The present disclosure relates to a time-gated fast neutron transmission radiography system and method. The system makes use of a pulsed neutron source for producing neutrons in a plurality of directions, with at least a subplurality of the neutrons being directed at an object to be imaged. The system also includes a neutron detector system configured to time-gate the detection of neutrons emitted from the pulsed neutron source to within a time-gated window.

Material analysis device (100) comprising a neutron generator (10) for emitting neutrons towards a material to be analysed in pulsed mode; an alpha particle detector (13) for locating the neutrons emitted in a given solid angle by detecting alpha particles associated with these neutrons; at least one gamma ray detector (14) for measuring energy of gamma photons generated by interaction of the neutrons emitted in the given solid angle with the material to be analysed; at least two Compton cameras (15), each for measuring energy of the gamma photons generated by interaction of the neutrons with the material to be analysed and for calculating an incidence cone of these gamma photos; and an electronic circuit adapted for three-dimensionally mapping the presence of at least one chemical element of interest in the material to be analysed based on data provided by the alpha particle detector (13), the gamma ray detector (14) and the Compton cameras (15).

Material analysis device (100) comprising a neutron generator (10) for emitting neutrons towards a material to be analysed in pulsed mode; an alpha particle detector (13) for locating the neutrons emitted in a given solid angle by detecting alpha particles associated with these neutrons; at least one gamma ray detector (14) for measuring energy of gamma photons generated by interaction of the neutrons emitted in the given solid angle with the material to be analysed; at least two Compton cameras (15), each for measuring energy of the gamma photons generated by interaction of the neutrons with the material to be analysed and for calculating an incidence cone of these gamma photos; and an electronic circuit adapted for three-dimensionally mapping the presence of at least one chemical element of interest in the material to be analysed based on data provided by the alpha particle detector (13), the gamma ray detector (14) and the Compton cameras (15).

The present invention relates a security screening device, comprising: a radiation generator for respectively generating X-rays and neutron beams and irradiating same toward an inspection object; an inspection object transfer unit for changing the position of the inspection object; a radiation detector configured to respectively detect X-rays and neutron beams transmitted through the inspection object; and a gamma ray detector installed adjacent to the inspection object and configured to detect a gamma signal generated from the inspection object, wherein the radiation detector acquires image information of the inspection object by using radiation information detected from the X-rays and neutron beams that have passed through the inspection object, and the gamma ray detector analyzes the detected gamma ray to detect the location of the inspection object from the analysis of the inspection object and the image information.

The present invention relates a security screening device, comprising: a radiation generator for respectively generating X-rays and neutron beams and irradiating same toward an inspection object; an inspection object transfer unit for changing the position of the inspection object; a radiation detector configured to respectively detect X-rays and neutron beams transmitted through the inspection object; and a gamma ray detector installed adjacent to the inspection object and configured to detect a gamma signal generated from the inspection object, wherein the radiation detector acquires image information of the inspection object by using radiation information detected from the X-rays and neutron beams that have passed through the inspection object, and the gamma ray detector analyzes the detected gamma ray to detect the location of the inspection object from the analysis of the inspection object and the image information.

A method and apparatus for neutron radiography is provided for the examination of elongate radioactive items, primarily nuclear fuel elements, and also for the non-destructive testing of irradiated and non-irradiated objects in order to determine the internal structure and material composition thereof. The method and apparatus include placing an object under examination into a protective container. A detection system includes a rotatable limb with a mounting seat for securing neutron detectors in a diametric groove. The limb being mounted to be rotatable by a set angle about an axis parallel to the axis of the object under examination and having a semi-circular recess therein for the passage of an elongate object as the limb rotates by an angle .sub.i relative to the direction of a neutron beam.

A method and apparatus for neutron radiography is provided for the examination of elongate radioactive items, primarily nuclear fuel elements, and also for the non-destructive testing of irradiated and non-irradiated objects in order to determine the internal structure and material composition thereof. The method and apparatus include placing an object under examination into a protective container. A detection system includes a rotatable limb with a mounting seat for securing neutron detectors in a diametric groove. The limb being mounted to be rotatable by a set angle about an axis parallel to the axis of the object under examination and having a semi-circular recess therein for the passage of an elongate object as the limb rotates by an angle .sub.i relative to the direction of a neutron beam.

Various embodiments include apparatus and methods to conduct neutron-neutron measurements and to evaluate quality of cement between a casing and a formation. A tool can include a neutron source, a far detector, and a near detector, where the far detector and the near detector detect neutrons in response to activation of the neutron source. Measured counts of the detected neutrons can be compared with respect to expected counts of neutrons. From one or more comparisons, the quality of the cement can be evaluated. Additional apparatus, systems, and methods are disclosed.

Various embodiments include apparatus and methods to conduct neutron-neutron measurements and to evaluate quality of cement between a casing and a formation. A tool can include a neutron source, a far detector, and a near detector, where the far detector and the near detector detect neutrons in response to activation of the neutron source. Measured counts of the detected neutrons can be compared with respect to expected counts of neutrons. From one or more comparisons, the quality of the cement can be evaluated. Additional apparatus, systems, and methods are disclosed.

A neutron grid, comprises: a grid including: a plurality of spacers through which at least a part of first neutrons from a target passes; and a plurality of absorbers to absorb at least a part of second neutrons scattered thorough the target, the spacers and the absorbers being alternately arranged along a first direction and extending along a second direction intersecting with the first direction; and a pair of covers through which at least a part of the first neutrons and at least a part of the second neutrons pass, sandwiching the grid along a third direction intersecting with the first and second directions. A thermal expansion coefficient difference between one of the spacers and one of the absorbers is 910.sup.6/ C. or less, or Young's modulus of the spacer is 100 GPa or more.