Energy-dispersive X-ray diffraction analyser comprising a substantially X-ray transparent member having an improved reflection geometry

Patent metadata

Field	Value
Publication number	US-11614414-B2
Application number	US-201917285226-A
Country	US
Kind code	B2
Filing date	Oct 15, 2019
Priority date	Oct 19, 2018
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

An on-line energy dispersive X-ray diffraction (EDXRD) analyser for mineralogical analysis of material in a process stream or a sample is disclosed. The analyser includes a collimated X-ray source to produce a diverging beam of polychromatic X-rays, and an energy resolving X-ray detector, and a substantially X-ray transparent member having the form of a solid of revolution which is circularly symmetric about a central axis between the collimated X-ray source and the energy resolving X-ray detector, an outer surface of the X-ray transparent member positionable adjacent the material to be analysed. A primary beam collimator is disposed adjacent to or within the substantially X-ray transparent member to substantially prevent direct transmission of polychromatic X-rays emitted from the source to the detector. The analyser is configured such that the diverging beam of polychromatic X-rays are directed towards the substantially X-ray transparent member, and where the energy resolving X-ray detector collects a portion of the beam of X-rays diffracted by the material and outputs a signal containing energy information of the collected, diffracted X-rays.

First claim

The invention claimed is:

1. An on-line energy-dispersive X-ray diffraction (EDXRD) analyser for a mineralogical analysis of a material in a process stream or a sample, the on-line EDXRD analyser comprising:
a collimated X-ray source to produce a diverging beam of polychromatic X-rays;
an energy-resolving X-ray detector;
a substantially X-ray transparent member having a form of a solid of revolution, which is circularly symmetric about a central axis between the collimated X-ray source and the energy-resolving X-ray detector, an outer surface of the substantially X-ray transparent member positionable adjacent the material to be analysed; and
a primary beam collimator disposed adjacent to or within the substantially X-ray transparent member, and configured to substantially prevent a direct transmission of the diverging beam of polychromatic X-rays emitted from the collimated X-ray source to the energy-resolving X-ray detector;
where the on-line EDXRD analyser is configured such that the diverging beam of polychromatic X-rays are directed towards the substantially X-ray transparent member, and where the energy-resolving X-ray detector collects a portion of a beam of X-rays diffracted by the material and outputs a signal containing energy information of the collected portion of diffracted beam of X-rays.

2. The on-line EDXRD analyser according to claim 1 , further comprising a detector collimator comprising an aperture, which further defines the portion of the beam of X-rays diffracted by the material.

3. The on-line EDXRD analyser according to claim 2 , wherein the detector collimator is situated in a close proximity to, or attached to, the energy-resolving X-ray detector.

4. The on-line EDXRD analyser according to claim 2 , where the collimated X-ray source comprises a sealed X-ray tube and a source collimator situated in a close proximity to, or attached to, the sealed X-ray tube, and where each of the source collimator and the detector collimator has a cylindrical-shaped aperture.

5. The on-line EDXRD analyser according to claim 2 , where the collimated X-ray source comprises a sealed X-ray tube and a source collimator situated in a close proximity to, or attached to, the sealed X-ray tube, and where each of the source collimator and the detector collimator has a conical-shaped aperture.

6. The on-line EDXRD analyser according to claim 2 , further comprising a source translation stage upon which is mounted the collimated X-ray source, and a detector translation stage upon which is mounted the energy-resolving X-ray detector and the detector collimator.

7. The on-line EDXRD analyser according to claim 6 , where the collimated X-ray source comprises a sealed X-ray tube and a source collimator situated in a close proximity to, or attached to, the sealed X-ray tube, and where each of the source translation stage and the detector translation stage comprises one or more micrometer-driven positioning devices to enable a fine adjustment of the source collimator and the detector collimator at least in a direction normal to the central axis between the collimated X-ray source and the energy-resolving X-ray detector.

8. The on-line EDXRD analyser according to claim 1 , where the collimated X-ray source comprises a sealed X-ray tube configured to operate at voltages between 15 and 150 kV or between 15 and 100 kV.

9. The on-line EDXRD analyser according to claim 8 , where the sealed X-ray tube comprises a low-power X-ray tube operable at an electron beam power of less than approximately 300 W.

10. The on-line EDXRD analyser according to claim 1 , further comprising:
a first hollow tube connecting the collimated X-ray source and a front end of the substantially X-ray transparent member to facilitate a passage of the diverging beam of polychromatic X-rays between the collimated X-ray source and the substantially X-ray transparent member; and
a second hollow tube connecting a second end of the substantially X-ray transparent member and the energy-resolving X-ray detector, to facilitate a passage of the portion of the diffracted beam of X-rays between the substantially X-ray transparent member and the energy-resolving X-ray detector.

11. The on-line EDXRD analyser according to claim 10 , where walls of each of the first hollow tube and the second hollow tube are substantially opaque to X-rays.

12. The on-line EDXRD analyser according to claim 10 , further comprising at least one of:
an X-ray window extending across an end of the first hollow tube proximate to the front end of the substantially X-ray transparent member; and
an X-ray window extending across an end of the second hollow tube proximate to the second end of the substantially X-ray transparent member.

13. The on-line EDXRD analyser according to claim 1 , where the substantially X-ray transparent member is configured in a form of a cylinder.

14. The on-line EDXRD analyser according to claim 1 , where the substantially X-ray transparent member is configured such that its radius varies along its length.

15. The on-line EDXRD analyser according to claim 1 , where the collimated X-ray source comprises a sealed X-ray tube and a source collimator situated in a close proximity to, or attached to, the sealed X-ray tube.

16. The on-line EDXRD analyser according to claim 1 , further comprising an X-ray beam divergence collimator positioned proximate a front end of the substantially X-ray transparent member.

17. The on-line EDXRD analyser according to claim 16 , wherein the X-ray beam divergence collimator is annular, having a central circular opening that has approximately a same diameter as the outer surface of the substantially X-ray transparent member at the front end of the substantially X-ray transparent member.

18. The on-line EDXRD analyser according to claim 1 , further comprising an X-ray beam convergence collimator positioned proximate a second end of the substantially X-ray transparent member.

19. The on-line EDXRD analyser according to claim 18 , wherein the X-ray beam convergence collimator is annular, having a central circular opening that has approximately a same diameter as the outer surface of the substantially X-ray transparent member at the second end of the substantially X-ray transparent member.

20. The on-line EDXRD analyser according to claim 1 , where the primary beam collimator comprises a machined plug of a material, whose outer surface is circularly symmetric with respect to the central axis.

21. The on-line EDXRD analyser according to claim 1 , where the primary beam collimator has a pluggable central circular shaped aperture, the pluggable central circular shaped aperture being aligned about the central axis between the collimated X-ray source and the energy-resolving X-ray detector.

22. The on-line EDXRD analyser according to claim 1 , further comprising a signal processor to process signals from the energy-resolving X-ray detector so as to determine spacings of atomic planes in crystals in the material, and/or proportions of different mineral species present in the material.

23. The on-line EDXRD analyser according to claim 1 , where the energy-resolving X-ray detector comprises a high-resolution semiconductor detector.

24. The on-line EDXRD analyser according to claim 23 , where the high-resolution semiconductor detector is one of a silicon drift detector, a Si-PiN diode detector, and a CdTe or HgI detector.

Assignees

• Commw Scient Ind Res Org

Inventors

• Tickner James Richard
• O'Dwyer Joel

Classifications

• G01N23/20091 Primary

  Measuring the energy-dispersion spectrum [EDS] of diffracted radiation · CPC title

• G21K1/025

  using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation · CPC title

• G01N2223/616

  earth materials · CPC title

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title

• G01N2223/50

  Detectors · CPC title