Segmented scintillation antineutrino detector

Patent metadata

Field	Value
Publication number	US-9645258-B1
Application number	US-201414553792-A
Country	US
Kind code	B1
Filing date	Nov 25, 2014
Priority date	Nov 25, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

The various technologies presented herein relate to incorporating a wavelength-shifting material in a scintillator to facilitate absorption of a first electromagnetic particle (e.g., a first photon) having a first wavelength and subsequent generation and emission of a second electromagnetic particle (e.g., a second photon) having a second wavelength. The second electromagnetic particle can be emitted isotropically, with a high probability that the direction of emission of the second electromagnetic particle is disparate to the direction of travel of the first electromagnetic particle (and according angle of incidence). Isotropic emission of the second electromagnetic particle enables the second electromagnetic particle to be retained in the scintillator owing to internal reflection. Accordingly, longer length scintillators can be constructed, and accordingly, the scintillator array has a greater area (and volume) over which to detect electromagnetic particles (e.g., antineutrinos) being emitted from a nuclear reaction.

First claim

What is claimed is:

1. An antineutrino detector, comprising:
a scintillator having a first end, a second end, and an external surface that extends between the first end and the second end, wherein the scintillator of the antineutrino detector includes a wavelength shifting material;
a screen positioned adjacent the external surface, the screen has a layer of lithium doped scintillator attached thereto; and
a photomultiplier tube positioned adjacent the first end of the scintillator, wherein:
the scintillator is configured to emit a neutron in response to an antineutrino interacting with a proton in the scintillator;
the lithium doped scintillator is configured to emit a first photon in response to the neutron being incident upon the lithium doped scintillator, wherein the first photon has a wavelength;
the wavelength shifting material of the scintillator is configured to absorb the first photon and emit a second photon responsive to absorbing the first photon, wherein the second photon has a second wavelength that is longer than the first wavelength; and
the photomultiplier tube is configured to generate a signal responsive to detecting the second photon, wherein the signal is indicative of the antineutrino interacting with the proton in the scintillator.

2. The antineutrino detector of claim 1 , wherein the second photon is emitted from the wavelength shifting material isotropically, wherein a direction of emission of the second photon is disparate to an angle of incidence of the first photon with respect to the external surface of the scintillator.

3. The antineutrino detector of claim 1 , wherein the screen surrounds the scintillator along its length.

4. The antineutrino detector of claim 1 , further comprising a second photomultiplier tube positioned adjacent to the second end of the scintillator.

5. The antineutrino detector of claim 1 , further comprising:
a second scintillator located adjacent to the scintillator, the scintillator and the second scintillator separated by the screen.

6. The antineutrino detector of claim 1 , wherein the scintillator has a length of 2 meters.

7. The antineutrino detector of claim 1 , wherein the first wavelength is between 440 and 500 nm.

8. The antineutrino detector of claim 1 , wherein an air gap exists between the screen and the scintillator.

9. A method for detecting an antineutrino particle, comprising:
receiving the antineutrino particle at a scintillator material, the scintillator material comprises a proton, the antineutrino and the proton interacting to initiate an inverse beta-decay process causing a neutron and a positron to be emitted;
capturing the neutron at a screen located adjacent to the scintillator material, wherein the screen comprises a layer of material configured to capture the neutron and generate a first photon, wherein the first photon is emitted into the scintillator material;
converting the first photon to a second photon, wherein the first photon has a first wavelength and the second photon has a second wavelength, the second wavelength is longer than the first wavelength, and the converting is performed by a dopant in the scintillator material;
detecting the second photon, the second photon being detected by a photomultiplier tube attached to the scintillator material; and
based upon detecting the second photon, generating an indication of the antineutrino being received at the scintillator material.

10. The method of claim 9 , wherein the second photon is emitted isotropically by the dopant, wherein a direction of emission of the second photon is disparate to direction of travel of the first photon.

11. The method of claim 9 , wherein the positron annihilates to form at least one gamma ray, wherein the gamma ray is subsequently absorbed by the scintillator material to form a third photon, wherein the third photon interacts with the dopant to form a fourth photon.

12. The method of claim 11 , further comprising detecting the fourth photon at the photomultiplier tube, wherein the indication of the antineutrino being received at the scintillator material is further based upon the fourth photon being detected.

13. The method of claim 9 , further comprising converting the neutron to a particle, and further converting the particle to form the first photon, whereby the converting of the neutron to the particle and the converting of the particle to the first photon occurring in the layer of material of the screen.

14. The method of claim 13 , wherein the particle is one of an alpha particle or tritium.

15. An antineutrino detector, comprising:
a scintillator, wherein the scintillator is a cuboid, and the scintillator comprises an organic material comprising a proton, interaction of the proton with an antineutrino incident thereon initiates an inverse beta-decay process resulting in generation of a neutron and a positron;
a wavelength-shifting compound, the wavelength-shifting compound is configured to:
absorb a first photon having a first wavelength and direction of travel; and
responsive to absorbing the first photon, emit a second photon having a second wavelength that is longer than the first wavelength, wherein the second photon is emitted in a direction disparate to the direction of travel of the first photon; and

a screen, wherein the screen is located adjacent to a long side of the scintillator, the screen includes a layer, wherein the layer is configured to capture the neutron and in response to capturing the neutron, emit the first photon.

16. The antineutrino detector of claim 15 , wherein the layer includes a lithium-doped scintillator.

17. The antineutrino detector of claim 15 , further comprising a photomultiplier tube configured to detect the second photon.

18. The antineutrino detector of claim 17 , further comprising a second scintillator, wherein the second scintillator is located alongside the scintillator, the second scintillator has a second photomultiplier tube attached thereto, the scintillator and the second scintillator are separated by the screen.

19. The antineutrino detector of claim 15 , further comprising a pair of photomultiplier tubes positioned on opposite ends of the cuboid.

20. The antineutrino detector of claim 15 , wherein the first wavelength is between 440 and 500 nm.

Assignees

• Sandia Corp

Inventors

• Reyna David

Classifications

• G21C17/00

  Monitoring; Testing (measuring in general G01); {Maintaining} · CPC title

• G01T1/20 Primary

  with scintillation detectors · CPC title

• G01T1/208

  Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title

• G21C1/00

  Reactor types · CPC title