Low Power Neutron Generators

• US 20090146052A1
• Filed: 12/10/2007
• Published: 06/11/2009
• Est. Priority Date: 12/10/2007
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Groves, Joel L., Pfutzner, Harold
• Granted Patent: US 7,978,804 B2
• Time in Patent Office: Days
• US Class Current: 250/269.400
• CPC Class Codes: G01V 5/10 using neutron sources neutron generating tubes H05H5/00; neutron sources using isotopes G21G4/00
• CPC Class Codes: H05H 3/06 Generating neutron beams targets for producing nuclear reactions H05H6/00; neutron sources G21G4/02
• CPC Class Codes: Y02E 30/10 Nuclear fusion reactors

Abstract

A neutron generator and method of constructing the same. The generator includes a grid configured to produce an ionizable gas when heated by electrons impinging thereon. A cathode emits electrons to heat the grid and to collide with produced ionizable gas atoms to generate ions. Neutrons are generated from a collision of ions impinging on a target in the generator. A tool for subsurface use incorporating the neutron generator.

Claims

1. A neutron generator for subsurface use, comprising:

a grid configured to produce an ionizable gas when heated by electrons impinging thereon;

a cathode configured to emit electrons to heat the grid and collide with ionizable gas atoms to generate ions; and

a target to generate neutrons from a collision of ions impinging on the target.

2. The neutron generator of claim 1, wherein the grid is coated with a material that releases an ionizable gas when heated.

3. The neutron generator of claim 1, wherein the grid is positioned in a direct path to receive electrons emitted from the cathode.

4. The neutron generator of claim 1, wherein the cathode is configured to receive an adjustable current.

5. The neutron generator of claim 1, wherein the generator comprises a tube to house the grid, cathode, and target.

6. The neutron generator of claim 5, wherein the tube forms a sealed envelope to contain ionizable gas released by the grid.

7. The neutron generator of claim 5, further comprising Deuterium or Tritium gas disposed within the tube.

8. A neutron generator for subsurface use, comprising:

a tube forming a scaled envelope to contain a gas;

a grid disposed within the tube to produce an ionizable gas when heated by electrons impinging thereon;

a cathode disposed within the tube to emit electrons to heat the grid and collide with ionizable gas atoms to generate ions, and

a target disposed within the tube to generate neutrons from a collision of ions impinging on the target.

9. The neutron generator of claim 8, wherein the grid is coated with a material that releases an ionizable gas when heated.

10. The neutron generator of claim 8, wherein the grid is positioned in a direct path to receive electrons emitted from the cathode.

11. The neutron generator of claim 8, wherein the cathode is configured to receive an adjustable current.

12. The neutron generator of claim 8, wherein the tube comprises Deuterium or Tritium gas disposed therein.

13. A tool for subsurface use incorporating a neutron generator, the neutron generator comprising:

a tube forming a sealed envelope to contain a gas;

a grid disposed within the tube to produce an ionizable gas when heated by electrons impinging thereon;

a cathode disposed within the tube to emit electrons to heat the grid and collide with ionizable gas atoms to generate ions; and

a target disposed within the tube to generate neutrons from a collision of ions impinging on the target.

14. The tool of claim 13, wherein the grid is coated with a material that releases an ionizable gas when heated.

15. The tool of claim 13, wherein the grid is positioned in a direct path to receive electrons emitted from the cathode.

16. The tool of claim 13, further comprising an adjustable current supply for the cathode.

17. The tool of claim 16, further comprising a voltage supply for electrical components of the generator.

18. The tool of claim 13, wherein the tube comprises Deuterium or Tritium gas disposed therein.

19. A method for constructing a neutron generator for subsurface use, comprising disposing a cathode within a tube;

disposing a grid within the tube to produce an ionizable gas when heated by electrons impinging thereon;

configuring the cathode to emit electrons to strike the grid and to collide with ionizable gas atoms to generate ions, and

disposing a target within the tube to generate neutrons from a collision of ions impinging on the target.

20. The method of claim 19, wherein the grid is coated with a material that releases an ionizable gas when heated.

21. The method of claim 19, wherein the grid is positioned in a direct path to receive electrons emitted from the cathode.

22. The method of claim 19, further comprising coupling an adjustable current supply to the cathode.

23. The method of claim 22, further comprising coupling a voltage supply for electrical components of the generator.

24. The method of claim 19, further comprising disposing Deuterium or Tritium gas within the tube.

25. A method for constructing a neutron generator for subsurface use, comprising:

disposing a cathode within a tube configured for mounting on a tool for subsurface disposal, the tube forming a sealed envelope to contain a gas;

disposing a grid within the tube to receive electrons emitted from the cathode, the grid configured to produce an ionizable gas when heated by electrons impinging thereon;

configuring the cathode to emit electrons to collide with ionizable gas atoms to generate ions; and

disposing a target within the tube to generate neutrons from a collision of ions impinging on the target.