Deuterium-deuterium neutron generators

Patent metadata

Field	Value
Publication number	US-10182491-B2
Application number	US-201314432660-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Dec 30, 2013
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

Various embodiments include apparatus and methods of using the apparatus having a neutron generator. The neutron generator can include a neutron generator tube having a cylindrical inner surface that bounds a cylindrical cavity, a field ionization array cylindrically distributed on the cylindrical inner surface, and a target rod positioned in the cylindrical cavity. Additional apparatus, systems, and methods are disclosed.

First claim

What is claimed is:

1. An apparatus comprising:
a neutron generator tube having a cylindrical inner surface that bounds a cylindrical cavity;
a deuterium source that provides deuterium within the cylindrical cavity;
a target rod positioned in the cylindrical cavity, wherein the target rod comprises a rod material and a first material layer disposed on the rod material, wherein the first material layer has a thermal conductivity less than copper, and wherein the target rod has a second material layer disposed on the first material layer; and
a field ionization array cylindrically distributed around the cylindrical inner surface.

2. The apparatus of claim 1 , wherein the target rod is positioned along an axis of symmetry of the neutron generator tube at a center of the cylindrical cavity.

3. The apparatus of claim 1 , wherein the field ionization array comprises a bundle of nano-emitters.

4. The apparatus of claim 3 , wherein the bundle of nano-emitters comprises at least one of tungsten nano-tips and carbon nano-fibers.

5. The apparatus of claim 1 , wherein the first material layer include one or more transition metals.

6. The apparatus of claim 5 , wherein the one or more transition metals include one or more of titanium and erbium.

7. The apparatus of claim 1 , wherein the neutron generator tube is disposed in a housing configured for a wireline deployment.

8. The apparatus of claim 1 , wherein the neutron generator tube is disposed in a housing configured for a logging-while-drilling deployment.

9. The apparatus of claim 1 , further comprising a suppressor grid, wherein the suppressor grid is positioned concentrically around the target rod.

10. The apparatus of claim 1 , further comprising an electric insulator disposed between the deuterium source and the target rod.

11. A method comprising:
generating neutrons into a formation around a borehole using an apparatus comprising,
a neutron generator tube comprising a cylindrical inner surface that bounds a cylindrical cavity,
a deuterium source that provides deuterium within the cylindrical cavity,
a target rod positioned in the cylindrical cavity, wherein the target rod comprises a rod material and a first material layer disposed on the rod material, and wherein the target rod has a second material layer disposed on the first material layer, and
a field ionization array cylindrically distributed around the cylindrical inner surface; collecting signals in response to generating the neutrons; and

determining properties of the formation or the borehole based on the collected signals.

12. The method of claim 11 , wherein using the neutron generator tube includes using a bundle of nano-emitters as part of the field ionization array.

13. The method of claim 11 , further comprising disposing the neutron generator tube in a wireline housing.

14. The method of claim 11 , further comprising disposing the neutron generator tube in a logging-while-drilling housing.

15. The method of claim 11 , wherein generating neutrons comprises applying a voltage pulse to a field ionization electrode attached to the field ionization array, wherein the voltage pulse is less than 120 kilovolts, and wherein the voltage pulse produces a monatomic deuterium ratio greater than or equal to 50%.

16. The method of claim 11 , wherein generating neutrons comprises applying a turn-on/turn-off time delay of the field ionization array that is less than 1 microsecond.

17. An apparatus comprising:
a neutron generator tube having a cylindrical inner surface that bounds a cylindrical cavity;
a deuterium source that provides deuterium within the cylindrical cavity;
a target rod positioned in the cylindrical cavity, wherein the target rod comprises a rod material, a first material layer disposed on the rod material, and a second material layer disposed on the first material layer; and
a field ionization array cylindrically distributed around the cylindrical inner surface.

18. The apparatus of claim 17 , wherein the target rod is positioned along an axis of symmetry of the neutron generator tube at a center of the cylindrical cavity.

19. The apparatus of claim 17 , wherein the field ionization array comprises a bundle of nano-emitters.

20. The apparatus of claim 17 , wherein the first material layer comprises one or more transition metals.

Assignees

• Halliburton Energy Services Inc

Inventors

• Navarro-Sorroche Juan
• Guo Weijun

Classifications

• H05H3/06 Primary

  Generating neutron beams (targets for producing nuclear reactions H05H6/00; neutron sources G21G4/02) · CPC title

• G21B1/19

  Targets for producing thermonuclear fusion reactions, e.g. pellets for irradiation by laser or charged particle beams · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title

• G21G4/02

  Neutron sources · CPC title

• E21B47/00

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title