Scanning line detector for two-dimensional x-ray diffractometer

• US 20060093090A1
• Filed: 10/29/2004
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Bruker AXS Incorporated (Bruker Corporation)
• Original Assignee: Bruker AXS Incorporated (Bruker Corporation)
• Inventors: He, Bob Baoping
• Granted Patent: US 7,190,762 B2
• Time in Patent Office: Days
• US Class Current: 378/70
• CPC Class Codes: G01N 2223/5015 linear array
• CPC Class Codes: G01N 23/207 Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions

Abstract

A scanning line detector according to the present invention uses a detector with a linear arrangement of detection elements that is moved along a range of diffracted x-ray directions to collect data across a multidimensional detection area. The scanning line detector allows for the simulation of a two-dimensional detector system without the need for a two-dimensional detector. The detector may follow a desired path to simulate a desired shape, such as a cylinder. A slit may be included to limit the detector line width, and a scatter shield may be used to minimize noise from air-scattered x-rays. The detector may also use a specially designed monochromator for conditioning the diffracted x-rays. The detector may be rotatable about an axis parallel to a direction along which x-rays are diffracted, allowing it to be used in different orientations.

Claims

1. An x-ray diffraction analysis system for analyzing a sample located at a sample location, the system comprising:

a source of x-ray energy directed toward the sample;

an x-ray detector having an elongate shape such that individual detection elements of the detector are arranged substantially linearly, wherein the x-ray detector is movable substantially perpendicularly to directions along which x-ray energy is diffracted by the sample so as to collect x-ray diffraction data across a multidimensional space.

2. A system according to claim 1 wherein the detection elements of the detector are arranged in a substantially straight line.

3. A system according to claim 1 wherein the sample intersects a diffractometer plane, and wherein the detector follows a path that is parallel to the diffractometer plane.

4. A system according to claim 3 wherein the line detector is movable in a direction perpendicular to the diffractometer plane while following the path parallel to the diffractometer plane.

5. A system according to claim 1 further comprising a slit positioned in front of the detection elements of the detector that limits the detection line width.

6. A system according to claim 1 further comprising a scatter shield that moves with the detector and that shields the detector from scattered x-ray radiation along directions outside of an selected x-ray diffraction range.

7. A system according to claim 1 further comprising a monochromator that redirects diffracted x-ray energy toward the detector, the monochromator limiting the redirected x-ray energy to a predetermined wavelength range.

8. A system according to claim 7 wherein the monochromator comprises a multilayer mirror

9. A system according to claim 8 wherein the multilayer mirror has a layer d-spacing that varies along a direction parallel to a longitudinal dimension of the line detector.

10. A system according to claim 1 wherein the detector may be positioned in any of a plurality of rotational orientations about an axis parallel to a direction along which x-ray energy is diffracted.

11. A system according to claim 1 wherein a distance between the detector and the sample may be changed to change the angular resolution.

12. An x-ray diffraction analysis system for analyzing a sample located at a sample location that intersects a diffractometer plane, the system comprising:

a source of x-ray energy directed toward the sample;

an x-ray detector having an elongate shape such that individual detection elements of the detector are arranged along a substantially straight line, wherein the x-ray detector is movable substantially perpendicularly to directions along which x-ray energy is diffracted by the sample, and parallel to the diffractometer plane, so as to collect x-ray diffraction data across a multidimensional space.

13. A method of performing an x-ray diffraction analysis of a sample located at a sample location, the method comprising:

directing x-ray energy toward the sample with an x-ray source;

detecting x-ray energy diffracted from the sample with an x-ray detector having an elongate shape such that individual detection elements of the detector are arranged substantially linearly; and

moving the x-ray detector substantially perpendicularly to directions along which x-ray energy is diffracted by the sample so as to collect x-ray diffraction data across a multidimensional space.

14. A method according to claim 13 wherein the detection elements of the detector are arranged in a substantially straight line.

15. A method according to claim 13 wherein the sample intersects a diffractometer plane, and wherein moving the detector comprising moving the detector along a path that is parallel to the diffractometer plane.

16. A method according to claim 15 wherein the line detector is movable in a direction perpendicular to the diffractometer plane while following the path parallel to the diffractometer plane.

17. A method according to claim 13 further comprising limiting the detection line width with a slit positioned in front of the detection elements of the detector.

18. A method according to claim 13 further comprising shielding the detector from scattered x-ray radiation along directions outside of an anticipated x-ray diffraction range with a scatter shield that moves with the detector.

19. A method according to claim 13 further comprising redirecting diffracted x-ray energy toward the detector with a monochromator that limits the redirected x-ray energy to a predetermined wavelength range.

20. A method according to claim 19 wherein the multilayer mirror has a layer d-spacing that varies along a direction parallel to a longitudinal dimension of the line detector.

21. A method according to claim 13 wherein the detector may be positioned in any of a plurality of rotational orientations about an axis parallel to a direction along which x-ray energy is diffracted.

22. A method according to claim 13 further comprising changing a distance between the detector and the sample to change the angular resolution.