Various embodiments of the present invention are directed toward systems and methods relating to security screening. For example, a screening system includes a chamber configured to accommodate a user to be screened, and a chamber scanner. The chamber scanner is configured to scan the user to identify whether the user is carrying an undivested item that needs to be divested. The chamber is configured to release the user to proceed from the chamber to a secure area, upon confirmation that no undivested items are to be divested.

The present specification discloses methods for scanning objects for the presence of lithium batteries. Normalized transmission X-ray data is used to generate organic, effective Z, and attenuation-based images. These images are then segmented using a combination of thresholding and region growing techniques to identify regions of interest. The regions are classified as lithium batteries or other objects, based on characteristics such as area of the region, its organic intensity, Z.sub.eff number, shape, spatial arrangement and texture.

A calculation method for a dual-energy X-ray imaging system is provided. The calculation method for the dual-energy X-ray imaging system includes the following steps. A plurality of material attenuation coefficient ratio of the dual-energy projection image are established according to the reference materials with known material characteristics. The effective atomic number of each reference material and the material attenuation coefficient ratio are used to establish a calibration data set. A rational polynomial approximation method is adopted to obtain the characteristic model related to the material attenuation coefficient ratio of the reference material and the effective atomic number of the reference material. The material attenuation coefficient ratio of the dual-energy projection image of unknown material is established. The material attenuation coefficient ratio of the unknown material is substitute into the characteristic model to obtain the effective atomic number corresponding to the unknown material.

The present invention is directed to an inspection system that has a radiation source, a detector array, an inspection region, and a processing unit, where the processing unit a) obtains a radiographic image, b) segments the radiographic image based on radiation attenuation or transmission, c) identifies at least one segmented area on the radiographic image, d) filters the at least one segmented area using at least one geometric filter, e) generates feature vectors using the filtered segmented area; and f) compares the feature vectors against predefined values to determine whether a high-atomic-number object is present.

A drive-through scanning system comprises a radiation generating means arranged to generate radiation at two different energy levels and direct it towards a scanning volume, detection means arranged to detect the radiation after it has passed through the scanning volume, and control means arranged to identify a part of a vehicle within the scanning volume, to allocate the part of the vehicle to one of a plurality of categories, and to control the radiation generating means and to select one or more of the energy levels depending on the category to which the part of the vehicle is allocated.

The disclosure provides a multi-power multi-dosage accelerator. The multi-power multi-dosage accelerator comprises an electron gun configured to provide a first voltage of the electron gun and a second voltage of the electron gun, and an accelerating tube configured to generate a first X-ray having a first dosage and first power according to the first voltage of the electron gun and generate a second X-ray having a second dosage and second power according to the second voltage of the electron gun, wherein the first dosage is a dosage which can be accepted by human bodies and is much less than the second dosage, the first X-ray is used for inspecting a first area where a person is located, and the second X-ray is used for inspecting a second area where goods are located.

The present invention provides a CT image calibration method and device and a CT system. The method includes: arranging a fixed calibration element at the outside of a channel area and within the maximal reconstruction area of a CT scanning device, and storing the theoretical value of the fixed calibration element; collecting the projection data of the fixed calibration element to obtain the actual reconstructed image of the fixed calibration element; and comparing the actual reconstructed image with the stored corresponding theoretical value, to establish a mapping function for correcting the actual reconstructed image into the theoretical value. By adopting the present invention, the calibration quality can be effectively improved, the image calibration effect is enhanced, the reliability of the CT scanning device is improved and the maintenance cost is saved, thus the practical application value is very high.

The invention provides a device (100) for screening one or more items (101,1806) of freight or baggage for one or more types of target material, the device comprising: a source (200, 201,1800) of incident radiation (204,206,1804) configured to irradiate the one or more items (101,1806); a plurality of detectors (202,209,1807, 301) adapted to detect packets of radiation (205,207,1700) emanating from within or passing through the one or more items (101, 1806) as a result of the irradiation by the incident radiation (204, 206, 1804), each detector being configured to produce an electrical pulse (312) caused by the detected packets having a characteristic size or shape dependent on an energy of the packets; one or more digital processors (203, 210, 303, 304, 306, 305) configured to process each electrical pulse to determine the characteristic size or shape and to thereby generate a detector energy spectrum for each detector of the energies of the packets detected, and characterise a material associated with the one or more items based on the energy spectrum.

The present application discloses a CT system and a detection apparatus for the CT system. The detection apparatus includes: a high-energy detector assembly including a plurality of rows of high-energy detectors arranged along a predetermined trajectory; a low-energy detector assembly including a plurality of rows of low-energy detectors arranged at intervals along the predetermined trajectory, the low-energy detector assembly and the high-energy detector assembly being disposed in a stack; a number of rows of the low-energy detectors is smaller than a number or rows of the high-energy detectors; and each row of the low-energy detectors covers a row of high-energy detectors.

An array (1) for detecting electromagnetic radiation is provided for a radiographic inspection system (20). The array has a plurality of detector elements (2) arranged consecutively along a scan line which extends in a first direction (Y). Each of the detector elements has a detection surface (3) for receiving electromagnetic radiation and converting the received electromagnetic radiation into a corresponding detection signal. Each detection surface (3) has a surface normal (4, N) that extends in a common plane (S) and converges into a common focus (5). The common plane (S) extends in the first direction (Y). The distances between the common focus and the detection surfaces along the respective surface normal (4, N) are different for at least two detector elements.