Scanning line detector for two-dimensional x-ray diffractometer
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.
1. 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 individual detection elements arranged in an elongate shape to form a detection area that extends substantially linearly along a longitudinal dimension of the detector, wherein the x-ray detector moves along a detection circle centered about an axis that passes through the sample location perpendicular to the diffractometer plane so as to collect x-ray diffraction data across a multidimensional space; and
a mechanism that generates a two-dimensional x-ray diffraction pattern from collected x-ray diffraction data.
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 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 the longitudinal dimension of the 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 plane containing the detection circle.
11. A system according to claim 1 wherein a distance between the detector and the sample may be changed to change an angular resolution of the detector.
12. An x-ray diffraction analysis system according to claim 1 wherein the two-dimensional x-ray diffraction pattern comprises Debye rings.
13. A method of performing an x-ray diffraction analysis of a sample located at a sample location that intersects a diffractometer plane, 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 along a detection circle centered about an axis that passes through the sample location perpendicular to the diffractometer plane so as to collect x-ray diffraction data across a multidimensional space; and
generating a two-dimensional x-ray diffraction pattern from collected x-ray diffraction data.
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 comprises moving the detector along a path that is parallel to the diffractometer plane.
16. A method according to claim 15 wherein the 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 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 plane containing the detection circle.
22. A method according to claim 13 further comprising changing a distance between the detector and the sample to change an angular resolution of the detector.
23. A method according to claim 13 wherein the two-dimensional x-ray diffraction pattern comprises Debye rings.
24. 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; and
an x-ray detector having individual detection elements arranged in an elongate shape to form a detection area that extends in a substantially straight line along a longitudinal dimension of the detector, wherein the x-ray detector moves along a detection circle that is parallel to the diffractometer plane and that is centered about an axis that passes through the sample location, so as to collect x-ray diffraction data across a multidimensional space; and
a mechanism that generates a two-dimensional x-ray diffraction pattern from collected x-ray diffraction data.
25. An x-ray diffraction analysis system according to claim 24 wherein the two-dimensional x-ray diffraction pattern comprises Debye rings.