Abstract: A technique for generating three-dimensional information using radio frequency modulated X-rays includes both a method and an apparatus. In a first aspect, the method includes modulating an X-ray signal with first and second radio frequencies; transmitting the modulated X-ray signal; receiving backscatter; and processing the received backscatter to range a target in the field of view. In another aspect, an apparatus includes a transmitter and a receiver. The transmitter is capable of: modulating an X-ray signal with first and second radio frequencies and transmitting the modulated X-ray signal into a field of view. The receiver is capable of receiving backscatter from the transmitted X-ray signal. Other aspects include variations on these. For example, some aspects are computer implemented, such as a software implemented method, a program storage medium encoded with instruction to perform such a method, and a computing apparatus performed to program such a method.

Abstract: A detector system for capturing and resolving WAXS and SAXS beams is provided along with a device for determining structural information of a material incorporating said detector system and a method for examining the structure of a material using said detector system. The detector system generally comprises a sample capable of interacting with the incident x-ray beam, a primary detector and a secondary detector. Upon interaction with a sample of the material, the incident x-ray beam is scattered into wide angle x-ray scattering (WAXS) beams and small angle x-ray scattering (SAXS) beams that are captured by the primary or secondary detectors.

Abstract: Embodiments of backscatter inspection systems include features to enable inspection of irregular surfaces, tight spacer, and other hard-to-reach places. Some embodiments include arms that maneuver a scan head with at least three degrees of freedom, and some embodiments include arms that maneuver a scan head with at least seven degrees of freedom. Some embodiments include proximity detectors on a scan head or base, detect contact with an object being inspected, and to slow or stop the motion of the system accordingly. Some compact embodiments scan the interior of an object from within, and include a rotating, low-energy source of penetrating radiation, and at least one backscatter detector, which may be stationary, or may rotate with the source.

Abstract: The present disclosure presents, in various aspects and embodiments, a 3D X-ray microscopy imaging technique. Some aspects are directed to various embodiments of an apparatus for use in such a technique, such as an X-ray microscopy imaging system. Other aspects are directed to various embodiments of a method for use in such a technique, like a method for generating an X-ray image that has a grayscale response proportional to range. Some, though not all, aspects of the technique are computer-implemented, and so include encoded program storage media, programmed computing apparatuses, and computer-implemented methods.

Abstract: The present disclosure presents, in various aspects and embodiments, a 3D X-ray reflection microscopy imaging technique. Some aspects are directed to various embodiments of an apparatus for use in such a technique, such as an X-ray reflection microscopy imaging system. Other aspects are directed to various embodiments of a method for use in such a technique, like a method for generating an X-ray image that has a grayscale response proportional to range. Some, though not all, aspects of the technique are computer-implemented, and so include encoded program storage media, programmed computing apparatuses, and computer-implemented methods.

Abstract: A first image including a projection of a portion is generated based on data representing attenuation of higher-energy radiation having a peak energy of at least 1 MeV that passes through a portion of an inspection volume. A second image including a projection of the portion is generated based on data representing attenuation of lower-energy radiation passing through the portion of the inspection volume. A dual-pixel image is created from the first image and the second image. A region of interest is selected from the dual-pixel image. A first basis function that is derived from an attenuation characteristic associated with the region of interest is selected. The region of interest is represented in terms of an amplitude associated with the first basis function and an amplitude associated with the second basis function.

Abstract: A method and system for facilitating the identification and/or authentication of objects, and to a method and system for the marking of objects with an identity and/or as of authentic origin, and a set of objects marked to facilitate subsequent identification and/or authentication are described. The marking comprises incorporating into an object or part thereof or onto a tag mechanically engaged therewith a marker material exhibiting a characteristic radiation interaction response to incident high-energy ionizing radiation from a test source that is known to vary spectroscopically across the spectrum of the source. The presence or otherwise of the marker material may be determined by subsequent interrogation of an object with a suitable radiation source and detector to infer whether an object is of marked identity or origin.

Abstract: Methods and systems for monitoring semiconductor fabrication processes are provided. A system may include a stage configured to support a specimen and coupled to a measurement device. The measurement device may include an illumination system and a detection system. The illumination system and the detection system may be configured such that the system may be configured to determine multiple properties of the specimen. For example, the system may be configured to determine multiple properties of a specimen including: but not limited to, critical dimension and overlay misregistration; defects and thin film characteristics; critical dimension and defects; critical dimension and thin film characteristics; critical dimension, thin film characteristics and defects; macro defects and micro defects; flatness, thin film characteristics and defects; overlay misregistration and flatness; an implant characteristic and defects; and adhesion and thickness.

Abstract: A method for processing a sample in a charged-particle beam microscope. A sample is collected from a substrate and the sample is attached to the tip of a nanomanipulator. The sample is optionally oriented to optimize further processing. The nanomanipulator tip is brought into contact with a stabilizing support to minimize drift or vibration of the sample. The attached sample is then stabilized and available for preparation and analysis.

Abstract: Doped adhesive tape is used during the manufacture of aircraft, including positioning marks, covering orifices from debris, allowing locations to be marked. Any doped adhesive tape inadvertently left in sub-assemblies during the manufacturing process can be detected using backscatter X-ray inspection technology. Detection is facilitated in one embodiment by making the tape thicker, to produce an increased mass density, and in another embodiment by adding a dopant comprising an element that is readily detected by the backscatter X-ray technology. The element can be iodine, and can be incorporated into the backing layer or the adhesive layer of the tape during manufacturing. The use of both thicker tape and a dopant can be used in combination to facilitate detection. If the doped adhesive tape is detected after components are assembled using a backscatter X-ray inspection device, then the doped adhesive tape is removed.

Abstract: A reel-like format for transporting devices under test (DUT) into low power x-ray inspection system allows for high speed transportation and inspection that is several orders of magnitude faster than conventional systems. The system can be configured with a conveyor belt for handling of non-reel suitable DUTs. A stabilizing control mechanism precisely and accurately brings the tape (with components) into the x-raying window, that allows spatial displacement of a portion of the to-be-viewed tape.

Abstract: An improved microcalorimeter-type energy dispersive x-ray spectrometer provides sufficient energy resolution and throughput for practical high spatial resolution x-ray mapping of a sample at low electron beam energies. When used with a dual beam system that provides the capability to etch a layer from the sample, the system can be used for three-dimensional x-ray mapping. A preferred system uses an x-ray optic having a wide-angle opening to increase the fraction of x-rays leaving the sample that impinge on the detector and multiple detectors to avoid pulse pile up.

Abstract: An apparatus to examine a target in a patient includes an x-ray source configured to deliver a first x-ray beam towards the target, a device having an array of openings, the device located at an angle less than 180 degrees relative to a beam path of the first x-ray beam to receive a second x-ray beam resulted from an interaction between the first x-ray beam and the target, and a detector aligned with the device, the detector located at an angle less than 180 degrees relative to the beam path of the first x-ray beam to receive a part of the second x-ray beam from the device that exits through the openings at the device.

Abstract: A Compton radiation detection device for determining of Compton radiation of iron, includes a sensor and a filter arrangement. The filter arrangement is adapted such that the radiation emitted by a test object due to Compton scattering passes a nickel layer and an iron layer before being detected by the sensor. A dispersive ionization chamber includes an ionization chamber having a plurality off ionization volumes and a window. Each ionization volume includes an electrode. Radiation can enter through the window. The ionization volumes are arranged in a beam propagation direction behind each other. Radiation having lower energy is statistically absorbed in ionization volumes located more proximal to the window. Radiation having higher energy is statistically absorbed in the ionization volumes located more distal from the window.

Abstract: The different advantageous embodiments provide a method and apparatus for generating an x-ray beam. The x-ray beam is generated using an x-ray tube. The x-ray tube and a power supply are located inside of a housing connected to a moveable platform. A rotatable wheel connected to the moveable platform is rotated while the x-ray beam is being generated. The rotatable wheel has a number of apertures that allows at least a portion of the x-ray beam to pass through the rotatable wheel as the rotatable wheel rotates.

Abstract: A system displays potential radiation zones in an angiography X-ray laboratory during an angiography procedure, for example, and identifies areas of potentially harmful radiation due to X-ray scatter in an imaging room. An input processor receives data identifying an emitted X-ray dose level applied to an area of a patient anatomy. An image data processor determines level of X-ray radiation dose scatter in different regions of an imaging room indicating regions of potentially harmful radiation, by calculating X-ray scatter dose at different distances from an irradiated patient area as being substantially in proportion to the size of the irradiated area and substantially inversely proportional to the square of the distance from the irradiated area. A visual alert system visually identifies areas of a room of potentially harmful radiation in response to the determination.

Abstract: Several related inventions for estimating scattered radiation in radiographic projections are disclosed. Several of the inventions use scatter kernels of various forms, including symmetric and asymmetric forms. The inventions may be used alone or in various combinations with one another. The resulting estimates of scattered radiation may be used to correct the projections, which can improve the results of tomographic reconstructions. Still other inventions of the present application generate estimates of scattered radiation from shaded or partially shaded regions of a radiographic projection, which may be used to correct the projections or used to adjust the estimates of scattered radiation generated according to inventions of the present application that employ kernels.

Abstract: A method for determining the density of a fluid that includes disposing a gamma-ray source proximate to a vessel containing the fluid is provided. The optimal position of a gamma-ray detector with respect to the gamma-ray source is determined. A gamma-ray detector is position at the optimal position, and the density of the fluid is measured.

Abstract: Apparatus for inspection of a sample includes an X-ray source, which is configured to irradiate a location on the sample with a beam of X-rays. An X-ray detector is configured to receive the X-rays that are scattered from the sample and to output a first signal indicative of the received X-rays. A VUV source is configured to irradiate the location on the sample with a beam of VUV radiation. A VUV detector is configured to receive the VUV radiation that is reflected from the sample and to output a second signal indicative of the received VUV radiation. A processor is configured to process the first and second signals in order to measure a property of the sample.

Abstract: A variable-geometry backscatter inspection system has a radiation detector array including one or more backscatter radiation detectors. The position of a second backscatter radiation detector is variable with respect to the position of a first backscatter radiation detector, so that the size of the detector array may be varied by moving the second radiation detector into or out of a predefined alignment with the first radiation detector. The system may include a movable base, and at least one of the detectors is movable with respect to the base. Methods of inspecting an object include forming a detector array by moving a second radiation detector into a predefined alignment with a first radiation detector, illuminating the object with a pencil beam of penetrating radiation, and detecting backscattered radiation with the detector array.

Abstract: An object within a region is exposed to a first beam of penetrating radiation. The first beam of penetrating radiation is sensed on a side opposite the region from a source of the first beam. An attenuation of the first beam caused by passing the first beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of a second of beam of penetrating radiation is adjusted based on the determined attenuation.

Abstract: According to one embodiment of a substrate measuring method, a shape of a unit structure is measured by making an electromagnetic wave incident on a periodical structure and detecting a scattered electromagnetic wave. Measurement conditions are determined through calculation of a scattering profile representing the distribution of scattering intensities of the electromagnetic wave and optimization corresponding to a comparison result obtained by comparing the scattering profile every time a value of a parameter of attention is changed.

Abstract: An imaging system and method for producing an image based on primary radiation. A separate image based solely on scattered radiation may also be obtained and may be of practical interests. The separation of primary and scattered radiation is achieved by utilizing a small beam exposure and a cone beam exposure, then the primary and scatter images are reconstructed based on a pencil beam model or from a Monte Carlo method. Other embodiments disclosed include two-layer detector arrays or volumetric detector arrays that measure the relationship between the dose and the position, from which the primary and scattered radiation can be extracted. In addition, by limiting a readout time of a detector, primary radiation component may be read because of a delay in the scattered radiation.

Abstract: There is provided a radiographic imaging device including: a radiation source that irradiates radiation generated by inverse Compton scattering; a first grating at which first members that diffract or absorb radiation are formed side by side such that pitches thereof are larger where distances from a center position of the radiation irradiated from the radiation source are larger, the first grating diffracting or absorbing radiation irradiated from the radiation source with the first members; a second grating that is disposed at a position at which Talbot interference is produced by the radiation diffracted or absorbed by the first grating, and at which second members that absorb radiation are formed side by side such that pitches thereof are larger where distances from the center position of the radiation irradiated from the radiation source are larger; and a radiation detector that detects radiation that has passed through the second grating.

Abstract: Systems and methods for inspecting an object with a scanned beam of penetrating radiation. Scattered radiation from the beam is detected, in either a backward or forward direction. Characteristic values of the scattered radiation are compared to expected reference values to characterize the object. Additionally, penetrating radiation transmitted through the inspected object may be combined with scatter information. In certain embodiments, the inspected field of view is less than 0.1 steradians, and the detector is separate from the source of penetrating radiation and is disposed, with respect to the object, such as to subtend greater than 0.5 steradians in the field of view of the object.

Abstract: There is provided a surface microstructure measurement method, a surface microstructure measurement data analysis method, and an X-ray scattering measurement device which can accurately measure a microstructure on a surface and which can evaluate a three-dimensional structural feature. In the surface microstructure measurement method, the specimen surface is irradiated with X-ray at a grazing incident angle and a scattering intensity is measured; a specimen model with a microstructure on a surface in which one or more layers is formed in a direction perpendicular to the surface and unit structures are periodically arranged in a direction parallel to the surface within the layers is assumed; a scattering intensity of X-ray scattered by the microstructure is calculated in consideration of effects of refraction and reflection caused by the layer; and the scattering intensity of X-ray calculated by the specimen model is fitted to the measured scattering intensity.

Abstract: An apparatus for analyzing bacteria is described that includes an analytic sample preparation section for preparing an analytic sample by treating a specimen so as to generate a morphological difference between Gram-negative bacteria and Gram-positive bacteria, a detector for detecting optical information from each particle contained in the analytic sample and an analyzing section for detecting Gram-positive bacteria contained on the basis of the detected optical information. A method for analyzing bacteria is also described.

Abstract: Methods and systems for detecting potential items of interest in target samples, using nuclear resonance fluorescence, utilize incident photon spectra that are narrower than traditional bremsstrahlung spectra but overlap nuclear resonances in elements of interest for purposes of detection, such as but not limited to the detection of threats in luggage or containers being scanned.

Abstract: Presented is a system and method for verifying the authenticity of a part using non-destructive backscattered X-rays. The method uses an identification tag embedded in the part that when illuminated by X-rays returns backscattered radiation that is detected and used to authenticate the part. The system comprises a source of low energy X-rays that irradiate a part, a detector for detecting backscattered radiation returned from the part, and a means for determining the presence of an authentication tag in the part. In embodiments, the system and method use a tag made of a material that returns a high amount of backscattered radiation thereby providing a high level of contrast in comparison with the part. In embodiments, the placement of the tag in the part, the geometry of the tag, and coding in the tag are used to authenticate the part.

Abstract: A X-ray scattering measurement device and measurement method can measure, with high resolution, the intensity of X-rays which have undergone small-angle scattering and diffraction with reflection geometry and can easily and accurately measure a microstructure on the surface of a sample. The X-ray scattering measurement device is suitable for microstructural measurement on the surface of a sample includes an X-ray source that generates an X-ray; a first mirror and a second mirror that continuously reflect the generated X-ray; a sample stage that supports the sample; and a two-dimensional detector that detects the X-ray scattered on the surface of the sample. The first mirror focuses the generated X-ray onto the two-dimensional detector within a plane parallel to the surface of the sample, and the second mirror focuses the X-ray reflected by the first mirror onto the surface of the sample within a plane perpendicular to the surface of the sample.

Abstract: A calibration technique is provided that utilizes a standard sample that allows for calibration in the wavelengths of interest even when the standard sample may exhibit significant reflectance variations at those wavelengths for subtle variations in the properties of the standard sample. A second sample, a reference sample may have a relatively featureless reflectance spectrum over the same spectral region and is used in combination with the calibration sample to achieve the calibration. In one embodiment the spectral region may include the VUV spectral region.

Abstract: The present invention relates to the field of x-ray imaging. More particularly, embodiments of the invention relate to methods, systems, and apparatus for imaging, which can be used in a wide range of applications, including medical imaging, security screening, and industrial non-destructive testing to name a few.

Abstract: A two-dimensional x-ray scattering camera includes a source, an optic, a detector, and a pair of collimating blocks. The source emits x-ray beams that are reflected by the optic towards a sample. The detector detects scattering from the sample, the pair of collimating blocks is positioned between the optic and the detector to collimate the beam. A bottom surface of one block is substantially parallel a top surface of the other block, and the blocks are rotatable relative to the beam about a pivot. The system forms a two-dimensional beam that is symmetric about the primary beam axis at the detector position, regardless how the beam is collimated by the collimating blocks. The system therefore eliminates smearing and can be used for anisotropic small angle scattering at high resolution and low Qmin.

Abstract: An x-ray source emits a cone beam a rapidly rotating, x-ray-opaque disc with four narrow radial slots. The slots break the cone beam into fan beams that are emitted to an x-ray-opaque plate with a narrow slit. As each fan beam moves across the plate, the slit produces a scanning x-ray pencil beam. The backscatter detector is mounted adjacent to the plate and has a slightly larger slit that is aligned with the plate slit. The pencil beam enters the object space through the detector slit. The pencil beam moves rapidly in a line across the object space, 20 cm in 0.1 second. Simultaneously, the assemblage of x-ray source, disc, plate, and detector moves slowly in the x direction at 1 mm in 0.05 second. Thus, the raster scan of the 20 cm×20 cm region is accomplished in 10 seconds.

Abstract: Methods and systems for inspecting objects are disclosed. A portable X-ray backscatter imaging system includes a microfocus X-ray tube to emit X-rays at an object under inspection. A track system rasters the microfocus X-ray tube to inspect the object. A portable hood may enclose the microfocus X-ray tube and the track system against the object A rotation mechanism rotates the microfocus X-ray tube to angle the emitted X-rays at the object. A plurality of solid state detectors receive scattered X-rays to generate an image of the object.

Abstract: Systems, methods and computer program products for the multi-modal detection of particles are described herein. An embodiment of the present invention is a particle detector that includes a first chamber wherein analyte particles are subjected to a first particle detection mechanism, and a second chamber coupled to the first chamber, wherein the analyte particles are subjected to a second particle detection mechanism, and wherein the detection characteristics of second particle detection mechanism are orthogonal to detection characteristics of the first particle detection mechanism.

Abstract: An image processing apparatus includes a first spectrum estimating unit for reading the image information from a storage unit and estimating a spectrum of an object based on the read image information; a dye amount estimating unit for estimating dye amounts included in the object using the estimated spectrum; a second spectrum estimating unit for synthesizing a first spectrum using the estimated dye amounts; a spectrum subtractor for calculating a difference spectrum by subtracting the first spectrum from the spectrum; a dye amount correcting unit for correcting at least a part of the estimated dye amounts; a third spectrum estimating unit for synthesizing a second spectrum using the corrected dye amount; a spectrum adder for synthesizing a third spectrum by adding the second spectrum and the difference spectrum; and an image synthesizer for synthesizing a display image from the third spectrum.

Abstract: An incident X-ray is emitted in a wide angular sector toward an amorphous material specimen which backscatters the X-rays. The method comprises: a step of recording experimental photon intensity measurements as a function of the angle of incidence; a step of correcting the experimental intensity, taking into account at least the absorption phenomena inside the specimen dependent on the penetration length l of the incident wave inside the specimen before reflection; a normalization step referring the corrected intensity arising from the experimental intensity to an electron intensity according to a normalization coefficient (?); a step of calculating a discretized function Q.

Abstract: An object within a region is exposed to a first beam of penetrating radiation. The first beam of penetrating radiation is sensed on a side opposite the region from a source of the first beam. An attenuation of the first beam caused by passing the first beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of a second of beam of penetrating radiation is adjusted based on the determined attenuation.

Abstract: A system and methods for characterizing an inspected object on the basis of attenuation between identified regions of scattering and a plurality of detectors. An incident beam of substantially monochromatic penetrating radiation is generated by a source, which may be a radioactive source. The incident beam is characterized by a propagation axis and a source energy. Radiation scattered by the object is detected by means of a plurality of detector elements disposed about the beam of penetrating radiation, each detector element generating a detector signal characterizing a detected energy of scattered radiation. The detector signal provides for determining a displacement for each scattering point of the object relative to a fiducial position on the propagation axis of the incident beam, based upon the detected energy of the scattered radiation.

Abstract: According to one embodiment, a pattern measuring method includes: irradiating, from a plurality of different incident directions, electromagnetic waves on a periodical structure pattern in which a plurality of patterns are periodically arrayed and partially overlap one another; detecting the electromagnetic waves scattered by the periodical structure pattern and detecting scattering profiles of the electromagnetic waves; and measuring, based on the detected scattering profiles, a pattern shape of the periodical structure pattern. Each of the different incident directions is an incident direction in which the patterns included in the periodical structure pattern do not partially overlap each other.

Abstract: The broadening of the lines in NRF from an isotope that is part of a material may be due to several causes: the temperature of the material, the molecular structure of the material and the crystalline structure of the material. By measuring the broadening caused by the molecular structure and the crystalline structure the material itself can be identified. The exact energy of the lines in NRF may also depend on the nature of the crystalline and molecular structure of the material. By measuring the changes in the energy of the NRF lines caused by the structure of the material the material itself may be identified. These techniques provide a “fingerprint” of the molecule or crystal that is involved. The fingerprint information may be used to determine a potential threat.

Abstract: An object within a region is exposed to a first beam of penetrating radiation. The first beam of penetrating radiation is sensed on a side opposite the region from a source of the first beam. An attenuation of the first beam caused by passing the first beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of a second of beam of penetrating radiation is adjusted based on the determined attenuation.

Abstract: An imaging system includes a radiation source (110) that emits radiation that traverses an examination region and a detector (116) that detects radiation traversing the examination region and a subject disposed therein, and produces a signal indicative of the energy of the detected radiation. A data selector (122) energy discriminates the signal based on an energy spectra setting corresponding to first and second spectral characteristics of a contrast agent administered to the subject, wherein the contrast agent has a first attenuation spectral characteristic when attached to the target and a second different spectral characteristic when not attached to the target. A reconstructor (134) reconstructs the signal based on the first and second spectral characteristics and generates volumetric image data indicative of the target.

Abstract: A method includes generating a plurality of scatter distributions based on geometric models having different object to detector distances, determining an imaged object to detector distance, and identifying a scatter distribution of the plurality of scatter distributions having a object to detector distance that corresponds to the imaged object to detector distance. The method also includes employing the identified scatter distribution to scatter correct projection data corresponding to the imaged object. Another method includes generating an estimate of wedge scatter by propagating a predetermined wedge scatter profile through an intermediate reconstruction of an object; and employing the estimate to wedge scatter correct the projection data.

Abstract: A vertical/horizontal small angle X-ray scattering apparatus, for enabling plural numbers of X-ray diffraction measurements, such as, transmission small angle X-ray diffraction, reflection small angle scattered X-ray diffraction, and in-plane X-ray diffraction, etc.

Abstract: A detection system includes a multi-focus radiation source configured to generate X-ray radiation and a primary collimator defining a first row of apertures and a second row of apertures. The first row of apertures forms first X-ray beams within a first plane from the X-ray radiation, and the second row of apertures forms second X-ray beams within a second plane from the X-ray radiation. The first plane is different than the second plane. The detection system further includes a scatter detector including a first row of scatter detector elements and a second row of scatter detector elements. The first row of scatter detector elements is configured to detect scattered radiation from the first X-ray beams, and the second row of scatter detector elements is configured to detect scattered radiation from the second X-ray beams.

Abstract: The different advantageous embodiments provide a system for identifying a likelihood of detecting objects with a backscatter x-ray system comprising a structure having a number of objects, a plurality of databases, and a processor unit configured to execute a detection analysis process. The processor unit executes the detection analysis process to identify the number of objects, identify a number of densities associated with each of the number of objects, determine a likelihood of detecting each of the number of objects with the backscatter x-ray system, and generate a three-dimensional diagram of the likelihood of detecting each of the number of objects.

Abstract: Apparatus and methods for detector scatter recovery for positron emission tomography systems are provided. One method includes identifying detected gamma events in different detector units of a nuclear medicine (NM) imaging detector and determining whether the detected gamma events occurred within a predetermined time period and have a summed energy of at least a predetermined level to define gamma events for reconstitution. The method further includes reconstituting the defined gamma events into single valid gamma events.

Abstract: This invention provides a scanning system for scanning an object in a scanning zone. The scanning system includes both a radiation source arranged to irradiate the object with radiation having a peak energy of at least 900 keV and a scatter detector arranged to detect radiation scattered from the object wherein the radiation source is arranged to irradiate the object over a plurality of regions to be scanned within a single irradiation event. The scatter detector includes a plurality of detection elements, each detection element being arranged to detect scattered radiation from a predefined part of the scanning zone and a signal processor arranged to calculate scatter intensity across the plurality of detector elements.