Abstract: Disclosed are a system and method 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. In at least one embodiment, the system may be used for identifying concentrations of higher (or lower) 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.

Abstract: The present invention provides an improved gamma ray detector module and a method of operating such a detector module for more accurately determining the position of a gamma ray interaction within the detector. The detector module includes an induction array arranged at an offset angle relative other arrays utilized in the detector, whereby the relative timing of the detection of ionization electrons by the induction array and a collector or anode indicate at least one coordinate corresponding to the location of the interaction that produced the ionization electron. This secondary locating apparatus and method supplements or replaces conventional locating apparatus and methods for improving the accuracy or reducing the complexity of the detection apparatus.

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.

Abstract: Disclosed are a system and method 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. In at least one embodiment, the system may be used for identifying concentrations of higher (or lower) 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.

Abstract: Provided are new methods for enhancing the selection of true (T) annihilation events relative to the inclusion of true scattered (TS) and random (R) annihilation events in PET tomographs and thereby improving the sensitivity and/or resolution of PET scanners. The methods include reconstruction of Compton scattering interactions in the ?-ray detectors for determining the angles of incidence of the ?-rays received at the detectors and may utilize ?-ray polarization effects and electron recoil data associated with positron annihilation and Compton scattering. The use of the ?-ray polarization effects provides an improved ability for selecting data corresponding to T events while simultaneously suppressing data corresponding to TS and R events during PET applications.

Abstract: An improved gamma ray detector and method for discriminating between “true” pairs of gamma rays produced by a single positron annihilation event and those randomly occurring “pairs” of gamma rays that may fall within the conventional acceptance criteria for “true” pairs. The gamma ray detector incorporates an additional array of “veto” detectors arranged adjacent or around a primary detector array. The array of “veto” detectors is configured to detect gamma rays that escape detection in the primary detector array. The detection data from both the primary detector array and the veto detector array are used as inputs into a discrimination circuit for “vetoing” those pairs of gamma rays detected by the primary detector array that are likely to be the result of two or more unrelated positron annihilation events.

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.

Abstract: Provided are new methods for enhancing the selection of true (T) annihilation events relative to the inclusion of true scattered (TS) and random (R) annihilation events in PET tomographs and thereby improving the sensitivity and/or resolution of PET scanners. The methods include reconstruction of Compton scattering interactions in the ?-ray detectors for determining the angles of incidence of the ?-rays received at the detectors and may utilize ?-ray polarization effects and electron recoil data associated with positron annihilation and Compton scattering. The use of the ?-ray polarization effects provides an improved ability for selecting data corresponding to T events while simultaneously suppressing data corresponding to TS and R events during PET applications.

Abstract: The present invention provides an improved gamma ray detector module and a method of operating such a detector module for more accurately determining the position of a gamma ray interaction within the detector. The detector module includes an induction array arranged at an offset angle relative other arrays utilized in the detector, whereby the relative timing of the detection of ionization electrons by the induction array and a collector or anode indicate at least one coordinate corresponding to the location of the interaction that produced the ionization electron. This secondary locating apparatus and method supplements or replaces conventional locating apparatus and methods for improving the accuracy or reducing the complexity of the detection apparatus.

Abstract: An improved gamma ray detector and method for discriminating between “true” pairs of gamma rays produced by a single positron annihilation event and those randomly occurring “pairs” of gamma rays that may fall within the conventional acceptance criteria for “true” pairs. The gamma ray detector incorporates an additional array of “veto” detectors arranged adjacent or around a primary detector array. The array of “veto” detectors is configured to detect gamma rays that escape detection in the primary detector array. The detection data from both the primary detector array and the veto detector array are used as inputs into a discrimination circuit for “vetoing” those pairs of gamma rays detected by the primary detector array that are likely to be the result of two or more unrelated positron annihilation events.

Abstract: A method and apparatus for determining the position of a gamma ray interaction are disclosed. A medium that emits light in response to an interaction between a gamma ray and the medium is provided. A plurality of photodetectors is used to detect the light and determine a first three-dimensional position of the interaction. A field is produced in the medium that directs ionization electrons resulting from the interaction to a collector. A portion of a shutter system that corresponds to the interaction is opened. The shutter selectively blocks and permits the passage of the ionization electrons to the collector. A second three-dimensional position of the interaction is determined by localizing a two-dimensional position of the interaction in the collector and determining a third dimension based on a time of arrival of the ionization electrons relative to when the light is detected.

Abstract: A method and apparatus for determining the position of a gamma ray interaction are disclosed. A medium that emits light in response to an interaction between a gamma ray and the medium is provided. A plurality of photodetectors is used to detect the light and determine a first three-dimensional position of the interaction. A field is produced in the medium that directs ionization electrons resulting from the interaction to a collector. A portion of a shutter system that corresponds to the interaction is opened. The shutter selectively blocks and permits the passage of the ionization electrons to the collector. A second three-dimensional position of the interaction is determined by localizing a two-dimensional position of the interaction in the collector and determining a third dimension based on a time of arrival of the ionization electrons relative to when the light is detected.

Abstract: A method and apparatus for determining the position of a gamma ray interaction are disclosed. A medium that emits light in response to an interaction between a gamma ray and the medium is provided. A plurality of photodetectors is used to detect the light and determine a first three-dimensional position of the interaction. A field is produced in the medium that dire ionization electrons resulting from the interaction to a collector. A portion of a shutter system that corresponds to the interaction is opened. The shutter selectively blocks and permits the passage of the ionization electrons to the collector. A second three-dimensional position of the interaction is determined by localizing a two-dimensional position of the interaction in the collector and determining a third dimension based on a time of arrival of the ionization electrons relative to when the light is detected.

Abstract: A method and apparatus for determining the position of a gamma ray interaction are disclosed. A medium that emits light in response to an interaction between a gamma ray and the medium is provided. A plurality of photodetectors is used to detect the light and determine a first three-dimensional position of the interaction. A field is produced in the medium that directs ionization electrons resulting from the interaction to a collector. A portion of a shutter system that corresponds to the interaction is opened. The shutter selectively blocks and permits the passage of the ionization electrons to the collector. A second three-dimensional position of the interaction is determined by localing a two-dimensional position of the interaction in the collector and determining a third dimension based on a time of arrival of the ionization electrons relative to when the light is detected.

Abstract: A gamma ray detector for determining the position of gamma ray interactions has at least one module. Each module has a converter for converting gamma rays to charged particles, a scintillator for emitting light in response to charged particles produced by the converter, a photodetector to determine when light has been emitted from the scintillator, a two-coordinate position detector for determining the X and Y coordinates of charged particles interacting with the position detector, and a signal device for signaling the presence of emitted light in the photodetector and for activating the position detector.