NANO-TIPS BASED GAS IONIZATION CHAMBER FOR NEUTRON DETECTION

• US 20120049054A1
• Filed: 08/31/2010
• Published: 03/01/2012
• Est. Priority Date: 08/31/2010
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Zhou, Zilu, Berheide, Markus, Chen, Felix, Roscoe, Bradley A., Wong, Joyce, Luling, Martin G., Philip, Olivier
• Granted Patent: US 8,319,175 B2
• Time in Patent Office: Days
• US Class Current: 250/265
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01T 1/16 Measuring radiation intensity G01T1/29 takes precedence ; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008
• CPC Class Codes: G01T 1/18 with counting-tube arrangements, e.g. with Geiger counters tubes H01J47/08; with alarm provision G01T7/125
• CPC Class Codes: G01T 3/008 using an ionisation chamber filled with a gas, liquid or solid, e.g. frozen liquid, dielectric G01T3/006 takes precedence

Abstract

Methods and devices relating to a radiation detector comprising of a gas chamber having a cathode plate and a substrate separated by a gap. An array of nano-tips deposited on the substrate that forms an anode structure for electron charge collection. An external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions and each region includes an electric field near each nano-tip of the array of the nano-tips that results in initiating a radiation induced controlled discharge of electrons and ions from at least one gas or at least one gas mixture. Finally, the plurality of regions include multiple generated electric fields near tips of the array of nano-tips such as CNTs, that communicatively create a conductive path between the cathode plate and the substrate, the radiation detector is capable of determining at least one radiation property.

Claims

1. A radiation detector, the radiation detector comprising:

one or more gas chamber, each gas chamber includes a cathode plate and a substrate separated by a gap;

an array of nano-tips deposited on a portion of the substrate forms an anode structure for electron charge collection;

an external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each nano-tip of the array of the nano-tips that results in initiating a controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips such as CNTs, communicatively create a conductive path between the cathode plate and the substrate, the radiation detector is capable of determining at least one radiation property.

2. The radiation detector of claim 1, wherein the radiation detector within the radiation particles induces ionization in the at least one gas or gas mixture so as to have a radiation induced controlled discharge of electrons and ions.

3. The radiation detector of claim 2, wherein the electric field is utilized to guide ionization electron (ion) drifting towards the anode (cathode) or portion of the anode (cathode) for one or more readout signal.

4. The radiation detector of claim 1, wherein the electric field near each nano-tip of the array of the nano-tips is utilized to guide electron drifting and to create an arrangement of an electron avalanche that assists in the conductive path between the cathode plate and the substrate, so as to produce the discharge of electrons and ions from at least one gas or at least one gas mixture.

5. The radiation detector of claim 1, wherein the electrical field near the array of nano-tips is sufficient to create one of:

more than a factor of X amplification, where X is within a range of 3 to 100 or more through the discharge of electrons and ions such as an electron avalanche for one or more readout signal;

or orders of magnitude through the discharge of electrons an ions such as an electron avalanche for one or more readout signal.

6. The radiation detector of claim 1, wherein the array of nano-tips is disposed over substantially an entire surface of the substrate.

7. The radiation detector of claim 1, wherein the array of nano-tips is disposed on the portion of the anode plate in a pattern, the pattern is from the group consisting of a serpentine circuit, a geometric design, a non-geometric design, a uniform design, a non-uniform design or some combination thereof.

8. The radiation detector of claim 1, wherein the array of nano-tips is from the group consisting of one of:

carbon nanotubes, single walled CNTs;

multi-walled carbon nano-tubes (MWNTs);

bundled or aligned CNTs;

staged nano-tubes on top of MWNTs;

shaped nano-wires;

nano-structures such as nano-grass;

micro-machined micro-tips from semi-conductor such as silicon, germanium;

chemically etched micro-tips from semi-conductor such as silicon, germanium;

wide-band gap materials such as diamond along with metal coatings applied to the one or more gas chamber to enhance conductivity;

or micro-tips attached with natural formed structures such as diamondoids.

9. The radiation detector of claim 1, wherein the array of nano-tips is from the group consisting of one of:

a field emitter array (FEA), a point-like structure that enhances a local electric field suitable for initiating avalanches that is positively biased or a point-like structure that enhances a local electric field suitable for initiating avalanches that is for field emissions that is negatively biased.

10. The radiation detector of claim 1, wherein the array of nano-tips are geometrically placed within the one or more gas chamber similarly as wires of a traditional wire chamber are geometrical placed.

11. The radiation detector of claim 2, wherein each discharge of electrons and ions produce one or more amplified signal readout that is recorded by at least one processor in communication with the one or more gas chamber and the external power source.

12. The radiation detector of claim 2, wherein for each discharge of electrons and ions produce one or more amplified signal readout, the one or more amplified signal readout provides a position information for one or more particle being detected.

13. The radiation detector of claim 1, further comprising an electric charge measuring device in communication with the cathode and substrate and capable of monitoring an amount of electric charge.

14. The radiation detector of claim 1, wherein the radiation detector has a width from about 100 μ

m to approximately 3 meters or more and a length from about 2 mm to approximately 3 meters or more.

15. The radiation detector of claim 1, wherein the one or more gas chamber and radiation detector have a shape from the group consisting of one of a geometric shape such as a cylindrical shape, a non-geometric shape, a uniform shape, a non-uniform shape, a wave-like shape or a fan-like shape.

16. The radiation detector of claim 1, wherein the one or more gas chamber is one of pressurized, non-pressurized or depressurized.

17. The radiation detector of claim 16, wherein the pressure or depressurization within the one or more gas chamber is controllable.

18. The radiation detector of claim 1, wherein the one or more gas chamber is filled with one of at least one gas or a gas mixture that is one of a controllable pressure, a controllable depressurization or at an ambient pressure.

19. The radiation detector of claim 1, wherein the one or more gas chamber has one or more operational regions.

20. The radiation detector of claim 19, wherein each operational region of the one or more operational region includes one of at least one pressure, at least one gas, a gas mixture or some combination thereof that fills the operational region.

21. The radiation detector of claim 19, wherein the one or more operational region includes two or more operational regions, each operational region has one of a different pressure, a different gas, a different gas mixture or some combination thereof filling the operational region.

22. The radiation detector of claim 1, wherein the cathode plate is a material an electric conducting material.

23. The radiation detector of claim 1, wherein the anode plate is a material from the group consisting of one of conducting materials, non-conductive or both.

24. The radiation detector of claim 1, wherein the gap distance between the cathode plate and the anode plate is from approximately 100 μ

m to approximately 10 cm.

25. The radiation detector of claim 1, wherein the cathode plate and the anode plate are separated by one or more spacer by an approximate length from 100 μ

m to approximately 10 cm.

26. The radiation detector of claim 1, the external power source is controllable, the controlled voltage provides for a uniform electric field or a non-uniform electric field.

27. The radiation detector of claim 1, wherein a gas converter is applied to a portion of the one or more gas chamber for the optimization for neutron detection.

28. The radiation detector of claim 1, wherein a portion of the one or more chamber contains at least one layer having one of gadolinium or gadolinium isotopes such as 157 or 155 (¹⁵⁷Gd, ¹⁵⁵Gd) with an approximate thickness from about 1 μ

m to approximately 50 μ

m for the optimization for neutron detection.

29. The radiation detector of claim 1, wherein at least one coating is applied to a portion of the one or more gas chamber for the optimization for neutron detection.

30. The radiation detector of claim 29, wherein the radiation detector further comprises at least one coating applied to a portion of the cathode plate for the optimization for neutron detection.

31. The radiation detector of claim 29, wherein the radiation detector further comprises at least one coating applied to a portion of the anode plate for the optimization for neutron detection.

32. The radiation detector of claim 29, wherein the radiation detector includes one or more three-dimensional structured surface, the one or more three-dimensional structured surface is from the group consisting of:

a periodic structure, a lattice structure, a structure used in catalysts, a structure used in air-duct filters, a honeycomb structure or other like structures.

33. The radiation detector of claim 29, wherein the one or more gas chamber is coated with a neutron converting material and structured with a surface to volume ratio resulting in a neutron detector having a higher neutron detection efficiency over a comparable surface to volume ratio of a known pressurized wire tube.

34. The radiation detector of claim 29, wherein at least one coating contains one of boron or boron enriched in the boron-10 isotope (¹⁰B), and the at least one coating has a thickness from about 0.5 μ

m to approximately 5 μ

m.

35. The radiation detector of claim 29, wherein the at least one coating contains one of lithium or lithium (⁶Li) isotope, and the at least one coating has a thickness from about 3 μ

m to approximately 50 μ

m.

36. The radiation detector of claim 1, wherein the at least one radiation property includes one of detecting radiation, detecting a location of the radiation or detecting a type of radiation.

37. An oil and gas field application radiation detector, the oil and gas field application radiation detector comprising:

one or more chamber, each chamber includes a cathode plate and a substrate separated by a gap;

an array of nano-tips deposited on a portion of the substrate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a radiation induced controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the substrate, the oil and gas field application radiation detector is capable of determining at least one radiation property.

38. A portable radiation detector, the portable radiation detector comprising:

one or more chamber, each chamber includes a cathode plate and a anode plate separated by a gap;

an array of nano-tips deposited on a portion of the anode plate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the anode plate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a radiation induced controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the anode plate, the portable radiation detector is capable of determining at least one radiation property.

39. A movable radiation detector structured and arranged for operation in one of subterranean environment, above ground environment, wellsite environment or downhole environment for oil and gas field applications, the radiation detector comprising:

a cathode plate and a substrate separated by a gap;

an array of nano-tips deposited on a portion of the substrate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a radiation induced controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the substrate, the radiation detector is capable of determining at least one radiation property while in one of a subterranean environment, above ground environment, wellsite environment or downhole environment.

40. A neutron radiation detector structured and arranged for operation in one of subterranean environments, wellsite environments or downhole environments for oil and gas field applications, the neutron radiation detector comprising:

a cathode plate and a substrate separated by a gap, wherein at least one coating contains at least one boron isotope (preferably highly enriched in ¹⁰B) or at least one coating contains a lithium-6 isotope (preferably highly enriched in ⁶Li) or at least one of the gadolinium isotopes (Gd) is applied to a portion of the cathode plate for the optimization for neutron detection;

an array of nano-tips deposited on a portion of the substrate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the substrate, the radiation detector is capable of determining at least one radiation property while in one of a subterranean environment, wellsite environment or downhole environment.

41. A portable neutron radiation detector, the portable neutron radiation detector comprising:

one or more chamber, each chamber includes a cathode plate and a anode plate separated by a gap, wherein at least one coating or at least one thin sheet is applied to a portion of the cathode plate for the optimization for neutron detection;

an array of nano-tips deposited on a portion of the anode plate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the anode plate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a controlled discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the anode plate, the portable radiation detector is capable of determining at least one radiation property.

42. An oil and gas field application neutron radiation detector, the oil and gas field application neutron radiation detector comprising:

one or more chamber, each chamber includes a cathode plate and a substrate separated by a gap, wherein at least one coating or at least one thin sheet is applied to a portion of the cathode plate for the optimization for neutron detection;

an array of nano-tips deposited on a portion of the substrate forms an anode structure for electron charge collection; and

an external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions, each region includes an electric field near each tip of the array of the nano-tips that results in initiating a discharge of electrons and ions from at least one gas or at least one gas mixture;

wherein the plurality of regions having multiple generated electric fields near tips of the array of nano-tips, communicatively create a conductive path between the cathode plate and the substrate, the oil and gas field application neutron radiation detector is capable of determining at least one radiation property.