X-ray quanta measuring device including diaphragm for producing conical radiation beam on object being measured

• US 5,008,911 A
• Filed: 09/22/1989
• Issued: 04/16/1991
• Est. Priority Date: 09/22/1988
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Harding, Geoffrey
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): CHU, KIM KWOK
• Application Number:
  US07/411,357
• Time in Patent Office: 571 Days
• Field of Search: 378/147, 378/149, 378/86, 378/88, 378/89
• US Class Current: 378/86
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: G01N 23/20091 Measuring the energy-dispersion spectrum [EDS] of diffracted radiation

Abstract

A device for measuring the pulse transfer of X-ray quanta which are elastically scattered in an examination zone, includes an X-ray source which is arranged on one side of the examination zone, a detector which is situated on the other side of the examination zone and which measures the energy of the X-ray quanta, and a rotationally-symmetrical diaphragm device which is arranged between the detector and the X-ray source. In a device of this kind a comparatively accurate determination of the pulse transfer is also possible for thick objects, because the diaphragm device is constructed so that the X-ray quanta emitted by the X-ray beam source are transmitted to the examination zone only on the envelope of a cone.

Claims

1. A device for measuring the pulse transfer spectrum of X-ray quanta which are elastically scattered in an examination zone of an X-ray system comprising a polychromatic x-ray source on one side of the examination zone, said measuring device comprising:

a detector on the other side of the zone for measuring the energy of the X-ray quanta; and

two apertured diaphragms which have a common symmetry axis and which transmit scattered radiation to the detector only within a given scattering angle range, a first diaphragm being between the examination zone and the X-ray source and a second diaphragm between the examination zone and the detector, the first diaphragm being constructed so that the X-rays transmitted therethrough form a conical envelope of a primary radiation cone, the second diaphragm being constructed so that scattered radiation produced in the examination zone is incident on the detector in an annular symmetrical fashion with respect to said axis of symmetry.

2. A device as claimed in claim 1, wherein the second diaphragm is constructed so that it defines a scattered radiation cone which is tapered in the direction from the examination zone towards the detector device.

3. A device as claimed in claim 1, wherein the second diaphragm is arranged at a distance from the examination zone as well as at a distance from the detector and whose aperture coincides with the symmetry axis.

4. A device as claimed in claim 1, wherein the second diaphragm comprises a plurality of mutually enclosing cylindrical collimator members which are concentric with the symmetry axis of the primary radiation cone.

5. A device as claimed in claim 4, wherein the detector comprises a plurality of concentric annular detectors.

6. A device as claimed in claim 5, wherein the diameters of the collimator members and the detectors are adapted to one another so that the scattered radiation passing between two collimator members is detected by one detector.

7. A device as claimed in claim 1, wherein the first diaphragm comprises an aperture on the symmetry axis, on the symmetry axis on the other side of the examination zone there being provided a further detector for measuring the transmitted radiation.

8. A device as claimed in claim 7, wherein the further detector measures the scattered radiation in an energy-resolution fashion.

9. A device as claimed in claim 7, wherein the further detector comprises a detector crystal in conjunction with the annular detectors.

10. A device as claimed in claim 3, wherein the distance between the detector and the examination zone is substantially larger than the distance between the X-ray source and the examination zone.

11. A device as claimed in claim 4, wherein between neighbouring collimator members baffles are arranged in planes which intersect at the symmetry axis.

12. A device as claimed in claim 3, wherein the detector comprises a plurality of concentric annular detectors.

13. A device as claimed in claim 2, wherein the first diaphragm comprises an aperture on the symmetry axis, on the symmetry axis on the other side of the examination zone there being provided a further detector for measuring the transmitted radiation.

14. A device as claimed in claim 4, wherein the distance between the detector and the examination zone is substantially larger than the distance between the X-ray source and the examination zone.

15. The device of claim 1 wherein each said diaphragms comprises at least one annular ring-like aperture concentric with said axis.

16. The device of claim 15 wherein the diaphragms have a further central aperture for passing a relatively narrow beam of said radiation within said cone.

17. The device of claim 1 wherein the first diaphragm has a ring-like annular aperture.