Abstract: Methods for generating a multiple-energy X-ray pulse. A beam of electrons is generated with an electron gun and modulated prior to injection into an accelerating structure to achieve at least a first and specified beam current amplitude over the course of respective beam current temporal profiles. A radio frequency field is applied to the accelerating structure with a specified RF field amplitude and a specified RF temporal profile. The first and second specified beam current amplitudes are injected serially, each after a specified delay, in such a manner as to achieve at least two distinct endpoint energies of electrons accelerated within the accelerating structure during a course of a single RF-pulse. The beam of electrons is accelerated by the radio frequency field within the accelerating structure to produce accelerated electrons which impinge upon a target for generating Bremsstrahlung X-rays.

Abstract: Systems and methods for detecting clandestine fissile or radioactive material on the basis of emitted radiation and particles (such as neutrons and alpha particles) arising from within the material. Emission by the fissile or radioactive material is detected in conjunction with a conventional x-ray imaging system that includes an external source of illuminating penetrating radiation, at least one detector configured to detect at least the penetrating radiation and to generate a detector signal, and a processor configured as a detector signal discriminator to generate an output indicating whether the detector signal is triggered by an origin other than illuminating penetrating radiation. Active and passive modes of detection are described by some embodiments. Other embodiments are directed toward neutron detection, gamma ray detection with energy resolution, and designs of detectors to enhance the detection of clandestine nuclear material.

Abstract: 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.

Abstract: Methods for generating a multiple-energy X-ray pulse. A beam of electrons is generated with an electron gun and modulated prior to injection into an accelerating structure to achieve at least a first and specified beam current amplitude over the course of respective beam current temporal profiles. A radio frequency field is applied to the accelerating structure with a specified RF field amplitude and a specified RF temporal profile. The first and second specified beam current amplitudes are injected serially, each after a specified delay, in such a manner as to achieve at least two distinct endpoint energies of electrons accelerated within the accelerating structure during a course of a single RF-pulse. The beam of electrons is accelerated by the radio frequency field within the accelerating structure to produce accelerated electrons which impinge upon a target for generating Bremsstrahlung X-rays.

Abstract: X-ray inspection of moving cargo based on acquiring multiple image lines at one time or substantially at one time. An X-ray source with multiple-beam electron beam targets creates multiple parallel X-ray fan beams. X-ray inspection systems and methods employ such multiple-beam sources for purposes of inspecting fast moving cargo.

Abstract: A method for imaging a target with an x-ray scatter apparatus. Air scatter from air intervening between the x-ray scatter apparatus and a target overwhelms x-ray scatter from the target in that x-ray scatter from a position on the target is no more than 10% of the x-ray scatter due to intervening air scatter that reaches at least one point in the detector plane of the x-ray scatter apparatus. The target is illuminated with a beam of x-rays scanned across the target, and x-rays scattered by the target are detected using a detector with a centroid displaced with respect to the beam axis by at least five feet. The detector signal is then processed to generate an image of the target. The beam of x-rays may be unshielded, and/or the detector may be uncollimated.

Abstract: An x-ray tube for generating a sweeping x-ray beam. A cathode is disposed within a vacuum enclosure and emits a beam of electrons attracted toward a rotating anode. The rotating anode is adapted for rotation with respect to the vacuum enclosure about an axis of rotation. At least one collimator opening or aperture corotates with the rotating anode within the vacuum enclosure, such that a swept x-ray beam is emitted.

Abstract: Methods and apparatus for determining the distance to a specified point or distances between specified points on one or more objects, where the specified points are obscured behind an opaque barrier and cannot be viewed. Specified points are illuminated with penetrating radiation from two or more successive locations, and scattered radiation from the specified points is detected, and distance is calculated based on illumination angles. The apparatus has a source of penetrating radiation, a beam scanner for directing the penetrating radiation, a detector for detecting scattered radiation, and a processor for calculating the distance.

Abstract: An adjustable collimator for shaping a beam of particles, such as for purposes of inspecting contents of a container. The adjustable collimator has an obscuring element substantially opaque to passage of the particles in a propagation direction that is radial with respect to the axis of rotation of a ring of apertures. A gap in the obscuring element may be characterized by a length taken along a long dimension and a jaw spacing taken along narrow dimension, and at least one of the length of the gap and the jaw spacing is subject to adjustment, either manual or automatic. The adjustable collimator may be disposed either inside or outside the ring of apertures, and, in some embodiments, the jaw spacing may be a function of distance along the long dimension relative to an edge of the gap.

Abstract: A detector and methods for inspecting material on the basis of scintillator coupled by wavelength-shifting optical fiber to one or more photo-detectors, with a temporal integration of the photo-detector signal. An unpixelated 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. This geometry provides for efficient and compact detectors, enabling hitherto unattainable geometries for backscatter detection and for energy discrimination of incident radiation. Additional energy-resolving transmission configurations are enabled as are skew- and misalignment compensation.

Abstract: A system for producing a controllable beam of radiation is controllable electronically, and includes no parts that must move relative to one another while in operation to form the beam. The direction and cross-section of the beam may be controlled electronically by controlling an electron beam. Various embodiments provide an X-ray collimator that allows forming a scanning X-ray beam of desired size and flux independently of the aperture material thickness without requiring movement of the aperture or physical components that create the aperture. Some embodiments provide an X-ray collimator that allows forming a scanning X-ray beam of desired size and flux independently of the beam angle.

Abstract: An x-ray inspection system using backscatter of an x-ray beam emitted through a scan panel contiguous with, but of a material distinct from, an enclosure that contains an x-ray source by which the x-ray beam is generated. The scan panel is contoured in such a manner as to be visibly blended with a shape characterizing the enclosure. In some embodiments, the beam traverses multiple scan panels, where one or more of the scan panels may be selected for beam filtration properties. The scan panel may be disposed interior to a sliding door, and may be structured to serve as a scatter shield.

Abstract: A system for producing a controllable beam of radiation is controllable electronically, and includes no parts that must move relative to one another while in operation to form the beam. The direction and cross-section of the beam may be controlled electronically by controlling an electron beam. Various embodiments provide an X-ray collimator that allows forming a scanning X-ray beam of desired size and flux independently of the aperture material thickness without requiring movement of the aperture or physical components that create the aperture. Some embodiments provide an X-ray collimator that allows forming a scanning X-ray beam of desired size and flux independently of the beam angle.

Abstract: An x-ray tube for generating a sweeping x-ray beam. A cathode is disposed within a vacuum enclosure and emits a beam of electrons attracted toward an anode. The anode is adapted for rotation with respect to the vacuum enclosure about an axis of rotation. At least one collimator opening corotates with the anode within the vacuum enclosure, such that a swept x-ray beam is emitted.

Abstract: A versatile beam scanner for generating a far-field scanned pencil beam, and, alternatively, a far-field pencil beam. An angle selector limits the angular extent of an inner fan beam emitted by a source of penetrating radiation. The source and angle selector may be translated, along a direction parallel to a central axis of a multi-aperture unit, in such a manner as to generate a scanned far-field pencil beam, when rings of apertures are interposed between the source and an inspected target, or, alternatively, a far-field fan beam, when no ring of apertures is interposed.

Abstract: Apparatus for interrupting and/or scanning a beam of penetrating radiation, such as for purposes of inspecting contents of a container. A source, such as an x-ray tube, generates a fan beam of radiation effectively emanating from a source axis, with the width of the fan beam collimated by a width collimator, such as a clamshell collimator. An angular collimator, stationary during the course of scanning, limits the extent of the scan, and a multi-aperture unit, such as a hoop, or a nested pair of hoops, is rotated about a central axis, and structured in such a manner that beam flux incident on a target is conserved for different fields of view of the beam on the target. The central axis of hoop rotation need not coincide with the source axis.

Abstract: A mobile scanning system and methods for inspecting contents of a container. Multiple detector plates are arrayed along an arcuate member coupled to a conveyance with wheels, capable of road travel. A source generates high-energy penetrating radiation that irradiates each of the detector plates from a single position. The arcuate member is disposed, during the course of operation of the system, in a vertical plane. The system has one actuator for rotating the arcuate member about a horizontal pivot into a horizontal plane, and a second actuator for further rotating the arcuate member, once rotated into the horizontal plane, about a vertical pivot, so that the arcuate member is contained, for purposes of transport, entirely within a volume defined by a rectangular prism that does not extend horizontally outward from the conveyance beyond any of its wheels.

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: 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.