 by G. Hansford
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.

Funding

This work was supported by the Science and Technology Facilities Council (grant Nos. ST/L000148/1 and ST/ P001874/1).

History

Citation

Journal of Applied Crystallography, 2018, 51, pp. 1571-1585

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Journal of Applied Crystallography

Publisher

International Union of Crystallography, Wiley

issn

0021-8898

Acceptance date

13/09/2018

Copyright date

2018

Available date

25/07/2019

Publisher version

http://scripts.iucr.org/cgi-bin/paper?S1600576718012943

Notes

This article has supporting information at https://doi.org/10.1107/S1600576718012943/jo5043sup1.pdf

Language

en