A muon detector system capable of determining muon direction and flight trajectory or path is disclosed. The muon detector system includes scintillators for determining muon direction, and an array of muon detectors arranged in orthogonal layers for determining flight trajectory. The system can be used for tomographic and telescopic mode imaging, and may be used for imaging concealed and/or subterranean objects.

The present specification provides a detector for an X-ray imaging system. The detector includes at least one high resolution layer having high resolution wavelength-shifting optical fibers, each fiber occupying a distinct region of the detector, at least one low resolution layer with low resolution regions, and a single segmented multi-channel photo-multiplier tube for coupling signals obtained from the high resolution fibers and the low resolution regions.

A radiation monitor apparatus and method based on wavelength-dependent optical absorption in fused silica optical fibers. The radiation monitor uses the radiation induced optical changes in fused silica optical fibers as a way to quantify and differentiate the large doses of radiation from high energy photons and neutrons as well as providing a method to extend the sensitivity over a large dynamic range of doses from 103 to beyond 106 rads. The radiation monitor enables dynamic monitoring of highly ionizing radiation environments. The radiation monitor reduces sensitivity saturation at high dose levels, provides increased sensitivity over a large dynamic range of doses, and enables differentiation between high energy photon and neutron contributions or poor signal to noise.

A radiation monitor apparatus and method based on wavelength-dependent optical absorption in fused silica optical fibers. The radiation monitor uses the radiation induced optical changes in fused silica optical fibers as a way to quantify and differentiate the large doses of radiation from high energy photons and neutrons as well as providing a method to extend the sensitivity over a large dynamic range of doses from 103 to beyond 106 rads. The radiation monitor enables dynamic monitoring of highly ionizing radiation environments. The radiation monitor reduces sensitivity saturation at high dose levels, provides increased sensitivity over a large dynamic range of doses, and enables differentiation between high energy photon and neutron contributions or poor signal to noise.

Methods for discriminating among x-ray beams of distinct energy content. A first volume of scintillation medium converts energy of incident penetrating radiation into scintillation light which is extracted from a scintillation light extraction region by a plurality of optical waveguides that convert the scintillation light to light of a longer wavelength. An x-ray beam initially incident upon the first volume of scintillation medium and traversing the first volume is then incident on a second volume of scintillation medium. The first and second scintillation media may be separated by an absorber or one or more further volumes of scintillation medium, and may also have differential spectral sensitivities. Scintillation light from the first and second scintillation volumes is detected in respective detectors and processed to yield a measure of respective low energy and high-energy components of the incident x-ray beam.

Methods for discriminating among x-ray beams of distinct energy content. A first volume of scintillation medium converts energy of incident penetrating radiation into scintillation light which is extracted from a scintillation light extraction region by a plurality of optical waveguides that convert the scintillation light to light of a longer wavelength. An x-ray beam initially incident upon the first volume of scintillation medium and traversing the first volume is then incident on a second volume of scintillation medium. The first and second scintillation media may be separated by an absorber or one or more further volumes of scintillation medium, and may also have differential spectral sensitivities. Scintillation light from the first and second scintillation volumes is detected in respective detectors and processed to yield a measure of respective low energy and high-energy components of the incident x-ray beam.

The present invention relates to devices and methods for measuring neutron fluence at a pre-selected location which is positioned in a nuclear power plant. The devices and methods include passing neutrons through a fiber optic cable. The fiber optic cable has disposed therein a neutron sensitive material which is capable of absorbing the neutrons to produce a gas. The gas results in a build-up of pressure in the fiber optic cable which causes a change in the optical stress birefringence pattern. This change is measured and used to determine the amount of gas in the fiber optic cable, the number of neutrons absorbed by the neutron sensitive material and subsequently, the neutron fluence at the pre-selected location.

In particular, the devices and methods of the invention are effective without the need to employ a radioactive material.

The present invention relates to devices and methods for measuring neutron fluence at a pre-selected location which is positioned in a nuclear power plant. The devices and methods include passing neutrons through a fiber optic cable. The fiber optic cable has disposed therein a neutron sensitive material which is capable of absorbing the neutrons to produce a gas. The gas results in a build-up of pressure in the fiber optic cable which causes a change in the optical stress birefringence pattern. This change is measured and used to determine the amount of gas in the fiber optic cable, the number of neutrons absorbed by the neutron sensitive material and subsequently, the neutron fluence at the pre-selected location.

In particular, the devices and methods of the invention are effective without the need to employ a radioactive material.

An article can include a body including a fluorescent material and a wavelength shifting fiber. In an embodiment, the fiber can have a cross-sectional dimension of at least 1.5 mm, and outer dimensions of the body define a volume of at least 5 liters. In another embodiment, the article can include wavelength shifting fibers organized in at least two rows and at least columns. In another aspect, a radiation detector can include a body including a fluorescent material; a wavelength shifting fiber having a cross-sectional area; and a photosensor including a light-receiving surface having a light-receiving area of at least 9 mm.sup.2, wherein the cross-sectional area of the wavelength shifting fiber is at least 25% of the light-receiving area. The article and radiation detector are well suited for relatively large radiation detectors that have bodies with relatively short attenuation lengths.

A radiation monitor apparatus and method based on wavelength-dependent optical absorption in fused silica optical fibers. The radiation monitor uses the radiation induced optical changes in fused silica optical fibers as a way to quantify and differentiate the large doses of radiation from high energy photons and neutrons as well as providing a method to extend the sensitivity over a large dynamic range of doses from 103 to beyond 106 rads. The radiation monitor enables dynamic monitoring of highly ionizing radiation environments. The radiation monitor reduces sensitivity saturation at high dose levels, provides increased sensitivity over a large dynamic range of doses, and enables differentiation between high energy photon and neutron contributions or poor signal to noise.