Abstract: A neutron spectrometer is provided by a series of substrates covered by a solid-state detector stacked on an absorbing layer. As many as 12 substrates that convert neutrons to protons are covered by a layer of absorbing material, acting as a proton absorber, with the detector placed within the layer to count protons passing through the absorbing layer. By using 12 detectors the range of neutron energies are covered. The preferred dodecahedron embodiment of the neutron spectrometer comprises a solid, polyethylene dodecahedron assembly with 12 surface facets covered by a solid-state detector stacked on an absorbing layer. In this arrangement, each of 12 surface pentagon-shaped facets provides a polyethylene substrate to convert neutrons to protons, covered by a layer of absorbing material, acting as a proton absorber, with the detector stacked on the absorbing layer to count protons passing through the absorbing layer.

Abstract: The boron concentration can be measured without intervention into the cooling circuit of a nuclear power station. A mobile emitter and a mobile receiver are provided, with the interposition of at least one coolable region, for placement on a coolant-carrying component of the cooling circuit.

Abstract: A flexible source wire is provided containing a radioactive source that is capable of maneuvering through a tortuous narrow passage to a treatment site within the body. This source wire includes a thin flexible housing tube, housing therein a flexible backbone wire, both the tube and the wire being constructed from a material exhibiting little or no memory retention when bent. A radioactive source is provided in the proximal end of the thin flexible housing tube. This radioactive source is contained in a capsule abutting the proximal end of the backbone wire all within a thin wall encapsulating material. Both ends of the source wire are welded shut to form a tight seal and rounded to allow ease of movement as it travels through the bends and turns in the body. The housing tube is coated before the loading of the radioactive material with a non-oxidizing agent such as gold.

Abstract: A flexible source wire is provided containing a radioactive source that is capable of maneuvering through a tortuous narrow passage to a treatment site within the body. This source wire includes a thin flexible housing tube, housing therein a flexible backbone wire, both the tube and the wire being constructed from a material exhibiting little or no memory retention when bent. A radioactive source is provided in the proximal end of the thin flexible housing tube. This radioactive source is contained in a capsule abutting the proximal end of the backbone wire all within a thin wall encapsulating material. Both ends of the source wire are welded shut to form a tight seal and rounded to allow ease of movement as it travels through the bends and turns in the body. The housing tube is coated before the loading of the radioactive material with a non-oxidizing agent such as gold.

Abstract: The present invention includes the use of N-isomers as a source of energy and of neutrons, and the use of K-isomers as a source of energy when associated with a source of neutrons. Although there is strong indirect evidence for the existence of shape isomers in nuclei lighter than actinides, super-deformed (SD) isomeric states have not yet been directly observed. However, rotational bands from such SD states have been observed through &ggr;-ray transitions within high-energy rotational states of this band, as populated by HI reactions. The lifetimes for the shape isomers are likely to be small, but may be increased by effects like the odd-even effects already observed for fission isomers. By contrast, K-isomers have been observed and investigated. If N-isomers are found with the required properties (especially with sufficiently long lifetimes) and produced in sufficient quantities, portable neutron sources more intense than existing neutron sources could be obtained.

Abstract: A new transmutation assembly permits an efficient transmutation of a long-lived radioactive material (long-lived FP nuclides such as technetium-99 or iodine-129) which was produced in the nuclear reactor. Wire-type members of a long-lived radioactive material comprised of metals, alloys or compounds including long-lived FP nuclides are surrounded by a moderator material and installed in cladding tubes to form FP pins. The FP pins, and nothing else, are housed in a wrapper tube to form a transmutation assembly. The wire-type members can be replaced by thin ring-type members. The transmutation assemblies can be selectively and at least partly loaded into a core region, a blanket region or a shield region of a reactor core in a fast reactor. From a viewpoint of reducing the influence on the reactor core characteristics, it is optimal to load the transmutation assemblies into the blanket region.

Abstract: Methods for the production of radionuclides suitable for use in radiopharmaceuticals for diagnostic and therapeutic applications, and specifically, to the production of 186Re, 188Re and other radionuclides such as 195mPt and 198Au using an inorganic Szilard-Chalmers reaction. Thin-film and powdered 185 or 187Reo metal targets, and 185 or 187Re oxide/metal oxide target compositions with rhenium in a lower, relatively reduced oxidation state are prepared. The thin-film rhenium targets are aged for at least about 24 hours and then irradiated with neutrons in the present of an oxidizing medium sufficient to form a product nuclide in the higher oxidized state of perrhenate, ReO4−. Significantly, the rate and/or extent of oxidation of target nuclides which do not react with a neutron is controlled. For example, oxidation of such non-bombarded target nuclides is minimized by irradiating under vacuum, controlling the amount of oxidizing agent present, cooling during irradiation, etc.

Abstract: Palladium-103 radiochemical of high radionuclidic purity can be produced in commercial scale quantities by irradiating enriched Palladium targets comprising a mixture of Pd isotopes with protons or deuterons in the 10-50 MeV energy range. Commercially viable batch sizes with acceptable specific activity of the product Pd-103 are achieved by adjusting the irradiation energy, irradiation time, irradiation current, current density, plated target mass, plated target shape, plated target size, target isotope enrichment levels, and incident angle of the target to the beam. The method for the production of Pd-103 comprises providing a target material enriched with Pd isotopes comprising atomic masses equal to or greater than Pd-103, applying the target material onto a target support; irradiating the target material with protons or deuterons of sufficient incident energy and time to convert at least some of the Pd isotopes within the target material to Pd-103; and purifying Pd from the non-Pd components.

Abstract: A neutron delivery system that provides improved capability for tumor control during medical therapy. The system creates a unique neutron beam that has a bimodal or multi-modal energy spectrum. This unique neutron beam can be used for fast-neutron therapy, boron neutron capture therapy (BNCT), or both. The invention includes both an apparatus and a method for accomplishing the purposes of the invention.

Abstract: Methods for the production of radionuclides suitable for use in radiopharmaceuticals for diagnostic and therapeutic applications, and specifically, to the production of .sup.186 Re, .sup.188 Re and other radionuclides such as .sup.195m Pt and .sup.198 Au using an inorganic Szilard-Chalmers reaction. Thin-film and powdered .sup.185 or 187 Re.degree. metal targets, and .sup.185 or 187 Re oxide/metal oxide target compositions with rhenium in a lower, relatively reduced oxidation state are prepared. The thin-film rhenium targets are aged for at least about 24 hours and then irradiated with neutrons in the present of an oxidizing medium sufficient to form a product nuclide in the higher oxidized state of perrhenate, ReO.sub.4.sup.-. Significantly, the rate and/or extent of oxidation of target nuclides which do not react with a neutron is controlled.

Abstract: A device for generating direct current by neutron activation of a plurality of series-connected beta-emitter (nuclear decay electron) cells, located in the out-of-core region of a light water nuclear reactor. The device can be used as either a current source, or preferably configured as a DC voltage source, capable of powering low-power, radiation-hardened, high-temperature integrated circuitry contained in the reactor vessel. As such, the device acts like a DC battery that is activated by (n, .gamma.) reactions, both thermal and epithermal (by resonance capture). The device is not operable until exposed to a substantial neutron flux, so it has unlimited shelf-life and is not radioactive during manufacture In the preferred embodiment, an isotope of the metallic rare-earth element dysprosium is configured in a "sandwich" geometry to generate sufficient current that a useful steady voltage can be generated by means of a simple voltage regulation circuit.

Abstract: A stand-alone low-voltage direct current power supply, for use as a battery, which is energized by the decay of a radioactive isotope in response to neutron capture. During this decay, either .alpha.- or .beta.-particles are emitted. The emitting radioactive isotope should have adequate half-life and no .gamma.-emission. The preferred .beta.-emitting radioisotope is thallium, which decays directly to the ground state of Pb.sup.204 by 763-keV .beta.-decay with no .gamma.-emission. The resulting .beta.-particles are collected to form a current which can be used for various purposes inside a reactor. The preferred .alpha.-emitting radioisotope is americium.

Abstract: Described is a radiation sensitive imaging film containing a heat fixable radiation sensitive element, e.g., a diacetylene, of the formula: R--C.tbd.C--C.tbd.C--R', where R and R' are, e.g., both --CH.sub.2 --O--CONH--(CH.sub.2).sub.5 CH.sub.3. After exposure to X-radiation during diagnostic or X-ray therapy, the resulting image can be permanently dry fixed by a short heating step and then stored for a long period. Processes for making the film, new binder-convertor systems, and a device incorporating the film are described as well as other imaging, diagnostic and therapeutic methods utilizing the film in high energy radiation applications in the health care field.

Abstract: Methods and apparatus for producing selenium-72, separating it from its daughter isotope arsenic-72, and generating multiple portions of a solution containing arsenic-72 from a reusable parent substance comprised of selenium-72. The invention provides apparatus which can be located at a site where arsenic-72 is used, for purposes such as PET imaging, to produce arsenic-72 as needed, since the half-life of arsenic-72 is very short.

Abstract: A method of fabricating a radioactive core to be integrated within a source wire for use in radiation treatment of tumors within the body of a patient utilizes a thin elongate fiber of substantially pure iridium encapsulated in a straight quartz tube substantially transparent to the flux of a beam of radiation. The iridium fiber is oriented lengthwise along the axis of the tube, so that the fiber is restrained from curling. The tube and the fiber therein are irradiated with a beam directed normal to the axis of the tube while rotating the tube about the axis, to render the fiber radioactive to a predetermined level of activity. The method is adapted to produce a generally cylindrical Ir-192 source having a longitudinal axis of symmetry, a length of about one centimeter, a diameter of about 0.35 millimeter, a weight of about 20 milligrams and a radioactivity level of at least approximately 10 curies.

Abstract: A method of analysis of rock samples taken from the bore of a well being drilled or from the Earth's surface and performed upon the apatite grains contained within the samples. The apatite grains are separated from the surrounding rock, polished to expose internal surfaces, and etched with acid to reveal the presence and characteristics of fission tracks within the apatite to determine the geological characteristics of the apatite. The grains containing the apatite are viewed under an optical microscope or other imaging apparatus and apatite crystals or crystal fragments which contain etched fission tracks are selected for analysis. If selected for analysis, measurements may be taken to determine the size and shape of the etched pits intersecting the apatite grain surface. The measurements are taken using a digitizing apparatus interconnected to a computer and containing a point light source superimposed upon the apatite grains viewed through the microscope.

Abstract: A system for monitoring the radioactivity of a liquid waste stream includes a pair of tanks into which the liquid waste stream is directed during alternating fill cycles. At the conclusion of each fill cycle, the liquid waste is recirculated through the chamber of a radioactivity monitor. A pair of opposed radiation detectors, external to the chamber, generate activity measurements to a controller indicative of the radionuclide concentration levels in the liquid waste. The tanks are then emptied either to the environment or back to a decontamination facility for further processing depending on the indicated radionuclide concentration level. System operation, including periodic servicing of the monitor, is automatically coordinated by the controller to avoid interruption of the liquid waste stream filling the tanks.

Abstract: The invention relates to an apparatus for detecting and measuring water production in oil and gas wells and in injection wells, involving a neutron source for activating oxygen atoms in any water produced or injected in the well, and a plurality of detectors, at least three (3) but preferably four (4), longitudinally spaced within the housing for detecting and counting gamma ray emissions resulting from the oxygen activation.

Abstract: A nuclear detection system and method efficiently detects explosives in checked airline baggage or other parcels with a high probability of detection (PD) and a low probability of false alarms (PFA). The detection system detects the presence of nitrogen and its rough density distribution within the object under investigation by performing a nuclear-based analysis of the object. The detection system includes a source of thermal neutrons; an array of gamma ray detectors; a neutron detector; means for irradiating the object being examined to neutrons from the neutron source, which neutrons interact with the atomic nuclei of one or more specific elements, e.g.

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: Water soluble irradiation targets are disclosed for the production of .sup.186 Re and .sup.188 Re. The irradiation targets are selected for both water solubility and absence of elements which would produce contaminating isotopes for medical therapeutic and diagnostic use. In one embodiment, .sup.186 Re or .sup.188 Re is produced by the direct irradiation of a water soluble irradiation target comprising .sup.185 Re or .sup.187 Re, respectively. Preferred targets for this purpose include aluminum perrhenate, lithium perrhenate and magnesium perrhenate. In another embodiment, a zirconyl tungstate generator comprising .sup.188 W for the production of .sup.186 Re is obtained by irradiating a soluble irradiation target comprising .sup.186 W, dissolving the irradiated target in aqueous solution, reacting the dissolved target with an aqueous solution comprising zirconyl ion to form an insoluble zirconium tungstate precipitate and disposing the precipitate in an elutable container.

Abstract: A gas cooled nuclear reactor may have a stationary pile of spherical operating elements. The reactor may be controlled and shut down by absorber rods displaceable in channels of the side reflector. The neutron sources required for the safe start-up of such pellet pile reactors, which in the case of higher capacity pile reactors are installed in bores of the side reflector, are arranged in the stationary pile, where they are more effective and do not occupy positions in the side reflector. They may be located in one or more graphite elements having the same diameter as the operating elements. These elements may be introduced and removed into and from the core together with the operating elements and remain stationary in operation.

Abstract: A silicon wafer and a method of producing a silicon wafer comprising a phosphor-doping method of doping phosphor into a single silicon crystals by transmuting isotope Si.sup.30 contained in said single silicon crystals made by the CZ method or the MCZ method into p.sup.31 under neutron irradiation to said single silicon crystals.

Abstract: It comprises an enclosure, a neutron emitting source (29) for bombarding said fissile material, means (28, 30) for introducing source (29) into the enclosure and for removing said source from the enclosure, neutron radiation detection means (9), moderator means (2, 4, 6) for thermalizing a fission radiation emitted by said fissile material interposed between the neutron radiation detection means (9) and the fissile material. It also has gamma radiation detection means (6, 14), which comprises a scintillator (6) and at least one photomultiplier (14) associated with said scintillator (6) and the scintillator material also constituting the moderator for thermalizing the fast neutrons directly emitted by the source (29), as well as the neutrons from the spontaneous fissions of the .alpha., n reaction and the neutrons from the fissions induced in the fissile material, the neutron radiation detectors (9) being embedded in the scintillator material (6) constituting the moderator.

Abstract: A process for preparing a tungsten-188/rhenium-188 generator having a tungstate matrix containing W-188 produced by irradiating tungsten-186 in the tungstate compound. High activity, carrier-free rhenium-188 may be obtained by elution. Substrates for further purifying the rhenium-188 eluate are also described.

Abstract: A method for decreasing the amount of hazardous radioactive reactor waste materials by separation from the waste of materials having long-term risk potential and exposing these materials to a thermal neutron flux. The utilization of thermal neutrons enhances the natural decay rates of the hazardous materials while the separation for recycling of the hazardous materials prevents further transmutation of stable and short-lived nuclides.

Abstract: A high energy neutron generator for use in neutron therapy.The generator comprises a source for charged particles (preferably protons) with an energy level equal to at least 15 MeV, a target constituted by at least two lithium deuteride elements, whose thickness is such that under the impact of the charged particles, neutrons with an energy level equal to at least 15 MeV are largely produced in the forward direction, and target cooling means constituted by means for the circulation of a gas which does not chemically react with lithium deuteride. This generator may also comprise a collimator for defining an irradiation field of a patient and a permanent magnet able to deflect the charged particles not absorbed by the target towards a stopping unit positioned in and integrally formed with one wall of the collimator.

Abstract: A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U, .sup.235 U and .sup.239 Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as .sup.240 Pu, .sup.244 Cm and .sup.252 Cf, and the spontaneous alpha particle emitter .sup.241 Am.

Abstract: Films (12) of gold, copper, silicon nitride, or other materials are firmly bonded to insulator substrates (12) such as silica, a ferrite, or Teflon (polytetrafluorethylene) by irradiating the interface with high energy ions. Apparently, track forming processes in the electronic stopping region cause intermixing in a thin surface layer resulting in improved adhesion without excessive doping. Thick layers can be bonded by depositing or doping the interfacial surfaces with fissionable elements or alpha emitters.

Abstract: An irradiation head permitting the positioning of the area to be treated and the checking of this position. This irradiation head, which is disposed downstream of the neutron target, is provided which a turret carried by a supporting plate and which can rotate about an axis zz perpendicular to said plate. The supporting plate has a central opening A of axis ZZ coinciding with the axis of the useful neutron beam and the axis of the collimator. The turret has three openings a.sub.1, a.sub.2, a.sub.3 which can successively face the opening A in accordance with the axis ZZ. Two of the openings a.sub.1, a.sub.2 are respectively associated with a light source S.sub.1 and an X-ray source S.sub.2 emitting beams of mean paths f.sub.1 and f.sub.2 equidistant with respect to axis zz, these beams being respectively designed for the positioning of the area to be treated and the checking of this position.