Systems and methods for analyzing underwater, subsurface and atmospheric environments

• US 8,299,424 B2
• Filed: 04/30/2007
• Issued: 10/30/2012
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Woods Hole Oceanographic Institution
• Original Assignee: Woods Hole Oceanographic Institution
• Inventors: Camilli, Richard
• Primary Examiner(s): Logie, Michael
• Application Number:
  US11/796,874
• Publication Number:
  US 20090084976A1
• Time in Patent Office: 2,010 Days
• Field of Search: 250/288, 250/298, 250/281, 250/282, 73/645.6, 73/530.1
• US Class Current: 250/288
• CPC Class Codes: H01J 49/24 Vacuum systems, e.g. maintaining desired pressures

Abstract

The systems and methods described herein include, among other things, systems capable of being deployed for long periods of time in oceanic, subsurface and atmospheric environments. The systems typically include mass spectrometers to measure low molecular weight gases dissolved in the water and volatile chemicals in air and water, and can move through the ocean, subsurface and atmospheric environment to take samples over a large geographic area. Additionally, these mass spectrometer devices are small and require little power and thereby facilitate the development of sample collection devices that can be placed at a remote location and operated for a substantial period of time from an on-board power supply such as a battery or a fuel cell. Such small and lightweight mass spectrometer devices when combined with low power AUVs (Autonomous Underwater Vehicles) and other manned and un-manned vehicles, can take samples over substantial distances and for a substantial period of time.

Claims

1. A system for performing a chemical analysis of substances in an underwater environment at a particular depth, comprising

a housing,

an inlet assembly, connected to the housing and capable of allowing one or more substances from the underwater environment to diffuse into the housing, wherein the inlet assembly includes an inlet body, a recess, an inlet membrane disposed proximate to the recess, and a backing plate positioned within the recess such that a gap is created between the inlet body and the backing plate for the substances to pass through the inlet membrane and the recess,

a vacuum chamber disposed within the housing, capable of maintaining a vacuum and connected to the inlet assembly for receiving the one or more substances,

an NEG-ion pump disposed within the housing and connected to the vacuum chamber for generating a vacuum therein,

an analyzer disposed within the vacuum chamber for detecting one or more of the substances, and

a magnet disposed near the vacuum chamber for generating a magnetic field within a portion of the analyzer.

2. The system of claim 1, wherein the housing is substantially formed from water impermeable materials.

3. The system of claim 1, wherein the housing is capable of withstanding a pressure greater than about 500 atmospheres.

4. The system of claim 1, wherein the particular depth is greater than about 2500 meters.

5. The system of claim 1, wherein the housing is formed from materials capable of being disposed in water for a length of time greater than about one month.

6. The system of claim 1, wherein the housing is substantially cylindrically shaped.

7. The system of claim 1, wherein the inlet membrane is formed from hydrophobic materials.

8. The system of claim 1, wherein the inlet membrane comprises a polymer.

9. The system of claim 8, wherein the polymer includes at least one of high-density polyethylene (HDPE), polymethylpentene (PMP), polypropylene, trespaphan GND, polytetrafluoroethylene, Hostaflon PFA, and polyimino-1-oxohexamethylene.

10. The system of claim 1, wherein the inlet assembly includes an inlet tube connecting the inlet membrane and the vacuum chamber.

11. The system of claim 1, wherein the backing plate is attached to the inlet membrane for providing additional structural support to the inlet membrane.

12. The system of claim 1, wherein a portion of the inlet assembly is disposed within the housing and a portion of the inlet assembly is disposed outside the housing.

13. The system of claim 1, wherein the inlet assembly extends outwardly from the housing.

14. The system of claim 1, wherein the vacuum chamber includes closable openings for connecting at least one of the inlet tube, the ion pump and control electronics.

15. The system of claim 1, wherein one or more of the magnetic members are disposed in between one or more pole pieces and the magnet carrier.

16. The system of claim 1, wherein the magnet includes a permanent magnet assembly having a magnet carrier, two magnetic members and two pole pieces tapered along one or more edges.

17. The system of claim 1, wherein the magnet includes a permanent magnet assembly having a magnet carrier, one or more magnetic members and one or more pole pieces tapered along one or more edges, the permanent magnet assembly has an asymmetric shape.

18. The system of claim 1, wherein the magnet includes one or more magnetic members formed from NdFeB.

19. The system of claim 1, wherein the magnet includes one or more pole pieces and magnet carrier formed from low carbon steel.

20. The system of claim 1, wherein the magnet is configured to generate a substantially homogenous magnetic field and includes a magnet carrier shaped to minimize fringing effects in the substantially homogeneous magnetic field.

21. The system of claim 1, wherein the magnet is sized and shaped to fit around a portion of the vacuum chamber.

22. The system of claim 1, wherein the analyzer includes

an ion source for ionizing the one or more substances,

a mass selector for separating the ionized substances, and

a detector for detecting the ionized substances.

23. The system of claim 22, wherein the mass selector includes a cycloidal mass selector.

24. The system of claim 22, wherein the detector includes a Faraday cup detector.

25. The system of claim 22, wherein the ion source includes a heated tungsten filament.

26. The system of claim 1, comprising a flow pump connected to the inlet assembly for providing a continuous flow of at least one of water and one or more substances to a region near the inlet assembly.

27. The system of claim 1, comprising a flow pump connected to the inlet assembly for providing a continuous flow of at least one of water and one or more substances to a region near the inlet membrane.

28. The system of claim 26, wherein the flow pump includes an impeller pump.

29. The system of claim 1, comprising at least one of a conductivity sensor, a temperature sensor and a depth sensor.

30. The system of claim 1, comprising a computer connected to the analyzer for at least one of analyzing and storing the one or more detected substances.

31. The system of claim 30, comprising a controller connected to the computer and the analyzer for modifying the operation of at least one of the computer and analyzer in response to one or more of detected substances.

32. The system of claim 1, comprising one or more valves connected to at least one of the inlet assembly and the vacuum chamber.

33. The system of claim 32, comprising a roughing pump connected to at least one of the inlet assembly and the vacuum chamber.

34. The system of claim 1, comprising a navigational controller, for controlling one or more navigational components that assist in navigating through the underwater environment, based at least in part on the one or more substances detected by the analyzer.

35. The system of claim 34, wherein the navigational controller, based on the concentration of the one or more detected substances, provides one or more directional commands to the one or more navigational components to move towards a region, in the underwater environment, having a higher concentration of the one or more detected substances.

36. The system of claim 35, wherein the navigational controller is configured to control the operation of the analyzer within the region.

37. The system of claim 34, wherein the navigational controller includes a computer configured to analyze the one or more detected substances in real-time.

38. The system of claim 1, comprising a turbo-molecular pump disposed within the housing and connected with the NEG-ion pump for generating the vacuum in the vacuum chamber.

39. A system for performing a chemical analysis of substances in an underwater environment at a particular depth, comprising

a water impermeable housing;

an inlet assembly, connected to the housing and capable of allowing one or more substances from the underwater environment to diffuse into the housing, comprising

an inlet body having a recess,

an inlet membrane disposed proximate to the recess, and

a backing plate for supporting the inlet membrane and positioned within the recess such that a gap is created between the inlet body and the backing plate, wherein the gap provides a path for the substances to pass through inlet membrane and the recess;

a vacuum chamber disposed within the housing, capable of maintaining a vacuum and connected to the inlet assembly for receiving the one or more substances;

an analyzer disposed within the vacuum chamber for detecting one or more of the substances; and

a magnet disposed near the vacuum chamber for generating a magnetic field within a portion of the analyzer.

40. The system of claim 39, wherein the gap between the inlet body and the backing plate reduces stress on the inlet membrane.

41. The system of claim 39, wherein the gap between the inlet body and the backing plate provides a short and continuous diffusion path, thereby allowing fast diffusion of the substances through the inlet membrane and the recess.

42. The system of claim 39, wherein the backing plate includes one or more surface slots that extend along a surface of the backing plate facing an opening of the inlet body.

43. The system of claim 42, wherein the one or more surface slots extend along the surface of the backing plate from one or more edges of the backing plate towards the center of the backing plate.

44. The system of claim 42, wherein the backing plate includes one or more side slots along a side surface of the backing plate.

45. The system of claim 44, wherein the one or more side slots are aligned with the one or more surface slots.

46. The system of claim 39, wherein the backing plate is cylindrically shaped.

47. A method for performing a chemical analysis of substances in an underwater environment at a particular depth, comprising

providing a water impermeable housing connected to an inlet assembly and a vacuum chamber, wherein the inlet assembly includes an inlet body having a recess, an inlet membrane disposed proximate to the recess, and a backing plate for supporting the inlet membrane and positioned within the recess such that a gap is created between the inlet body and the backing plate;

allowing a substance from the underwater environment to diffuse into the water impermeable housing;

receiving the substance at the inlet assembly;

allowing the substance to pass through the inlet assembly via the gap between the inlet body and the backing plate;

generating and maintaining a vacuum at the vacuum chamber;

receiving the substance at the vacuum chamber from the inlet assembly; and

detecting the substance via an analyzer disposed within the vacuum chamber.