Abstract: A method of operating an x-ray fluorescence (XRF) analyzer to automatically suppress sum-peaks is disclosed. The method includes irradiating a sample to acquire an initial energy spectrum. The energy spectrum is processed to identify a sum-peak that interferes with a characteristic fluoresced peak of an element of interest. A filter is positioned in the emitted radiation path to attenuate radiation that contributes to the identified sum-peak, and a filtered energy spectrum is acquired. In certain embodiments, the filtered energy spectrum is acquired only when a limit of detection (LOD) of an element of interest calculated from the initial energy spectrum does not satisfy a targeted objective.

Abstract: A thermal neutron monitor includes at least one neutron scintillator sheet interposed between light guides. Scintillation light emitted in opposite transverse directions is captured by the light guides and conveyed to a common detector. The sandwiched geometry of the monitor avoids the need to provide multiple detectors and permits construction of a relatively inexpensive, compact monitor.

Abstract: An apparatus and method are disclosed for localizing an element of interest in a sample by comparing XRF spectra acquired from at least two distinct but overlapping inspection volumes. The inspection volumes are varied by changing the geometry of the exciting x-ray and/or fluoresced x-ray beam(s), which may be accomplished by repositioning multi-apertured collimators. Comparison of the XRF spectra acquired from different inspection volumes provides an indication as to whether the element of interest (e.g., lead) is present in a coating layer, in the underlying bulk material, or in both.

Abstract: A thermal neutron monitor includes at least one neutron scintillator sheet interposed between light guides. Scintillation light emitted in opposite transverse directions is captured by the light guides and conveyed to a common detector. The sandwiched geometry of the monitor avoids the need to provide multiple detectors and permits construction of a relatively inexpensive, compact monitor.

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: 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: 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 the total beam fluence 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: An apparatus and method are disclosed for localizing an element of interest in a sample by comparing XRF spectra acquired from at least two distinct but overlapping inspection volumes. The inspection volumes are varied by changing the geometry of the exciting x-ray and/or fluoresced x-ray beam(s), which may be accomplished by repositioning multi-apertured collimators. Comparison of the XRF spectra acquired from different inspection volumes provides an indication as to whether the element of interest (e.g., lead) is present in a coating layer, in the underlying bulk material, or in both.

Abstract: An apparatus and method are disclosed for localizing an element of interest in a sample by comparing XRF spectra acquired from at least two distinct but overlapping inspection volumes. The inspection volumes are varied by changing the geometry of the exciting x-ray and/or fluoresced x-ray beam(s), which may be accomplished by repositioning multi-apertured collimators. Comparison of the XRF spectra acquired from different inspection volumes provides an indication as to whether the element of interest (e.g., lead) is present in a coating layer, in the underlying bulk material, or in both.

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 method is provided for screening lead concentration compliance of objects, particularly consumer products such as toys, using x-ray fluorescence (XRF) analysis. The measured intensity ratio of the characteristic L? and L? x-rays of lead provides an indication of whether the lead is located primarily in a coating (e.g., paint) layer on the object, or in a thin or thick bulk material. If the intensity ratio indicates that the lead is located in a coating layer or distributed in a thin bulk material, an areal density of lead is determined from at least one of the characteristic x-ray intensities, and the measured areal density is compared to specified lower and upper limits to determine whether the object is unambiguously compliant, unambiguously non-compliant, or indeterminate.

Abstract: Methods and apparatus for adapting the shaping time and/or other pulse processing parameters of an x-ray detector (114) in accordance with the elemental composition of a sample and/or energy resolving requirements. X-rays (104) are directed from a source (102) onto a sample (110) and the radiation (108) responsively emitted from the sample (e.g., fluoresced radiation characteristic of the sample's elemental composition) and detected by an x-ray detector (114) that generates pulses representative of the energy and intensity of the incident radiation. Based upon initial analysis of elemental composition, the shaping time and/or other pulse processing parameter (s) are set to optimize count rate subject to constraints of energy resolution in a spectral region of interest.

Abstract: A hand-held, self-contained x-ray fluorescence (XRF) analyzer produces a small x-ray spot on a sample to interrogate the elemental composition of a sample region of millimeter-size characteristic dimension. The analyzer includes a collimator for aiming an x-ray beam toward a desired location on the sample and for determining the size of the spot produced on the sample. The analyzer may include a digital camera oriented toward the portion of the sample that is, or would be, interrogated by the x-ray spot to facilitate aiming the analyzer. The analyzer may generate a reticule in a displayed image to indicate the portion of the sample that is, or would be, illuminated by the x-ray beam. The analyzer may automatically annotate the image of the sample with text or graphics that contain information about the analyzed sample. The image may be stored in the hand-held analyzer or provided for external storage or display.

Abstract: A method, instrument, and computer program software product for characterizing a sample with respect to the presence of a specified element, either as a constituent of a surface layer or of the bulk of the sample. Intensities of fluorescent emission at two characteristic emission lines are compared to establish whether the specified element is disposed above the bulk of the sample. In the case where the specified element is disposed above the bulk of the sample, an areal density of the specified element is determined, whereas in the case where the specified element is disposed within the bulk of the sample, a volumetric concentration of the specified element within the sample is determined.

Abstract: Methods and apparatus for analyzing a test sample using complementary techniques, such as x-ray fluorescence (XRF) and optical emission spectroscopy (OES), are disclosed for registering two or more test instruments, in relation to the test sample, such that each of the instruments analyzes substantially the same region as is analyzed by the other instrument(s), and for communicating analytical results between or among the instruments, or between the instruments and another component, to enable one or more of the instruments, or the other component, to combine the results and, thereby, more completely and accurately determine the composition of the test sample. Such registration and communication enables, for example, separate XRF and OES instruments to collectively determine the composition of the test sample, including the absolute amounts of light and heavy elements in the test material.

Abstract: A hand-held, self-contained x-ray fluorescence (XRF) analyzer produces a small x-ray spot on a sample to interrogate the elemental composition of a sample region of millimeter-size characteristic dimension. The analyzer includes a collimator for aiming an x-ray beam toward a desired location on the sample and for determining the size of the spot produced on the sample. The analyzer may include a digital camera oriented toward the portion of the sample that is, or would be, interrogated by the x-ray spot to facilitate aiming the analyzer. The analyzer may generate a reticule in a displayed image to indicate the portion of the sample that is, or would be, illuminated by the x-ray beam. The analyzer may automatically annotate the image of the sample with text or graphics that contain information about the analyzed sample. The image may be stored in the hand -held analyzer or provided for external storage or display.

Abstract: A method for classifying a sample based upon a complete spectral analysis. The sample is illuminated with penetrating radiation and an initial complete spectral analysis is performed based on spectral resolution of resonant fluorescence lines emitted at the surface, or within the volume, of the sample. If the initial complete spectral analysis yields the composition of the sample to within acceptable limits, analysis values are output to the user. Otherwise, further analysis, informed by the results if the initial complete spectral analysis, is performed.

Abstract: An apparatus and method are disclosed for localizing an element of interest in a sample by comparing XRF spectra acquired from at least two distinct but overlapping inspection volumes. The inspection volumes are varied by changing the geometry of the exciting x-ray and/or fluoresced x-ray beam(s), which may be accomplished by repositioning multi-apertured collimators. Comparison of the XRF spectra acquired from different inspection volumes provides an indication as to whether the element of interest (e.g., lead) is present in a coating layer, in the underlying bulk material, or in both.

Abstract: A method is provided for screening lead concentration compliance of objects, particularly consumer products such as toys, using x-ray fluorescence (XRF) analysis. The measured intensity ratio of the characteristic L? and L? x-rays of lead provides an indication of whether the lead is located primarily in a coating (e.g., paint) layer on the object, or in a thin or thick bulk material. If the intensity ratio indicates that the lead is located in a coating layer or distributed in a thin bulk material, an areal density of lead is determined from at least one of the characteristic x-ray intensities, and the measured areal density is compared to specified lower and upper limits to determine whether the object is unambiguously compliant, unambiguously non-compliant, or indeterminate.

Abstract: Multiple energy sources, such as a laser and electrical current, are employed, in close coordination, spatially and temporally, to clean a sample, vaporize its material and excite vapor atoms for the purpose of atomic emission spectroscopy. These methods permit better monitoring and control of the individual processes in real time, lead to higher consistency and higher quality optical emission spectra, and enhance the measurements of non-conducting solids, liquids and gases. Additionally, a portable instrument is provided with both laser source and spectrometer optically coupled to a hand-holdable unit.