Abstract: A system for producing beams of high energy photons and neutrons and a method to use such beams to actively interrogate and detect concealed nuclear materials, radiological materials, and chemical explosives.

Abstract: The system and method provide security and cargo handling personnel a versatile tool to rapidly check cargo for hidden radiological materials, explosives, drugs, and chemical weapons material. Gamma ray emission is stimulated by a pulsed neutron source. The gamma ray signature is used to classify the material. Passive gamma ray analysis can be used to detect and identify radiological material. The method of determining the contents of a target includes irradiating a target; detecting at least one spectrum emitted from the target; performing a primary analysis to extract a first set of indicators; and performing a secondary analysis to decide the contents of the target. The primary analysis utilizes either a least squares analysis or principal component analysis. The secondary analysis utilizes a generalized likelihood ratio test or support vector machines.

Abstract: In accordance with an embodiment, a method of examining contents of an object is disclosed comprising conducting a first examination of an object, checking for the presence of delayed neutrons if the first examination indicates that suspect material is present, and determining whether the object contains nuclear material based, at least in part, on the check. The first examination may comprise a manual examination and scanning of the object to form an image, for example. The first examination may also comprise scanning of the object at two different radiation energies, calculating a function of the energy detected at the two radiation energies, and determining whether the object at least potentially contains suspect material based, at least in part, on the comparison. Systems are also disclosed.

Abstract: This invention is related to equipment and techniques for fast neutron activation analysis of explosives and /or other warfare agent. The techniques are based on 14 MeV fast neutrons from D-T fusion reaction, the kinematics of the nuclear reaction and fast coincidence between ?-particles of the D-T reaction and ?-quanta from fast neutron induced reactions. A fast neutron generator with effective target cooling and different operation modes provides high neutron yield, long life, and simple maintenance of the equipment and good geometric resolution of the directional neutron beam. High positional resolution of the directionally scanning neutron beam, high time resolution of the coincidence and high neutron yield provide the real time robust screen of explosives with high speed and/or high sensitivity, flexibility for big and small items and overall high probability of detection (PD) and low probability of false alarms (PFA). The remote video scan device also has zooming capability to change solid angle.

Abstract: A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

Abstract: A real-time method and computer system for identifying radioactive materials which collects gamma count rates from a HPGe gamma-radiation detector to produce a high-resolution gamma-ray energy spectrum. A library of nuclear material definitions (“library definitions”) is provided, with each uniquely associated with a nuclide or isotope material and each comprising at least one logic condition associated with a spectral parameter of a gamma-ray energy spectrum. The method determines whether the spectral parameters of said high-resolution gamma-ray energy spectrum satisfy all the logic conditions of any one of the library definitions, and subsequently uniquely identifies the material type as that nuclide or isotope material associated with the satisfied library definition. The method is iteratively repeated to update the spectrum and identification in real time.

Abstract: A substance analyzer utilizing Prompt Gamma Neutron Activation Analysis for identifying characteristics of a substance and method of manufacturing the same are disclosed. The analyzer is small enough to be portable and to allow its use in many applications where current analyzers cannot be utilized. The analyzer uses a neutron radiation source and a gamma-ray detector to activate the sample material and detect the prompt gamma rays emitted by the sample material. A novel housing for such an analyzer and method for making the housing are also described. Novel methods of operating such an analyzer including via a communications network are also disclosed. Also disclosed are data analysis methods that improve the accuracy and sensitivity of the results of such material analysis.

Abstract: A method for identifying at least one threat to the homeland security. Each threat is either hidden inside at least one cargo container before transit, or is placed inside at least one cargo container while in transit. Each threat while interacting with its surrounding generates a unique threat signature. The method comprises the following steps: (A) detecting at least one threat signature; and (B) processing each detected threat signature to determine a likelihood of at least one threat to become a threat to the homeland security.

Abstract: A method and associated apparatus for detecting concealed fissile, fissionable or special nuclear material in an article, such as a shipping container, is provided. The article is irradiated with a source of fast neutrons, and fast neutrons released by the fissile or fissionable material, if present, are detected between source neutron pulses. The method uses a neutron detector that can detect and discriminate fast neutrons in the presence of thermal neutrons and gamma radiation. The detector is able to process high count rates and is resistant to radiation damage, and is preferably a solid state neutron detector comprised of silicon carbide.

Abstract: Apparatus and methods for measuring radiation in a borehole environment using a YAlO3:Ce (YAP) scintillation crystal. Borehole instruments are disclosed which employ a gamma ray detector comprising a YAP scintillator coupled to a light sensing means such as a photomultiplier tube. One instrument embodiment combines a YAP scintillation detector and a source of pulsed neutrons. Borehole environs are irradiated with neutrons, and induced gamma radiation is measured using a YAP scintillation detector. Response of the detector is used to determine characteristics of the borehole environs. Mechanical and physical properties of YAP are utilized to obtain improved measurements. The relatively short light decay constant of YAP minimized pulse pile-up in the detector when measurements require that the detector be operated during a neutron pulse.

Abstract: The device comprises a detector (15) of radiation that could be neutron radiation and a detector (16) of another type of radiation, for example gamma radiation. The process consists in deducing a burn up fraction or irradiation of the nuclear fuel (26) by the measurement of the measured value of a radiation, while assuming that the fuel has a defined composition. One deduces from this the activity of the other radiation that one should obtain, and the accuracy of the assumption of the composition of the fuel if the measured value is close to this deduced value. The device (1), which makes it possible to obtain satisfactory measurements in a water filled storage bay (26), is fitted with means for attaching it to a boom (3) and for positioning it (6, 9) in a given position on a fuel storage cell structure (4). The device is displaced towards each fuel element.

Abstract: The present invention relates to the use of positron annihilation spectroscopy (PAS) as a method for the measurement of material damage in hot gas path components in industrial gas turbines. A method measuring material damage, expended life and remaining life, using PAS, in nickel and cobalt based superalloy turbine components where the damage has been created by engine operational exposure, is provided. The method can also be used to assess damage to metal components in steam turbines, heat exchangers and generators, as well as damage to other metal, ceramic, plastic and composite articles.

Abstract: A magnet for use with a neutron scattering apparatus. The neutron scattering apparatus provides an incident beam of neutrons to a sample under analysis. The magnet has first and second body portions of high conductivity material and has a mid-plane portion there between in which the sample under analysis is positioned. The first and second body portions of the coil are electrically connected to each other via the mid-plane portion of the coil between the body portions of the coil. The conductive mid-plane portion has a split that allows neutron scattering through large angles.

Abstract: A method of producing an isotope comprising directing electrons at a converting material coated with a coating material, the coating material having an atomic number of n, whereby interaction of the electrons with the converting material produces photons, and whereby the photons produced interact with the coating material to produce an isotope having an atomic number of n−1. In preferred embodiments, the converting material is Tungsten, the coating material having an atomic number of n is Radium-226, and the isotope having an atomic number of n−1 is Radium-225.

Abstract: A neutron radiation installation for treatment of different types of cancer tumours, comprising a source of neutrons (11), like a nuclear reactor or an accelerator dependent source of radiation, a conventional filter (14) for reducing the radiation energy to a suitable level for radiation treatment of cancer tumours, having low energetic neutron beams of an energy of between 1 eV and 40 keV, or preferably between 1 keV and 20 keV, and a radiation tube (22) out of which radiation beams are emitted towards a patient (10) having a cancer tumour (23), whereby an optimum radiation is obtained at a distance of between 50 and 100 cm from the output surface of the conventional filter (14), and in which the installation comprises an additional radiation filter (21) mounted between the conventional filter (14) and the output of the radiation tube, which additional filter is of a material which filters off neutrons in the epithermic spectrum from low energetic neutron beams up to an energy of about 1 keV, in particular

Abstract: Method for analyzing a primary neutron beam of a neutron source, a neutron source having a beam monitor, and a beam monitor. Fission chambers which are arranged in the primary neutron beam are known as beam monitors. Fission processes initiated by the neutrons produce in the fission chambers free charge carriers which, given an applied electric voltage, effect an ionization current pulse by means of which the neutron is counted. Produced as by-product during fission are undesired fast neutrons and high-energy gamma radiation. In addition, the flux of slow neutrons can be substantially attenuated by the gas filling of the fission chambers. These disadvantages can be avoided in the case of the novel method, the novel neutron source and the novel beam monitor. Neutrons are scattered incoherently out of the primary neutron beam (1) by means of a scattering foil (4). A portion of the scattered neutrons (5) strike a detector device (6) which is arranged outside the primary neutron beam (1).

Abstract: A system provides non-invasive stoichiometric detection and imaging of chemical elements and compounds in a material to be analyzed. The system includes a particle generator which generates first and second particles at a target position a first distance from the material. The system further comprises a photon detector capable of detecting photons resulting from irradiation of the material by the first particles and generating a plurality of first electrical signals. The system further comprises a particle detector array for detecting the second partices at a second distance, larger than the first distance, from the target position and generating a plurality of second electrical signals. The system further comprises an analyzer comprising a processor that produces a plurality of filtered electrical signals.

Abstract: A system and method for rapidly analyzing elemental abundances in rock or soil samples (14) under field conditions. The system uses a portable neutron source (12) to allow neutron activation analysis of elements having identifiable radioactive decay characteristics. A radiation detector (18) detects radiation released by the sample (14) and provides radiation testing results to an amplifier (26) for computing the concentration of trace elements in the sample with a high degree of accuracy.

Abstract: A method of maintaining measurement accuracy of specific constituents in prompt gamma neutron activation analyzers in a flow of bulk material having a known range of flow rates comprising of the steps of providing a plurality of samples of the bulk material in the form of standard geometric units, each said unit having the same concentration of the specific constituent to be measured and said units in a form that can be arranged to pass through the analyzer in the same manner as the bulk material; for insertion into the analyzer in geometries and quantities referred to as loading profiles that range from the smallest to the largest flow rates to be expected with the specific bulk material and the specific analyzer, successively inserting each of the loading profiles into the analyzer and measuring long enough to yield a measurement uncertainty that is small compared to the observed differences in analysis results from one loading to another, and recording these results and computing the differences of the mea

Abstract: The present invention relates to a method and portable apparatus which is used to detect substances, such as explosives and drugs, by neutron irradiation. The apparatus has a portable neutron generating probe and corresponding controllers and data collection computers. The probe emits neutrons in order to interrogate an object. The probe also contains gamma ray detectors for the collection of gamma rays from fast neutron, thermal neutron and neutron activation reactions. Data collected from these detectors is sent to the computer for data de-convolution then object identification in order to determine whether the object being interrogated contains explosives or illicit contraband.

Abstract: A system and method for rapidly analyzing elemental abundances in rock or soil samples (14) under field conditions. The system uses a portable neutron source (12) to allow neutron activation analysis of elements having identifiable radioactive decay characteristics. A radiation detector (18) detects radiation released by the sample (14) and provides radiation testing results to an amplifier (26) for computing the concentration of trace elements in the sample with a high degree of accuracy.

Abstract: A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

Abstract: As the material with which a measurement system in a detection apparatus is built, the neutron absorber-loaded polyethylene which considerably slows down and absorbs fast neutrons is replaced by iron or an alloy thereof which have no moderating action but have great ability to reflect fast neutrons. With this design, the neutrons admitted into the solid waste under analysis are not only the fast neutrons that go direct into the solid waste from the neutron generating tubes but also the high-energy neutrons reflected from the measurement system. The probability of incidence of nuclear fissions is sufficiently increased to enhance the sensitivity of measurement.

Abstract: A neutron detection system for detection of contaminants contained within a bulk material during recycling includes at least one neutron generator for neutron bombardment of the bulk material, and at least one gamma ray detector for detection of gamma rays emitted by contaminants within the bulk material. A structure for analyzing gamma ray data is communicably connected to the gamma ray detector, the structure for analyzing gamma ray data adapted. The identity and concentration of contaminants in a bulk material can also be determined. By scanning the neutron beam, discrete locations within the bulk material having contaminants can be identified.

Abstract: A method is provided for the quantitative determination of fissile material content in small size particles present in samples. The samples are sandwiched in organic sheets and then submitted to a defined thermal neutron fluence whereupon fission products of the fissile material in the sample create in the sheets fission tracks which are rendered visible by etching the sheets. Then the size of selected particles having created such tracks is. determined by means of a microscope and thereafter these visible tracks of the selected particles are compared to pre-established standard tracks obtained by the same process from particles of different stepped known size and enrichment ratio.

Abstract: An on-line material analyzer which utilizes pulsed neutron generation in order to determine the composition of material flowing through the apparatus. The on-line elemental material analyzer is based on a pulsed neutron generator. The elements in the material interact with the fast and thermal neutrons produced from the pulsed generator. Spectra of gamma-rays produced from fast neutrons interacting with elements of the material are analyzed and stored separately from spectra produced from thermal neutron reactions. Measurements of neutron activation takes place separately from the above reactions and at a distance from the neutron generator. A primary passageway allows the material to flow through at a constant rate of speed and operators to provide data corresponding to fast and thermal neutron reactions. A secondary passageway meters the material to allow for neutron activation analysis. The apparatus also has the capability to determine the density of the flowed material.

Abstract: An on-line material analyzer which utilizes pulsed neutron generation in order to determine the composition of material flowing through the apparatus. The on-line elemental material analyzer is based on a pulsed neutron generator. The elements in the material interact with the fast and thermal neutrons produced from the pulsed generator. Spectra of gamma-rays produced from fast neutrons interacting with elements of the material are analyzed and stored separately from spectra produced from thermal neutron reactions. Measurements of neutron activation takes place separately from the above reactions and at a distance from the neutron generator. A primary passageway allows the material to flow through at a constant rate of speed and operators to provide data corresponding to fast and thermal neutron reactions. A secondary passageway meters the material to allow for neutron activation analysis. The apparatus also has the capability to determine the density of the flowed material.

Abstract: The invention relates to an analyzer for the identification of explosives and/or chemical warfare agents, with a neutron source which causes the emission of characteristic &ggr; quanta, whereby the analysis system consists of a mobile frame to which a neutron source and a detector as well as a holder for the object are attached, with a neutron generator which contains deuterium as the target, generates neutron pulses by periodically repeated, pulsed bombardment of the target and is controlled so that short neutron pulses are emitted and repeated periodically, whereby the detector is controlled so that in cycles it detects &ggr; quanta promptly emitted from the object due to inelastic neutron scattering and neutron capture, within at least two consecutive temporal measurement windows, whereby the first measurement window at least partially overlaps temporally the neutron pulse and the subsequent second measurement window does not, whereby in the first measurement window &ggr; quanta are essentially detected du

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 detector for fissile materials which provides for integrity monitoring of fissile materials and can be used for nondestructive assay to confirm the presence of a stable content of fissile material in items. The detector has a sample cavity large enough to enable assay of large items of arbitrary configuration, utilizes neutron sources fabricated in spatially extended shapes mounted on the endcaps of the sample cavity, incorporates a thermal neutron filter insert with reflector properties, and the electronics module includes a neutron multiplicity coincidence counter.

Abstract: A technique for determining percent body fat using neutron inelastic scattering is disclosed. It relies on a correlation between a carbon-oxygen ratio in the body and the percent body fat with corrections made for a level of patient hydration in the lean tissue. The animal body is irradiated with neutrons having sufficient energy to inelastically scatter off carbon and oxygen. The resulting gamma rays are detected and counted, and the level of hydration is measured. The ratio of the detected gamma rays and hydration are then related to a proportion of fat in the animal body. This technique provides accuracy approaching that achieved with hydrodensitometry with only small radiation doses between 5 and 20 millirem, but without any requirements for immersion.

Abstract: A technique for determining percent body fat using neutron inelastic scattering is disclosed. It relies on a correlation between a carbon-oxygen ratio in the body and the percent body fat with corrections made for a level of patient hydration in the lean tissue. The animal body is irradiated with neutrons having sufficient energy to inelastically scatter off carbon and oxygen. The resulting gamma rays are detected and counted, and the level of hydration is measured. The ratio of the detected gamma rays and hydration are then related to a proportion of fat in the animal body. This technique provides accuracy approaching that achieved with hydrodensitometry with only small radiation doses between 5 and 20 millirem, but without any requirements for immersion.

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 method is provided for performing nondestructive examination of a metal specimen using neutron activated positron annihilation wherein the positron emitter source is formed within the metal specimen. The method permits in situ nondestructive examination and has the advantage of being capable of performing bulk analysis to determine embrittlement, fatigue and dislocation within a metal specimen.

Abstract: A modular assembly for a bulk material includes container modules defining at least one radiation source cavity, at least one radiation detector channel and a passageway disposed for enabling passage of the conveyor belt through an activation region; and radiation shielding material disposed within the container means. A lower primary module contains a first portion of the radiation shielding material and defines either the radiation source cavity or the radiation detector channel. An upper primary module contains a second portion of radiation shielding material and defines the other of either the radiation source cavity or the radiation detector channel. A set of replaceable side modules contain additional portions of the radiation shielding material.

Abstract: A multisensor vehicle-mounted mine detector having one or more sensors leading the vehicle for detecting objects in the ground while moving. A navigational system tracks the coordinates of the detected objects, performs data fusion, declares whether the object is a target worthy of interest and if so, stops the vehicle with a trailing thermal neutron activator sensor (TNA) over the coordinates of the object and interrogating the object with slow neutrons to confirm whether it contains sufficient nitrogen to indeed be a mine. The TNA confirmation is kept brief due to the use of a strong source coupled with means for analysing the resultant pulses and rejecting piled-up pulses. The difference between an integration of the entire pulse and a portion of the pulse is compared against a predetermined difference for a normal pulse wherein variations therebetween are indicative of a piled-up pulse which is then rejected.

Abstract: The present invention relates to a method and portable apparatus which is used to detect substances, such as explosives and drugs, by neutron irradiation. The apparatus has a portable neutron generating probe and corresponding controllers and data collection computers. The probe emits neutrons in order to interrogate an object. The probe also contains gamma ray detectors for the collection of gamma rays from fast neutron, thermal neutron and neutron activation reactions. Data collected from these detectors is sent to the computer for data de-convolution then object identification in order to determine whether the object being interrogated contains explosives or illicit contraband.

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 source for boron neutron capture therapy (BNCT) comprises a body of photoneutron emitter that includes heavy water and is closely surrounded in heat-imparting relationship by target material; one or more electron linear accelerators for supplying electron radiation having energy of substantially 2 to 10 MeV and for impinging such radiation on the target material, whereby photoneutrons are produced and heat is absorbed from the target material by the body of photoneutron emitter. The heavy water is circulated through a cooling arrangement to remove heat. A tank, desirably cylindrical or spherical, contains the heavy water, and a desired number of the electron accelerators circumferentially surround the tank and the target material as preferably made up of thin plates of metallic tungsten.

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: In a bulk material analyzer in which bulk material is received in an activation region between a pair of neutron sources laterally disposed on one side of the activation region for emitting neutrons for bombarding the bulk material within the activation region to cause gamma-rays to be emitted from the bombarded bulk material and a pair of gamma-ray detectors laterally disposed on an opposite side of the activation region for detecting gamma-rays emitted from the bulk material, and in which a neutron moderator is disposed between the neutron sources and the activation region for reducing the velocity of the emitted neutrons such that the neutrons entering the activation region include thermal neutrons and faster neutrons, the uniformity of sensitivity of the bulk material analyzer to materials at different positions in a sample of the bulk material being analyzed is enhanced by controlling the proportions of thermal neutron at different positions within the sample being analyzed.

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: Prompt Gamma Neuteon Activation Analysis (PGNAA) is employed to determined in situ the content of nickel, copper, or other embrittlement-enhancing elements within the weld metal joints of nuclear reactor pressure vessels.

Abstract: In a bulk material analyzer in which bulk material is received in an activation region between a pair of neutron sources laterally disposed on one side of the activation region for emitting neutrons for bombarding the bulk material within the activation region to cause gamma-rays to be emitted from the bombarded bulk material and a pair of gamma-ray detectors laterally disposed on another side of the activation region for detecting gamma-rays emitted from the bulk material, a primary neutron moderator is disposed about the neutron sources for reducing the velocity of the emitted neutrons; and a secondary neutron moderator is disposed about the primary neutron moderator for further reducing the velocity of the neutrons and is further disposed adjacent the lateral edges of the activation region for channeling and reflecting the neutrons into the activation region.

Abstract: A method and apparatus, suitable for in-line use, provides for determination of pre-reduction degree (PRD) of an iron oxide material, by application of a neutron inelastic scattering technique. The material is exposed to bombardment with neutrons from a source yielding the neutrons at an energy level sufficient to produce prominent gamma-rays from neutron inelastic scattering. The gamma-rays are captured and analysed to obtain an output representative of the relative weight percentages of the elements iron and oxygen, based on at least one characteristic energy level for gamma-rays emitted by those elements. The PRD for the material is determined on the basis of those weight percentages.

Abstract: Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the .sup.16 O(n,p).sup.16 N reaction using .sup.14 -MeV neutrons produced at the neutron source via the .sup.3 H(d,n).sup.4 He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second .sup.16 N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.

Abstract: A method of generating a neutron-radiographic image of a sample by passing a generated neutron beam through a multiple-channel, multiple-total-external reflection neutron bender/filter manipulator which includes at least one multiple-channel element, directing an output beam from the neutron bender/filter manipulator onto the sample; passing a neutron beam exiting the sample though a multiple-channel, multiple-total-external reflection neutron scatter-rejection manipulator which includes at least one multiple-channel element, the multiple-channel element being comprised of a material containing a nuclear isotope which is highly absorptive to neutrons with energies less than approximately 10,000 eV; and detecting a beam which exits the scatter-rejection manipulator.

Abstract: A system for determining depth profiles of concentrations of hazardous elements in soils comprises a neutron source for generating neutrons of a first energy level and irradiating a volume of soil with the neutrons. Nuclear reactions are effected within the soil and gamma radiation is emitted from the soil. The system also includes an array of gamma detectors for detecting gamma radiation emitted from the soil; source electronics for controlling the width of regularly repeated pulses of neutrons generated by the neutron source; detector electronics associated with the gamma detectors for amplifying and digitalizing signals generated by the gamma detectors and storing data representing the digitalized signals; spectral analysis software for analyzing the data and determining the concentrations of selected target elements in the soil; and an acquisition interface module (AIM).

Abstract: A method for determining the corrosion behavior of a material with respect to a medium in contact with the material by: implanting a substantially chemically inert gas in a matrix so that corrosion experienced by the material causes the inert gas to enter the medium; placing the medium in contact with the material; and measuring the amount of inert gas which enters the medium.A test sample of a material whose resistance to corrosion by a medium is to be tested, composed of: a body of the material, which body has a surface to be contacted by the medium; and a substantially chemically inert gas implanted into the body to a depth below the surface.

Abstract: Fast neutrons from a moving source are thermalized by travel through water to a soil embedded body of nitrogen-rich material causing emission of gamma rays therefrom. Emitted gamma rays are detected at a location adjacent the neutron source for measurement of radiation energy from which location of nitrogen-rich materials in the soil is mapped, based on a predetermined signature energy level of the measured radiation.