Abstract: A method and arrangement for measuring the moisture content of a flow of wood chips, through which collimated gamma radiation is directed attenuation of which in the flow of wood chips is measured. The flow of wood chips is shaped by transporting it on a trough-shaped conveyor in such a way that the length of a ray can be determined. The moisture content can be calculated on the basis of the proportion of gamma radiation passing through the flow of wood chips and the flow's thickness, as well as on the basis of the previously determined air content of the flow of wood chips.

Abstract: An apparatus for measuring the pulse transmission spectrum of elastically scattered quantities includes at least one diaphragm displaceable in a y-direction for switching between fine and coarse local resolution of the examined partial volumes of an examination object, wherein the diaphragm narrows the effective ray width transversely of a scanning direction, and a diaphragm system displaceable in a x-direction for limiting and extension of the partial volume in a z-direction, wherein the diaphragm system includes at least two circular ring diaphragms arranged one above the other and identical with respect to their circular ring structure, and wherein the circular ring diaphragms are arranged at a relative offset for reducing an effective imaging slot width or a detector slot width.

Abstract: An optical sample X-ray testing apparatus including an X-ray source which is configured to radiate X-rays including a group of line spectra. At least one line spectrum selecting device is provided between the X-ray source and an optical sample and configured to direct substantially one line spectrum among the group of line spectra from the X-ray source toward the optical sample. An optical characteristics finding device is configured to find optical characteristics of the optical sample based on radiation of the substantially one line spectrum through the line spectrum selecting device onto the optical sample.

Abstract: A structural system for accurately reproducible in situ x-ray studies of operating rechargeable electrochemical battery cell electrode components comprises an hermetically sealed cell component enclosure incorporating an x-ray transmissive window member of beryllium or the like. A research embodiment of the system comprises means for rapidly and consistently interchanging electrode compositions for operative comparison and evaluation, while a laminated cell system embodiment enables accurate testing of electrode components in commercial configurations such as unitary polymeric Li-ion battery cells.

Abstract: An X-ray source is provided for delivering a high intensity X-ray beam with a predefined energy level of monochromatization, intensity and spatial distribution to a desired region of a sample. The source includes a linear accelerator with a thin anode 4, an electron trap 5 for separating an electron beam from an X-ray beam and conditioning optics which direct, shape and monochromatize the X-ray beam. The conditioning optics include a housing 8 within which are contained entrance slits, multi layer Kirkpatrick-Baez mirrors, exit slits, and a stop diaphragm. The invention also include a method of generating X-rays and a method of using them.

Abstract: The invention relates to the mammography devices based on registration of a reduced-angle coherently scattered radiation when an object is rayed by a penetrating radiation. Registration of the radiation coherently scattered by an object allows to produce an image of an object in the form of distribution of its structural characteristics. The device comprises a system for forming a directed on a tested object, narrow small-divergence beams, or a beam, having the same characteristics, and a system for extracting the radiation that is coherently scattered in small angles by an object. The invention proposes versions of a device that also provide for registration of the radiation passed through an object to make allowance for its thickness so that to obviate the necessity to compress the breast. The device allows to carry out relative movements of an object and system of irradiation-registration, as well as irradiate an object at different angles and by a number of radiation sources simultaneously.

Abstract: An inspection system for inspecting a moving vehicle and for detecting material disposed within the vehicle. The system has a source for providing a generally horizontally pointing beam of penetrating radiation of specified cross-section so as to illuminate vehicles driven alongside the source of radiation. A detector arrangement, disposed between the source of radiation and the moving vehicle detects radiation from the beam scattered by any material disposed on the underside of the moving vehicle and generates a scattered radiation signal that may be used for characterizing the material disposed within the vehicle.

Abstract: An apparatus and method for detecting explosive material uses dual energy information of an X-ray scan of the material. The object in question is located within a region which includes extraneous objects. The region is scanned by an X-ray radiation source which alternately emits radiation at two different energy levels, and a detector array collects the radiation after passing through the material. A reconstruction computer generates a CT image from the series of projections corresponding to one of the two energy levels. A spatial analysis computer analyzes the CT image and determines the projection which includes only the object in question (a clear-path projection) or the projection which includes the object in question along with the fewest extraneous objects. A projection computer uses the high energy clear-path projection and the low energy clear-path projection to determine quantitative information relating to two physical characteristics of the object in question, for example atomic number and density.

Abstract: This invention provides a measurement device that includes both an X-ray reflectometer and a thermal or plasma wave measurement module for determining the characteristics of a sample. Preferably, these two measurement modules are combined into a unitary apparatus and arranged to be able to take measurements at the same location on the wafer. A processor will receive data from both modules and combine that data to resolve ambiguities about the characteristics of the sample. The processor can be part of the device or separate therefrom as long as the measurement data is transferred to the processor.

Abstract: A method for determining the material of a detected item in objects, especially explosives in luggage, using X-ray diffraction. In this method, wherein scatter radiation deflected at the crystal source of the material is measured and compared to characteristic energy spectra or diffraction spectra of the various explosives, the absorption by the material influences the X-ray diffraction spectrum, so that information is missing, and inaccurate conclusions may be drawn regarding the material. To improve this method, the primary beam of an X-ray source is used for measuring the absorption. The beam passes through the material, and, from the absorption, an average atomic number of the material is determined, and this information additionally is used in the comparison to known diffraction spectra.

Abstract: A hand holdable inspection device for three-dimensional inspection of a volume distal to a surface. The inspection device has a hand-holdable unit including a source of penetrating radiation for providing a beam of specified cross-section and a detector arrangement for detecting penetrating radiation from the beam scattered by the object in the direction of the detector arrangement and for generating a scattered radiation signal. Additionally, the inspection device has a controller for characterizing the volume based at least on the scattered radiation signal. The detector arrangement includes one or more backscatter detectors that may be disposed asymmetrically with respect to the beam and at differing displacements with respect to the surface.

Abstract: An inspection system is for inspecting an object with penetrating radiation. A source of penetrating radiation provides a beam of radiation. The beam alternates between a first beam shape and a second beam shape, the first and second beam shapes being coplanar. A first detector arrangement is for detecting penetrating radiation from a portion of the beam transmitted through the object and generating a transmitted radiation signal. A second detector arrangement is for detecting penetrating radiation from a portion of the beam scattered by the object and generating a scattered radiation signal. A processor determines at least one characteristic of the object based at least on the transmitted and scattered radiation signals.

Abstract: An inspection system for inspecting a vehicle moving at a grade of travel over a surface and for detecting material disposed within or on the underside of the vehicle. The system has a source for providing a generally upward or downward pointing beam of penetrating radiation of specified cross-section so as to illuminate vehicles driven above or below the source of radiation. A detector arrangement, disposed below the grade of travel, detects radiation from the beam scattered by any material disposed on the underside of the moving vehicle and generates a scattered radiation signal that may be used for characterizing the material disposed on the underside of the vehicle. Similarly, a detector arrangement disposed above the vehicle generates a scattered radiation signal that may be used for characterizing the material disposed within the vehicle.

Abstract: Evolutionary algorithms are used to find a global solution to the fitting of experimental X-ray scattering data to simulated models. A recombination operator combines two or more parameter vectors from one iteration of simulated scattering data to form a new parameter vector for the next iteration, in a manner such that there is a high probability that the new parameter will better fit the experimental data than any of the parent parameters. A mutation operator perturbs the value of a parent vector, to permit new regions of the error function to be examined, and thereby avoid settling on local minima. The natural selection guarantees that the parameter vectors with the best fitness will be propagated into future iterations.

Abstract: A system and method for inspecting an object, where both a fan beam and a pencil beam of penetrating radiation are used to illuminating the object concurrently. Both beams may be derived from a single source of penetrating radiation. The pencil beam is noncoplanar with the fan beam and may be scanned with respect to the object. Radiation scattered from the pencil beam within the object is detected, and the scatter signal thus generated is used in conjunction with a transmission signal which characterizes attenuation of the fan beam by the object.

Abstract: An apparatus for analyzing substances within a breast is disclosed. The apparatus includes a breast positioning area and a beam forming apparatus having a geometry which forms breast penetrating radiation into at least one beam. A detector is configured to detect a scattering pattern of the portion of the breast which scatters radiation from the at least one beam when the breast is positioned within the breast positioning area.

Abstract: The present invention relates to a device for measuring density or determining the presence and the amount of materials of different density in an object to be measured, of a solid, liquid or gaseous material, said device comprising at least one source of radiation for emitting electromagnetic radiation, and at least one sensor for measuring the radiation intensity, so positioned as to absorb radiation form the source of radiation and being connected to a calculation unit. In accordance with the invention the device emits radiation of at least two wavelenghts and comprises measurement means for determination of the extension of the object between the source of radiation and the sensor. In addition, the invention relates to a method of measuring density, comprising radiating electromagnetic rays through an object to be measured and measuring the radiation intensity on the ray-exit side of the object to be measured.

Abstract: An X-ray inspection system comprises an X-ray source (1) disposed to irradiate an object to be inspected (4) with a beam of X-rays in the form of a fan project from the source (1) through the object (4), detection means (6) capable of discriminating between the intensitities of X-rays coherently scattered through the object (4) at different angles to produce an output signal dependent on the intensity of the X-rays scattered through each of those angles and analyzing means (not shown) operably connected to the detention means (6) to process the output signal to determine the presence of X-rays coherently scattered through one or more pre-determined angles. Collimination means (23) is provided between the detection means (6) and the object (4) and is adapted to pass only X-rays coherently scattered at the different angles from a limited voxel (volume element) depth central at point P. Movement at the collimator (23) along the direction of the beam together with translation of the object by e.g.

Abstract: X-ray diagnostic system. The system includes a source of x-rays which communicates with an x-ray beam concentrator spaced apart from the x-ray source and disposed for receiving x-rays from the x-ray source. An x-ray spectrometer is disposed for receiving x-rays from the concentrator. In a preferred embodiment, the concentrator is formed of a cylindrical spiral of a metal-coated plastic material having a surface for reflecting x-rays. In another embodiment, the concentrator includes a plurality of concentric nested cylinders of a metal-coated plastic material for reflecting x-rays. In yet another embodiment, the concentrator is a glass capillary bundle. The concentrator allows the spectrometer to be spaced away from the source of x-rays such as scanning electron microscope.

Abstract: A pencil beam of X-rays is scanned over the surfaces of the body of a person being examined as the person walks through the scanning apparatus. Specifically, a tracking assembly is employed to rotate the scanning plane through a tracking angle and in a direction progressing from the entrance to the exit of the portal, through which the person passes, in order to substantially track the person or body as it moves with respect to the system from the entrance to the exit X-rays that are scattered or reflected from the subject's body are detected by a detector assembly. The signal produced by this scattered X-ray detector in then used to modulate an image display device to produce an image of the subject and any concealed objects carried by the subject. The detector assembly is constructed in a configuration to automatically and uniformly enhance the image edges of low atomic number (low Z) concealed objects to facilitate their detection.

Abstract: This invention relates to improved sheet products and specifically to improved nonwoven sheet products made from highly oriented plexifilamentary film-fibril webs. The improved sheet products have high opacity and strength with a much wider range of porosity or Gurley Hill Porosity Values. In particular, sheet products made in accordance with the present invention have considerably higher Gurley Hill Porosity Values than similar weight sheet products subject to the same finishing treatments in accordance with prior known sheet materials. Similarly, sheet products made in accordance with the present invention can be made which have much lower Gurley Hill Porosity Values than prior sheet materials. The invention includes numerous methods and data characterizing the webs and sheets that form the improved sheet materials.

Abstract: The present invention relates to X-ray devices for the investigation of material structure, density and geometry of reflected surfaces by measuring reflected, diffracted or scattered radiation. These X-ray optical devices are especially useful for measuring polished surfaces with large reflective areas which are used in the electronics and the computer industry (wafers, memory discs), high precision mechanics and optics. The present invention describes a device which increases the accuracy and efficiency in which X-ray reflectometry measurements can be made in different parts of the X-ray spectral region. The main technical advantages of the invention are a two-fold reduction in the ultimate error of angular measurements in different spectral regions, and a decrease in the random errors associated with the intensity measurements that are observed which are due in part to a drift in the electric parameters of the device.

Abstract: A method of detecting an object in an examination zone is well-suited for detecting land mines buried in the soil. The mean atomic numbers of the object is different from that of the examination zone. The examination zone is irradiated by gamma radiation. The annihilation radiation thus generated is measured and evaluated. The gamma radiation, which is sufficiently strong to generate electron-positron pairs, amounts to less than 10 MeV. The radiation generated in the examination zone by the gamma radiation beam is detected by a plurality of detector elements, which are arranged in such a manner that they can always detect only a respective segment of the gamma radiation beam.

Abstract: An x-ray backscatter tomography system includes a collimated x-ray source for directing a collimated beam towards a target at a select position and orientation, a first detector array for measuring photons scattered at a selected first angle, and a second detector array for measuring photons scattered at a selected second angle different from the first angle. The system is also responsive to the first and second detectors for calculating the density and atomic number of the target.

Abstract: A method is disclosed for obtaining the density distributions of three-dimensional elements that compose objects or groups of objects, by examining the objects with beams of x-rays or gamma radiation that are transmitted through the object in a plurality of approximately parallel paths and measuring the intensity of the radiation, scattered approximately perpendicular to the parallel paths, in arrays of detectors around the object. The energy of the x-rays or gamma rays is such that dominant interaction in the object is Compton scattering. The density of each element is determined from the totality of measurements by standard mathematical tomographic or relaxation techniques of data manipulation.

Abstract: The invention is a detector for detection of concealed explosives, drugs and contraband using x-rays imaging and powder pattern techniques and ultrasonics. In case of inspection of carry-on baggage a combination of computer-aided x-ray transmission imaging and x-ray diffraction analysis is used to screen; confirm and localize threats. The x-ray transmission is used to segregate dense baggage and cargo which are inspected by x-ray backscatter imaging to identify suspicious objects. All suspicious objects are carefully analyzed by x-ray diffraction. In another embodiment a slow processing system uses diffraction for identification of threats and x-ray radiography for localization of the objects. In case of drugs concealed in compartments aboard marine vessels or air crafts a hand-held x-ray system is disclosed which can be used in three modes of operation: x-ray transmission, x-ray backscatter, or x-ray diffraction dependent on the architecture of the compartment.

Abstract: An apparatus and method for monitoring structural changes of an electrode in a rechargeable battery include an in situ x-ray study electrochemical cell holder (30) comprising top and bottom cell holder members (32, 34) including at least one beryllium window element (36) for transmission of diffractometer x-radiation. A rechargeable battery cell (43) mounted within the x-ray cell holder enclosure comprises an electrolyte/separator element (68) interposed between positive and negative electrodes (64, 66). A current collector element (70) formed of an electrically-conductive open-mesh grid is disposed between the positive electrode and the separator to enable ion-conducting contact of the electrode and separator while maintaining electrical continuity between the electrode and an external x-ray cell holder terminal (54).

Abstract: A method of determining the concentration of incombustible material in a predetermined volume of coal includes irradiating the volume with .gamma.-rays from a first source having a first, low energy; and simultaneously irradiating the volume with .gamma.-rays from a second source having a second, higher energy. Rays of back-scattered radiation from the irradiated volume are detected. An analogue signal for each ray that is detected is generated, an amplitude of said signal being representative of the energy of the ray. Each analogue signal is converted into an equivalent digital signal. For all values of signals in a predetermined range, the number of digital signals having the same value that are detected in a predetermined time period is determined and said signals of the same value are stored together to provide a frequency spectrum. The frequency spectrum is processed to provide the concentration of incombustible material in the volume.

Abstract: The invention is a method and apparatus for identifying and pinpointing the location of unwanted pieces of material or defects in, for example, de-boned poultry pieces. The poultry pieces to be inspected are carried on a conveyor and passed under an impinging collimated X-ray beam. The Rayleigh scattering resulting is detected and measured, as is the Compton back scattering and the data is processed in a processing unit to determine the location and type of foreign matter involved. The ratio of the Rayleigh and Compton scattering is also determined and used to verify the identity of the foreign material. Transmitted X-rays, i.e., radioscopy, are used to normalize the data, and to aid in a pinpointing of the location of the unwanted material.

Abstract: A technique for detecting explosives and other materials using resonance fluorescence, resonance absorption, and other electromagnetic processes with a continuous spectrum of photons is disclosed. The method is particularly attractive as a way to detect explosives at airports and other transporation terminals. According to one aspect of the invention, bremsstrahlung or other continuous-spectrum photon radiation in the appropriate energy ranges is made incident on a target (e.g., a piece of luggage or other container) to resonantly excite the atoms of the target. In one embodiment, the energies of the photons scattered directly from the target are detected and measured. These energies are characteristic of the nuclear species excited in the target, and thus the concentrations of these elements in the target can be determined. A high concentration of nitrogen and oxygen with a low concentration of carbon indicates practically without fail an explosive material.

Abstract: The concentrations of residual heavy metal contaminants in the particulate material in a slurry produced in a particulate material washing process are monitored on-line and can be used to control the washing process. In alternative embodiments of the invention, x-rays, thermal neutrons or laser beams are directed at the slurry as it flows through a flow cell to induce emission of secondary x-rays, gamma rays or light, respectively, characteristic of the heavy metal contaminants and constituents representative of the solids contents of the slurry. These characteristic energies are measured and used to determine the concentration in ppm of the residual heavy metal contaminants in the particulate material within the slurry.

Abstract: A device for measuring the pulse transfer spectrum of X-ray quanta, includes a polychromatic X-ray source and an energy-resolving detector device for the scattered X-ray quanta. A secondary diaphragm device, arranged between the examination zone in which the object whose pulse transfer spectrum is to be determined is situated, and the detector device ensure on the one that each detector element of the detector device can detect scattered radiation only at a comparatively accurately defined scatter angle, and that the scatter angles of the various detector elements do not excessively deviate from one another.

Abstract: A filter method and device for carrying out the method in conjunction with an X-ray system having a beam path for primary radiation between an X-ray source and an examination zone and a beam path for scattered radiation between the examination zone and a detector device, involve subtractive combination of first and second measurement signals produced by the detector device in response to scattered radiation received in first and second filter arrangements. For production of the first measurement signal a filter is arranged in the beam path for primary radiation and not in the beam path for scattered radiation, while for production of the second measurement signal a filter is arranged in the beam path for scattered radiation and not in the beam path for primary radiation. The latter filter consists of the same material as the filter used for the first measurement, and may be the same filter.

Abstract: A radioactive source holder for use with a NaI (TI) spectrometer for obtaining very low dose estimates in bone minerals in vivo, comprising a molybdenum tube, a gold insert within the tube, a blind hole within the insert for receiving the radioactive source, and an inner tube inserted into the blind hole for directing radiation from the source in a narrow cone, whereby the directing of radiation in the narrow cone minimizes spectrometer response to radiation which has been scattered by soft tissue overlying a bone.

Abstract: An apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam of gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite, releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: The invention relates to an apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam of gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite, releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: A method and apparatus are provided for performing non-invasive measurements, and in particular in vivo non-invasive measurements of the total body content of a particular element, or of the content of such elemetn in a particular body area, by use of resonant gamma ray detection. More particularly, gamma rays are generated at the resonant gamma absorption energy level for the element on which measurements are to be made and are passed through the portion of the patient's body for which measurements are to be made. Detected gamma rays passing through the patient's body may be utilized as an indication of the content of such element. The effect of non resonant gamma absorption may be subtracted by also passing gamma rays of non-resonant absorption energy through the same body part and utilizing detected gamma rays at this energy passing through the body to determine the non-resonant absorptions.

Abstract: An X-ray apparatus comprises a polychromatic X-ray source for generating a primary beam of small cross-section, an energy-sensitive detector arrangement for detecting the scattered radiation produced by elastic scattering processes in the primary beam, which detector arrangement comprises a plurality of detector elements which are arranged on rings concentric with the primary beam, and a collimator arrangement which is arranged between the X-ray source and the detector arrangement and which encloses the primary beam. In order to enable accurate determination of the pulse transfer spectrum while using a low dose, the collimator arrangement is constructed so that the scattered radiation from the same section of the primary beam is incident on a plurality of detector elements.

Abstract: The invention provides an inspection system for closed containers, such as luggage, which applies radiant energy, such as x-rays, to a container and receives energy which is scattered, such as by Compton scattering, by objects in the container. The received energy is measured and a three-dimensional image of the objects in the container is constructed. The container may be moved relative to a fan-shaped primary x-ray beam, which illuminates a single slice of the container at a time. For example, the container may be moved by a conveyer belt, or, the container may be held stationary while the x-ray tube may comprise a steerable beam. A plurality of collimated x-ray sensors may receive energy which is scattered, at a fixed angle for each sensor, and transmits those measurements to a processor which reconstructs the three-dimensional image and displays that image for an operator.

Abstract: A first diaphragm arrangement is between a polychromatic X-ray radiator and an examination region for passing a primary radiation beam traversing the examination region on the generated surface of a cone. A detector arrangement comprising several detector elements receives radiation passed by the first diaphragm arrangement and a second diaphragm arrangement, which is located between the examination region and the detector arrangement and assigns to each respective detector element the scattered radiation which is scattered in a part of the primary radiation beam at a given scattering angle. The association between the individual sections of the primary radiation beam and the different detector elements is such that the second diaphragm arrangement has a slot-shaped opening and the shape of the slot-shaped opening and of the detector elements is adapted to the shape of a cross-section of the primary radiation beam.

Abstract: An X-ray analyzer capable of reducing the effects of a shift of peak positions in an energy spectrum resulting from a change in temperature and a lapse of time in an X-ray detector to enable a highly accurate analysis.A shift of peak positions of X-rays from known positions are detected and a voltage applied to a proportional counter is controlled on the basis of the detected results. In addition, a gain in an amplifier amplifying an output from the X-ray detector may be controlled on the basis of the detected results.

Abstract: A device for detecting nitrogenous, phosphoric, chloric and/or oxygenous substances inside an object, particularly of explosives or addictive substances in pieces of luggage. A nuclear activating device stimulates the emission of positron radiation from nitrogen, phosphorous, chlorine and/or oxygen, and an activity measuring device records positron-electron annihilation radiation.

Abstract: The amount by weight of TiO2 per gallon of paint in a paint sample is determined by X-ray fluorescence spectroscopy. The sample is prepared by weighing a portion of the sample while wet and then drying the sample. The dried sample is then calcined to produce an ash residue, which is weighed. The ash residue is then ground and heated to drive off any remaining moisture before being fused with a flux material into a glass bead. The amount of TiO2 in the fused glass bead is determined by an X-ray fluorescence instrument which has been previously calibrated with similar fused glass beads having known amounts of TiO2. The quantitative result of the X-ray fluorescence determination is then extrapolated back to determine the pounds of TiO2 per gallon of paint.

Abstract: A technique for detecting explosives using resonance fluorescence of bremsstrahlung radiation is disclosed. The method is particularly attractive as a way to detect bombs at airports and other transportation terminals. According to the invention, bremsstrahlung radiation is made incident on a target (e.g., a piece of luggage) to resonantly excite the atoms of the target. In one embodiment, the energies of the photons scattered directly from the target are detected and measured. These energies are characteristic of the nuclear species excited in the target, and thus the concentrations of these elements in the target can be determined. A high concentration of nitrogen and oxygen with a low concentration of carbon indicates practically without fail an explosive material. In another embodiment, the energies of photons resonantly scattered from reference scatterers composed substantially of nuclear species of interest and located downstream from the target are detected and measured.

Abstract: A method and apparatus for measuring simultaneously the thickness and the composition of a coating on a metal substrate. A first beam of radiation that produces a primary beam of photons is directed substantially perpendicularly to the surface of the coating. A first detector is positioned substantially perpendicularly to the surface of the coating to receive a first fluoresced beam. The photons having a first energy level representing a higher concentration element of the coating are selected. A first electrical signal is provided that is a function of the intensity of the photons having the first energy level. A second beam of radiation producing a second primary beam of photons is directed at an acute angle to the surface of the coating. A second detector is positioned substantially perpendicularly to the surface of the coating to receive a second fluoresced beam. The photons having a second energy level representing a lower concentration element of the coating are selected.

Abstract: A light-weight hand-held contraband detection system (10) includes two different sources (74) of low energy gamma rays. Each gamma ray source selectively emits gamma rays at a different energy level, which gamma rays are directed to a specific volume (30) of an object, e.g. a vehicle, being searched. The hand-held detection system also includes a gamma ray detector (42) coupled to a visual indicator (14), which indicator visually indicates the relative number of back-scattered gamma rays reflected back from the object being searched. Back scattering of the emitted gamma rays occurs in differing degrees depending upon the density and contents of the particular volume of the object receiving the gamma rays. Certain changes in density reflect the possibility that contraband, such as drugs, may be concealed in the object being searched. In use, the system is gripped in a hand of the user and passed over the surface of the object being searched.

Abstract: The invention relates to an apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: Articles (14) are moved downwardly along a slideway (52) which includes a stop gate (50). The stop gate (50) is moved into the slideway (52) to stop the article (14). Then an instrument (44) is moved toward the slideway (52) and the article (14) to place the instrument (44) contiguous the article (14). The instrument irradiates the article (14). This radiation excites the elements in the article (14), causing them to give off their own characteristic x-rays. The energy of the characteristic x-rays identifies the elements and possibly also the element's concentration. Following the analysis the instrument (44) is raised and the stop gate (50) is lowered, allowing the article (14) to move forward along the slideway (52). Drill bits (14) are analyzed in this manner to differentiate between drill bits (14) of different hardness but identical geometric characteristics.

Abstract: An improved system for radiographically inspecting a relatively stationary object and a related method are disclosed. A source transmits radiation toward a selected location at which the object is positioned. Radiation interactive with the object is thereafter transmitted in one embodiment to a detection area having electronic detectors and another embodiment through an atomic element filter to the detection area. En route to the detectors area or the filter and detection area, radiation is first blocked by a scanning point selection means which sequentially selects only a pencil beam portion of the radiation to be transmitted to the detection area at any given time. The pencil beams sequentially selected sweep the entire detection area over a short time, enabling use of signals generated by the electronic detectors in obtaining an image of the object or for obtaining the identity and location of atomic elements constituting the object.

Abstract: A method is disclosed for obtaining the density distributions of three-dimensional elements that compose objects or groups of objects, by examining the objects with beams of x-rays or gamma radiation that are transmitted through the object in a plurality of approximately parallel paths and measuring the intensity of the radiation, scattered approximately perpendicular to the parallel paths, in arrays of detectors around the object. The energy of the x-rays or gamma rays is such that dominant interaction in the object is Compton scattering. The density of each element is determined from the totality of measurements by standard mathematical tomographic or relaxation techniques of data manipulation.