A scanning method which is a method of identifying a change in the density of an object includes arranging a source of ionizing radiation and an array of radiation detectors Dn, where n is an integer from 1 to N, capable of detecting the radiation in such a way that radiation counts are counted by the detectors as the source and detectors are rotated around the object and normalized counts values are collated in a matrix such that a pattern may be detected within the matrix from which the presence of a change in the density of the object at a location lying on at least one of the radiation paths may be inferred.

A -ray scanner includes a Solid-State Single-Photon Detector (SSSPD) and a -ray source, which may be a radioisotope such as Americium oxide (Am-241) that may not require certification since it has a low intensity that is safe even over extended periods of exposure to a human body. The -ray scanner may be used for monitoring a fixed object such as a pipe and includes an imaging assembly having a stationary annular gantry surrounding the pipe and an armature that fixedly supports the -source and the detector in mutual opposed alignment, so that they are constrained to move together. The armature rides around an inside periphery of the gantry, while the armature or the gantry moves laterally in a direction parallel to a rotation axis of the armature so as to move the -ray beam around and along the pipe.

The present application relates to a dual-energy detection method, system and apparatus. The apparatus includes: a first pixel detector array proximal to a ray source, configured to detect ray source photons having relatively low energy; and a second pixel detector array distal from the ray source, configured to detect ray source photons having relatively high energy; wherein the first pixel detector array includes a plurality of rows of first pixel detectors, the first pixel detector including a first sensitive medium, a first photosensitive device, a first incidence plane, and a first window; the second pixel detector array includes a single row of second pixel detectors, the second pixel detector including a second sensitive medium, a second photosensitive device, a second incidence plane, and a second window; and each of the second pixel detectors has the same pixel area as corresponding plurality of first pixel detectors thereof.

Some embodiments include a radiographic inspection system, comprising: a clamp comprises a housing, a base, three clamping contacts, and an actuator; wherein: the clamp is configured to be positioned around a structure and to be coupled to the structure; the base is coupled to the housing through a rotary bearing, is moveable relative to the housing, and is configured to support a detector such that the detector may rotate around the structure while the clamp remains stationary relative to the structure; and the three clamping contacts are moveable relative to the housing via the actuator in a manner such that the three clamping contacts self-center on the structure.

A high-quality tomographic image acquisition device for a densely arranged spent nuclear fuel according to an embodiment of the present inventive concept relates to an gamma emission tomography device for detecting radiation of a fuel assembly which receives a plurality of fuel rods and may comprise: a first detection part disposed on one side of the fuel assembly and detecting radiation emitted from the fuel assembly; and a second detection part including a rod-shaped sealing part disposed inside the fuel assembly and a detection member disposed inside the sealing part and detecting radiation emitted from the fuel assembly.

Some embodiments include a radiographic inspection system, comprising: a clamp comprises a housing, a base, three clamping contacts, and an actuator; wherein: the clamp is configured to be positioned around a structure and to be coupled to the structure; the base is coupled to the housing through a rotary bearing, is moveable relative to the housing, and is configured to support a detector such that the detector may rotate around the structure while the clamp remains stationary relative to the structure; and the three clamping contacts are moveable relative to the housing via the actuator in a manner such that the three clamping contacts self-center on the structure.