Two-Dimensional Detection System for Neutron Radiation in the Field of Neutron Scattering Spectrometry

• US 20080210880A1
• Filed: 03/09/2006
• Published: 09/04/2008
• Est. Priority Date: 03/10/2005
• Status: Abandoned Application

• Current Assignee: Centre National De La Recherche Scientifique, Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Baroni, Patrick Francois, Noirez, Laurence Marie
• Application Number:
  US11/908,096
• Publication Number:
  US 20080210880A1
• Time in Patent Office: Days
• US Class Current: 250/390.11
• CPC Class Codes: G01N 23/2073 using neutron detectors neutron spectrometry G01T3/00
• CPC Class Codes: G01T 3/00 Measuring neutron radiation G01T5/00 takes precedence
• CPC Class Codes: G01T 3/001 Spectrometry
• CPC Class Codes: G01T 3/06 with scintillation detectors
• CPC Class Codes: G01T 3/065 Spectrometry

Abstract

A two-dimensional detection system for neutron radiation is disclosed. The detection system includes a means (1) for emitting a neutron beam (10), a support means (2) adapted for receiving a sample (3), a photoemission means (5) adapted for being activated by a neutron radiation, and a cooled low light level charge-coupled detection device (7). The emission means (1) emits a monochromatic neutron beam (10). The system further includes a filter means (4), the filter means (4) being located between the support means (2) and the photoemission means (5) and being adapted for trapping at least a substantial part of the monochromatic neutron beam transmitted (12) by the sample (3), and an amplification means (6) located upstream the charge-coupled detection device (7) and coupled with the charge-coupled detection device (7).

Claims

1. Two-dimensional detection system for neutron radiation comprising a means for emitting a neutron beam, a support means adapted for receiving a sample, a photoemission means adapted for being activated by a neutron radiation, a cooled low light level charge-coupled detection device, wherein the emission means emits a monochromatic neutron beam and in that the system further comprises:

a filter means, the filter means being located between the support means and the photoemission means and being adapted for trapping at least a substantial part of the monochromatic neutron beam transmitted by the sample; and

an amplification means located upstream the charge-coupled detection device and coupled with the charge-coupled detection device.

2. Two-dimensional detection system for neutron radiation according to claim 1, wherein the filter means traps the entire monochromatic neutron beam transmitted by the sample.

3. Two-dimensional detection system for neutron radiation according to claim 1, wherein the photoemission means emits alpha radiation originating from a single nuclear reaction.

4. Two-dimensional detection system for neutron radiation according to claim 3, wherein the photoemission means is a lithium-based scintillator.

5. Two-dimensional detection system for neutron radiation according to claim 4, wherein the lithium-based scintillator is a composite material based on lithium sulphide.

6. Two-dimensional detection system for neutron radiation according to claim 4, wherein the lithium-based scintillator is a composite material based on lithium fluoride.

7. Two-dimensional detection system for neutron radiation according claim 1, wherein the photoemission means is in the form of a plate with a length of between 5 and 100 cm, a width of between 5 and 100 cm and a thickness of less than or equal to 1.2 mm.

8. Two-dimensional detection system for neutron radiation according to claim 3, wherein the photoemission means is plane.

9. Two-dimensional detection system for neutron radiation according to claim 3, wherein the photoemission means is curved, defined by a portion of cylinder delimited by a plane with dimensions varying from 5 to 100 cm in length and in width.

10. Two-dimensional detection system for neutron radiation according to claim 3, wherein the photoemission means is curved, defined by a portion of sphere.

11. Two-dimensional detection system for neutron radiation according to claim 3, wherein the photoemission means is lined with a surface opaque to light and transparent to neutron radiation, and located on the inlet of the photoemission means.

12. Two-dimensional detection system for neutron radiation according to claim 11, wherein the opaque surface is formed from a rigid material adapted for holding the photoemission means in place.

13. Two-dimensional detection system for neutron radiation according to claim 11, wherein the opaque surface is an aluminum plate.

14. Two-dimensional detection system for neutron radiation according to claim 1, wherein the charge-coupled detection device enables coding on at least 12 bits.

15. Two-dimensional detection system for neutron radiation according to claim 14, wherein the charge-coupled detection device enables coding on 16 bits.

16. Two-dimensional detection system for neutron radiation according to claim 1, wherein the charge-coupled detection device is a camera adapted for variable pause times.

17. Two-dimensional detection system for neutron radiation according to claim 1, wherein the photoemission means, the amplification means and the charge-coupled detection device are enclosed in a box designed such that no light radiation other than that emitted by the photoemission means can penetrate inside.

18. Two-dimensional detection system for neutron radiation according to claim 17, wherein the photoemission means and the charge-coupled detection device coupled with the amplification means respectively form the inlet end and outlet end of the box.

19. Two-dimensional detection system for neutron radiation according to claim 18, wherein the system further comprises a protection means capable of reducing the influence of parasite radiation between support means for the sample and the photoemission means.

20. Two-dimensional detection system for neutron radiation according to claim 19, wherein the protection means is a conical or pyramid shaped element, having the photoemission means as its base and being located between the support means for the sample and the photoemission means.

21. Two-dimensional detection system for neutron radiation according to claim 19, wherein the protection means is a casing comprising a cylindrical part and a tapered end part, and surrounding the box.

22. Two-dimensional detection system for neutron radiation according to claim 19, the protection means includes sidewalls adapted for absorbing parasite radiation not originating from the sample.

23. Two-dimensional detection system for neutron radiation according to claim 19, wherein the protection means contains an inert gas or a primary vacuum.

24. Two-dimensional detection system for neutron radiation according to claim 23, wherein the inert gas is helium.

25. Two-dimensional detection system for neutron radiation according to claim 23, wherein the inert gas is argon.

26. Two-dimensional detection system for neutron radiation according to claim 23, wherein the inert gas is nitrogen.

27. Two-dimensional detection system for neutron radiation according to claim 17, wherein the box comprises inside walls adapted for absorbing neutron and gamma radiation.

28. Two-dimensional detection system for neutron radiation according to claim 1, wherein the system further comprises a mirror adapted for reflecting only light radiation emitted by the photoemission means towards the amplification means.

29. Two-dimensional detection system for neutron radiation according to claim 28, wherein the mirror is made from aluminized quartz and is less than or equal to 10 mm thick.

30. Two-dimensional detection system for neutron radiation according to claim 28, wherein the mirror is plane.

31. Two-dimensional detection system for neutron radiation according to claim 28, wherein the mirror is curved.

32. Two-dimensional detection system for neutron radiation according to claim 1, wherein the system further comprises a means for absorbing neutron and gamma radiation, this absorption means being arranged at the outlet of the photoemission means.

33. Two-dimensional detection system for neutron radiation according to claim 1, wherein the amplification means and the charge-coupled detection device are surrounded by a shield for stopping gamma radiation.

34. Two-dimensional detection system for neutron radiation according to claim 33, wherein the shield is a metal with a thickness and a density such that the product of the thickness and the density is greater than or equal to 34.

35. Two-dimensional detection system for neutron radiation according to claim 33, wherein the shield is made of tungsten with a thickness of about 2 cm.

36. Two-dimensional detection system for neutron radiation according to claim 1, wherein the system further comprises a collimation device arranged between the emission means and the support means, and outputting an output neutron beam with a diameter of between 0.5 and 15 mm.

37. Two-dimensional detection method for neutron radiation comprising the steps of:

emitting a neutron beam towards a sample,

transforming the neutron beam output from the sample into photons,

detecting the photons emitted by a cooled low light level charge transfer detection device,

the method being characterized in that it further comprises the steps consisting of;

transforming the neutron beam emitted towards the sample into a monochromatic neutron beam,

filtering the neutron beam output from the sample so as to trap at least a substantial part of the monochromatic neutron beam transmitted by the sample,

amplifying the photon radiation upstream the cooled low light level charge transfer detection device.