Geological tomography using cosmic rays

• US 20060180753A1
• Filed: 02/17/2006
• Published: 08/17/2006
• Est. Priority Date: 02/17/2005
• Status: Active Grant

• Current Assignee: Advanced Applied Physics Solutions, Inc.
• Original Assignee: Advanced Applied Physics Solutions, Inc.
• Inventors: Bryman, Douglas
• Granted Patent: US 7,488,934 B2
• Time in Patent Office: Days
• US Class Current: 250/266
• CPC Class Codes: G01T 1/203 the detector being made of plastics
• CPC Class Codes: G01V 5/04 specially adapted for well-logging
• CPC Class Codes: G01V 5/08 using primary nuclear radiation sources or X-rays , e.g. for inducing radioactivity; investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays, neutrons G01N23/00

Abstract

Disclosed are a system configured for detecting cosmic ray muon (CRM) flux along a variety of trajectories through a subterranean test region, collecting the muon detection data and processing the data to form a three-dimensional density distribution image corresponding to the test region. The system may be used for identifying concentrations of high (or low) density mineral deposits or other geological structures or formations well below the earth'"'"'s (or ocean floor) surface. The system may be utilized for imaging geological materials and structures of higher and/or lower density in a test region having a depth of several kilometers or more.

Claims

1. A method for mapping subterranean densities in a survey region comprising:

positioning a plurality of muon detectors at a plurality of subterranean locations adjacent the test region;

collecting muon detection data from the detectors for a plurality of intersecting trajectories; and

processing the collected muon detection data to form a density map of the test region.

2. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the detectors may not be manually positioned in subterranean locations.

3. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the subterranean location accommodates objects having only one dimension in excess of 12 cm.

4. The method for mapping subterranean densities in a survey region according to claim 1, further comprising:

repositioning the plurality of muon detectors to a second plurality of subterranean locations adjacent the test region; and

collecting additional muon detection data from the detectors for a second plurality of intersecting trajectories; and

processing the collected muon detection data and additional muon detection data to obtain a three-dimensional density map of the test region.

5. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the plurality of muon detectors are arranged in substantially vertically oriented groupings.

6. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the plurality of muon detectors are arranged in substantially horizontally oriented groupings.

7. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the plurality of muon detectors include a first plurality of muon detectors arranged in substantially horizontally oriented grouping; and

a second plurality of muon detectors arranged in a substantially vertically oriented grouping.

8. The method for mapping subterranean densities in a survey region according to claim 1, further comprising:

collecting detector specific inertial data while positioning the plurality of muon detectors;

processing the inertial data to determine the subterranean locations reached by the muon detectors.

9. The method for mapping subterranean densities in a survey region according to claim 1, further comprising:

collecting detector group inertial data while positioning an associated grouping of muon detectors;

processing the inertial data to determine the subterranean locations reached by the associated grouping of muon detectors.

10. The method for mapping subterranean densities in a survey region according to claim 1, further comprising:

arranging the plurality of muon detectors in a first configuration to detect muon flux along a first plurality of trajectories; and

arranging the plurality of muon detectors in a second configuration to detect muon flux along a second plurality of trajectories.

11. The method for mapping subterranean densities in a survey region according to claim 10, wherein:

the second configuration is achieved by reorienting a sensor module within the muon detector.

12. The method for mapping subterranean densities in a survey region according to claim 10, wherein:

the first configuration and the second configuration are obtained with each muon detector maintained at a single subterranean location.

13. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the collected muon detection data is processed in conjunction with topographic data in order to correct for surface irregularities in the test region.

14. The method for mapping subterranean densities in a survey region according to claim 1, wherein:

the collected muon detection data is processed in conjunction with geological data in order to correct for strata irregularities in the test region.

15. The method for mapping subterranean densities in a survey region according to claim 13, wherein:

the collected muon detection data is further processed in conjunction with geological data in order to correct for strata irregularities in the test region.

16. A system for mapping subterranean densities comprising:

a plurality of muon detectors configured for deployment in subterranean test locations for detecting muon flux data associated with a subterranean test region;

a positioning device for determining the location of the test locations;

a communication device connected to the muon detectors for receiving and transmitting the detected muon flux data;

a processor configured for receiving the detected muon flux data and manipulating the detected muon flux data to produce a density map corresponding to the subterranean test region.

17. The system for mapping subterranean densities according to claim 16, wherein:

the positioning device includes an inertial measurement unit associated with each muon detector.

18. The system for mapping subterranean densities according to claim 16, wherein:

the positioning device includes an inertial measurement unit associated with a group of muon detectors.

19. The system for mapping subterranean densities according to claim 16, wherein:

at least one of the muon detectors incorporates an additional assembly selected from a group consisting of

a memory device configured to receive and store detected muon flux data and

a shielding assembly for suppressing the detection of soft particles.

20. The system for mapping subterranean densities according to claim 16, wherein:

at least one of the muon detectors incorporates an additional assembly selected from a group consisting of

a magnetometer arranged and configured for analyzing a local magnetic field in which the muon detector is positioned and

a device configured to generate a local magnetic field for evaluating a momentum value for muons entering the muon detector.