Abstract: Two gamma-rays emitted simultaneously from each of the radionuclides in a radioactivated sample are simultaneously measured with a multiple gamma-ray detector assembly to construct a two-dimensional matrix rather than a one-dimensional spectrum, and the individual nuclides are measured in a completely separate form without performing any artificial operation such as chemical separation.

Abstract: In accordance with the present invention, there is provided a proton beam target for generating gamma rays which are generated therefrom in response to an impinging proton beam. The proton beam target is provided with a 13C gamma reaction layer for generating the gamma rays therefrom. The proton beam target is further provided with a stopping layer for mitigating transmission of the proton beam therethrough. The stopping layer is formed of a refractory metal which is hydrogen soluble for dissolving implanted hydrogen molecules therewithin as a result of the impingement of the proton beam and which is chemically reactive with the 13C gamma reaction layer for chemically bonding therewith.

Abstract: This invention provides coded aperture imaging apparatus and methods for the detection and imaging of radiation which results from nuclear interrogation of a target object. The apparatus includes: 1) a radiation detector for detecting at least a portion of the radiation emitted by the object in response to nuclear excitation and for producing detection signals responsive to the radiation; 2) a coded aperture disposed between the detector and the object such that emitted radiation is detected by the detector after passage through the coded aperture; and 3) a data processor for characterizing the object based upon the detection signals from the detector and upon the configuration of the coded aperture.

Abstract: A technique for assaying samples entails irradiating a sample with a beam of gamma rays of sufficient energy to excite the nuclei of the assay elements into their isomeric states, ceasing the irradiation, detecting the gamma rays resulting from the decay of the isomeric states to the ground state, and analyzing the detected gamma rays to determine the content of assay elements in the sample. In a preferred embodiment, the apparatus is configured such that the irradiated sample is rapidly moved to a shielded environment in which the gamma rays from the isomeric transitions are detected. The system is ideally suited for analyzing large samples of ore for gold, silver, barium and other assay elements, but can be embodied to detect any assay elements susceptible to photon activation analysis in any sample geometry.

Abstract: A method and apparatus is disclosed for inspecting a wall to evaluate the remaining thickness of the wall as well as the extent to which the wall has been infiltrated by another material. The disclosure discusses directing photons of radiation and/or neutrons into the wall and measuring and analyzing the radiation emitted from the wall as a result of Compton scattering, pair production, photoelectric absorption and/or neutron absorption. The invention is particularly well suited for inspecting a carbon hearth-wall liner of an iron-smelting blast furnace.

Abstract: A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis.The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Abstract: The present invention is directed to an analytic method for detecting trace elements in fluid solution. A cation exchange resin is packed with a radiolabelled exchange material having certain characteristics and replaces the trace element ions in the fluid which becomes labelled. The label is subsequently detected using sensitive and well known radiation detection methods.

Abstract: A hydrogen ion accelerator produces a beam current that is at least ten times greater than the current supplied by an electrostatic generator by recycling the unreacted portion of the beam. In one application, a 1.76 MeV proton beam is used to generate 9.172 MeV gamma rays for detecting explosives (nitrogen) via either the .sup.13 C reaction. The cross-section of the 1.76 MeV proton beam with the carbon 13 target is such that over 95 percent of the beam passes through the target unreacted. In a preferred embodiment, a proton source (52) disposed within a high voltage electrode (32) forms a proton beam that is accelerated along the length of an acceleration tube (46), is bent 180.degree. by bending magnets (70, 72), passes through a target foil (76), is decelerated along the length of a deceleration tube (82), and is returned to the high voltage electrode (32) where the energy contained in the beam is recaptured.

Abstract: A bulk material analyzer of the type in which the bulk material is transported through the material analyzer assembly on a conveyor belt between at least one radiation source and at least one radiation detector, includes a plurality of lower and upper modules that contain radiation shielding material and are so shaped as to define a passageway for the conveyor belt between the upper modules and the lower modules when the upper modules are placed on the lower modules. A primary centrally located lower module also includes the radiation sources and a primary centrally located upper module also includes the radiation detectors. Some of the outwardly located modules contain less radiation shielding material. The radiation shielding material includes a plurality of personally portable blocks. The conveyor belt is supported by compressed air passed through central upper wails in the outwardly located lower modules.

Abstract: A detector structure adjacent an opening in a cavity structure for detecting explosives in objects within such opening including a plurality of thin nonchlorinated hydrogenous wall members forming a passageway to define such opening. A source of high energy neutrons located adjacent the passageway to direct neutrons into the passageway. A premoderator formed by nonchlorinated hydrocarbon material surrounding the source of high energy neutrons to reduce the energy in at least a portion of the neutrons. A first moderator formed by heavy water surrounding the source of neutrons and the premoderator to reduce the energy in at least a further portion of the neutrons. A second moderator formed by carbonaceous material at least partially surrounding the plurality of thin hydrogenous wall members and the first moderator to reduce the energy in at least an additional portion of the neutrons and reflect back the additional portion of neutrons into the opening.

Abstract: A method in which a surface layer material whose amount of reduction is to be measured is activated to find a distribution ratio of two or more kinds of radioactive nuclides that are produced in the space in the surface layer of the material, and the distribution ratio is used as an index for the amount of reduction of surface layer material. The amount of reduction in the surface layer material is measured in situ, nondestructively, easily and irrespectively of obstacles and the distance that exist between the detector and the material that is to be measured.

Abstract: Generating nuclear resonance-produced gamma rays of .sup.14 N, .sup.16 O (and C1) for scanning objects such as luggage that may contain explosives of nitrogen-oxygen (-chorine) constituents, and detecting such by Resonance Absorption Analysis (RAA) techniques, and with increased yield of gamma ray generation with novel resonance targets, thin layer and gaseous, particularly of the resonance gamma rays of .sup.14 N.

Abstract: A detector structure adjacent an opening in a cavity structure for detecting explosives in objects within such opening including a plurality of thin nonchlorinated hydrogenous wall members forming a passageway to define such opening. A source of high energy neutrons located adjacent the passageway to direct neutrons into the passageway. A premoderator formed by nonchlorinated hydrocarbon material surrounding the source of high energy neutrons to reduce the energy in at least a portion of the neutrons. A first moderator formed by heavy water surrounding the source of neutrons and the premoderator to reduce the energy in at least a further portion of the neutrons. A second moderator formed by carbonaceous material at least partially surrounding the plurality of thin hydrogenous wall members and the first moderator to reduce the energy in at least an additional portion of the neutrons and reflect back the additional portion of neutrons into the opening.

Abstract: The invention makes it possible to measure the degree of radioactive radiation emitted by large pieces. It includes two large gamma ray detectors (12A, 12B) placed opposite each other and whose spacing is adjustable. They are completed by a photoelectron multiplier (14A, 14B). The piece (2) to be measured is suspended so as to be brought between the two detectors (12A, 12B). The positioning of these detectors is obtained with the aid of a computer and a system (22) for recognizing the shape of the piece (2) functioning with the aid of optical clip-on lenses. The fact that the two detectors are position-adjustable makes it possible to take account of the shape of the piece to be measured. An application is the recovery of materials originating from nuclear installations with the view to re-using the materials.

Abstract: Apparatus and method for decontaminating radioactive materials by stimulating the atomic system of radioactive materials. The stimulus is kept applied to the radioactive materials for a predetermined time. In this way, the rate of decay of the radioactivity of the materials is greatly accelerated and the materials are thereby decontaminated at a rate much faster than normal. The stimulus can be applied to the radioactive materials placing them within the sphere or terminal of a Van de Graaff generator and allowing them to be subjected to the electrical potential of the generator, such as in the range of 50 kilovolts to 500 kilovolts, for at least a period of 30 minutes or more.

Abstract: Paper notes used as a monetary currency are deuterated. The level of deuteration while not complete, is high. For U.S. currency the level of deuteration is at least 0.1 mg of deuterium for each one dollar in value of the currency note, and preferably at least 0.3 mg. Use of X-ray or gamma ray interrogation with a beam energy above 2 MeV produces a nuclear reaction releasing a neutron from the deuterium nucleus. If the currency is in large concentrations, e.g. $100,000 or more, the neutrons emitted by this reaction are reliably detectable. The deuteration occurs in the cellulose fibers forming the currency. To resist an exchange of hydrogen atoms for deterium atoms, the deuterium atoms can be used in the formation of synthetic cellulose where the deuterium is more deeply buried within the cellulose molecule than in naturally occurring cellulose. The deuterated synthetic fibers are blended with natural, non-deuterated fibers to form the paper.

Abstract: A material analyzer includes a container; a radiation source disposed within the container; a detector disposed within the container for detecting radiation that is secondarily emitted by a material sample within an activation region located between the radiation source and the detector when the material sample is bombarded by radiation from the radiation source and for producing signals in response to said secondarily emitted radiation; a computer for processing the signals to determine the content of the material sample; and a carousel for transporting a material sample from outside the container to within the activation region. The carousel is disposed about an axis of rotation located between the activation region and a receiving region located outside the container, and has a pair of sample containment chambers that are alternately moved between the receiving region and the activation region when the carousel is rotated about said axis.

Abstract: Accelerated decay of radioactive materials is used for power production. In the method of this invention an alpha-emitting radioactive material is placed in a region. The region is selected so that when a negative potential is applied to the region, enhanced alpha decay of the radioactive material results. The energy of the alpha decay particles is captured and converted to thermal energy.

Abstract: A method and apparatus for detecting concentrations of nitrogen between 20% and 30% by weight such as is common in explosives is disclosed. A microtron having an output electron beam at a level below 45 MeV is targeted onto a typically tungsten target to provide gamma radiation levels. Deflection magnets adjacent to the target deflect the electron beam of the microtron to cause it to scan. Articles placed on a container containing suspect nitrogen are systematically scanned and output gamma radiation of 511 keV detected from nitrogen. Nitrogen concentrations and consequently expected concealed explosives are easily mapped in two or three dimensions, quantitatively.

Abstract: A method and apparatus for measuring uranium isotope enrichment in a sample uranium solution. In the invention, the concentration of uranium in the uranium solution is determined by K-edge densitometry. The quantity of uranium-235 in the uranium solution is then measured by detecting the gamma rays emitted from the uranium-235 by using a high-purity germanium detector. A value of the uranium isotope enrichment is obtained from the ratio of the quantity of uranium-235 in the uranium solution to the uranium concentration. The invention is designed to provide the improved construction of a radiation source suitable for the K-edge densitometry and to provide the accurate measurements by correcting any error in the measured quantity of uranium-235 in the uranium solution due to the self-absorption of the gamma rays emitted from the uranium-235.

Abstract: A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

Abstract: Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for .sup.239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

Abstract: A method and apparatus for analyzing combined secondary and primary materials by directing primary radiation onto said material whereby secondary radiation is generated. A detector senses the secondary radiation as a transport carries the materials into the vicinity of primary radiation and produces signals to be resolved into secondary and primary material source components, establishing a secondary to primary material ratio and indicating the composition of the material.

Abstract: A system and method of rapidly obtaining quantitative information as to the elemental constituents of coal, particularly the oxygen and sulfer content thereof. The system makes use of the photonuclear interaction to produce the desired radioactivity in the coal constituents. The above mentioned interaction is induced by high energy x-rays from a suitable electron accelerator. The induced radioactivity manifests itself by the emission of characteristic gamma rays among other things. These gamma rays are detected by conventional energy sensitive gamma-ray detectors such as germanium or sodium iodide crystals. The resultant signals are sorted and analyzed to provide the desired information.

Abstract: Measurement of the velocity distribution of confined energetic alpha particles resulting from deuterium-tritium fusion reactions in a magnetically contained plasma is provided. The fusion plasma is seeded with energetic boron neutrals for producing, by means of the reaction .sup.10 B (.alpha.,n) .sup.13 N reaction, radioactive nitrogen nuclei which are then collected by a probe. The radioactivity of the probe is then measured by conventional techniques in determining the energy distribution of the alpha particles in the plasma. In a preferred embodiment, diborane gas (B.sub.2 H.sub.6) is the source of the boron neutrals to produce .sup.13 N which decays almost exclusively by positron emission with a convenient half-life of 10 minutes.

Abstract: A bulk material analyzer of the type in which the bulk material is transported through the material analyzer assembly on a conveyor belt between at least one radiation source and at least one radiation detector, includes a plurality of lower and upper modules that contain radiation shielding material and are so shaped as to define a passageway for the conveyor belt between the upper modules and the lower modules when the upper modules are placed on the lower modules. A primary centrally located lower module also includes the radiation sources and a primary centrally located upper module also includes the radiation detectors. Some of the outwardly located modules contain less radiation shielding material. The radiation shielding material includes a plurality of personally portable blocks. The conveyor belt is supported by compressed air passed through central upper wails in the outwardly located lower modules.