DARK FIELD TENSOR TOMOGRAPHY METHOD, SPECIMEN HOLDER AND DEVICE

• US 20190331616A1
• Filed: 11/28/2017
• Published: 10/31/2019
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Technische Universitat Munchen
• Original Assignee: Technische Universitat Munchen
• Inventors: Schaff, Florian, Pfeiffer, Franz
• Granted Patent: US 11,143,603 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 2223/045 combination of at least 2 measurements (transmission and scatter)
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/041 Phase-contrast imaging, e.g. using grating interferometers
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01N 23/20025 Sample holders or supports therefor
• CPC Class Codes: G01N 23/201 by measuring small-angle scattering

Abstract

The invention relates to an X-ray CT method and in particular a registration-based dark-field tensor tomography method for testing a sample (60) by means of X-rays, with which method a sample (60) is consecutively scanned by means of X-rays in at least two fixed orientations differing from one another while rotating about a fixed rotation axis, in every orientation of the sample (60) on the basis of dark-field signals a plurality of scatter data sets is recorded, and the scatter data sets for different orientations are matched to one another by registration and combined into a common scatter data set reflecting a possible angular dependence of the scatter present due to the sample (60).

Claims

1. An X-ray CT method and in particular a registration-based dark-field tensor tomography method for testing a sample (60) by means of X-rays, wherein

a sample (60) is consecutively scanned by means of X-rays in at least two fixed orientations differing from one another while rotating about a fixed rotation axis,

in every orientation of the sample (60) on the basis of dark-field signals a plurality of scatter data sets is recorded, and

the scatter data sets for different orientations are matched to one another by registration and combined into a common scatter data set reflecting a possible angular dependence of the scatter present due to the sample (60).

2. The method in accordance with claim 1, wherein a respective orientation of the sample (60) is defined by an orientation of a fixed rotation axis (81) of the sample (60).

3. The method in accordance with claim 1 or 2, wherein the sample (60) is scanned for at least three different orientations of the rotation axis (81) in order to generate scatter data sets, with these three orientations of the rotation axis (81) being in particular perpendicular or substantially perpendicular to one another in pairs, in particular enclosing an angle of at least 70°

, preferably of at least 80°

, more preferably of at least 85°

.

4. The method in accordance with one of the preceding claims, wherein for generating scatter data sets, the sample (60) is scanned for four different orientations of the rotation axis (81).

5. The method in accordance with one of the preceding claims, wherein a respective rotation axis (81) is aligned perpendicular or substantially perpendicular to an orientation of the sample (60) or to identically oriented first, second and third grating elements (31, 32, 33) of a grating arrangement (30) between a radiation source (20) and a detector arrangement (40) in the ray path (26) of a used grating-based interferometer arrangement of an X-ray CT device (1) forming the basis.

6. The method in accordance with one of the preceding claims,

wherein for mounting the sample (60) and for setting the orientation, in particular of a respective rotation axis (81), a sample holder (10) is used which has a sample holder body (11) designed to receive the sample (60) in its interior (12) indirectly or directly on an inner side (11-1) of the sample holder hollow body (11), in particular detachably, and connected or connectable non-rotatably to the sample holder body (11),

wherein the sample holder (10) is designed in particular in accordance with one of the claims 7 to 13.

7. A sample holder (10) for an X-ray CT device (1) and in particular for a registration-based dark-field tensor tomography device for mounting a sample (60) to be tested by means of an X-ray CT method and/or for being used in a method in accordance with one of the claims 1 to 6, comprising:

a sample holder body (11) designed to receive a respective sample (60) in its interior (12) indirectly or directly on an inner side (11-1) of the sample holder hollow body (11), in particular detachably, and connected or connectable non-rotatably to the sample holder body (11).

8. The sample holder (10) in accordance with claim 7, wherein the sample holder body (11) is designed partially or completely as a hollow body (11-1), in particular with edge elements (13) and/or surface elements (14) forming the sample holder body (11).

9. The sample holder (10) in accordance with claim 7 or 8, wherein the sample holder body (11) is designed partially or completely as a frame structure (11-2), in particular with edge elements (13) forming the sample holder body (11).

10. The sample holder (10) in accordance with one of the claims 7 to 9, wherein the sample holder body (11) has a shape from the group of shapes formed by the shape of a hollow sphere, a hollow ellipsoid, an Archimedean solid and in particular a cube, cuboid, icosahedron or cuboctahedron, in particular in the manner of an edge or grating model.

11. The sample holder (10) in accordance with one of the claims 7 to 10, wherein the sample holder body (11) has a fastening arrangement (70), preferably in its interior (12), for—

in particular detachable—

fastening of a sample (60) to be tested on an inner side (11-1) of the sample holder hollow body (11), preferably with one or more fastening means (71), in the form of thread or rod structures and/or of adhesive points.

12. The sample holder (10) in accordance with one of the claims 7 to 11, if related to at least one of the claim 8 or 9, comprising:

a respective edge element (13) and/or a respective surface element (14) being formed from a material which has uniform optical properties for X-rays to be used and in particular is uniformly transparent.

13. The sample holder (10) in accordance with one of the claims 7 to 12, comprising:

a rotation device (80) with a drivable rotation axis (81)—

in particular controllable—

on which or to which the sample holder body (11) is coupled or couplable non-rotatably.

14. An X-ray CT device (1) and in particular a registration-based dark-field tensor tomography device for testing a sample (60) by means of an X-ray CT method, and in particular by means of a registration-based dark-field tensor tomography method and/or for being used in a method in accordance with one of the claims 1 to 6,

wherein a sample holder (10) in accordance with one of the claims 7 to 13 is designed for receiving a sample (60) to be tested.

15. The X-ray CT device (1) in accordance with claim 14, wherein the X-ray CT device (1) is designed as a grating-based interferometer arrangement and with a controllable radiation source (20) for generating and emitting primary X-rays (21) and with a detector arrangement (40) at a spatial distance from the radiation source (20) for detection of X-rays (25) emitted by the radiation source (20) via a ray path (26),

wherein a grating arrangement (30) with first, second and third grating elements (31, 32, 33) aligned to one another in the ray path (26) is provided between the radiation source (20) and the detector arrangement (40), and

wherein the sample holder (10) is arranged in the ray path (26) between a first grating element (31) on the radiation source side and a second grating element (32) on the detector side.