Abstract: A nondestructive inspecting device (10) includes a neutron emission device (2) that emits a neutron beam to a local irradiation location on a surface (la) of an inspection target (1), a detection device (3) that detects, at each of inspection positions facing the surface (la), scattered neutrons returned from the inspection target (1) as a result of emission of the neutron beam to the irradiation location, and measures the detected number of the scattered neutrons at each of the detection positions, and a ratio calculation unit (5) that calculates, for each of the detection positions, a ratio of the detected number at the detection position to a reference value for the detection position, and outputs the ratios. The reference value is set as the detected number at each of the detection positions in an assumed case of no defects existing in the inspection target (1).

Abstract: Systems, tools and methods for deploying a mesh sensor network. The system comprises one or more aircraft configured to carry one or more drop pods into an environment and the deploying of the drop pods at points of interest. The aircraft and drop pods may comprise arrays of sensors for monitoring the areas that they are operating in. The aircraft and drop pods may include mesh radio communication devices and operate as nodes in the mesh network. The location at which each drop pod is to be deployed may be determined based on the type of sensors carried by the drop pod.

Abstract: Disclosed are a radioisotope activity surveillance system and methods. The system includes a fuel rod assembly having a plurality of nuclear fuel rods and a target assembly having a top nozzle including an orifice plate and at least one target material rod fixedly coupled to the orifice plate. The least one target material rod is slidably disposed within the fuel rod assembly. A sensing assembly defines an opening sized and configured to receive the target assembly therethrough. The sensing assembly includes a self-powered detector assembly to detect radioisotope activity of the target rod material. Also disclosed is a method for measuring a self-powered detector signal to calculate radioisotope activity of a target assembly and a method for analyzing total activity of a desired radioisotope.

Abstract: A method and apparatus for classifying and/or identifying materials by means of their spectral response to gamma radiation. Classification is carried out by irradiating multiple different samples with gamma radiation, detecting a spectral response in the backscatter direction, sorting the spectral response into energy bands and selecting a combination of energy bands to define a relationship that best distinguishes between clusters of spectral responses for different material classes. Two or more of the energy bands may overlap.

Abstract: A neutron capture therapy system may prevent deformation and damage of a material of a beam shaping assembly (20), thereby improving flux and quality of a neutron source. A boron neutron capture therapy system (100) includes a neutron generating device (10) and a beam shaping assembly (20), where the neutron generating device (10) includes an accelerator (11) and a target (T), a charged particle beam (P) generated by acceleration of the accelerator (11) interacts with the target (T) to generate neutrons, the neutrons form a neutron beam (N), the neutron beam (N) defines a main axis (X); the beam shaping assembly (20) includes a moderator (231), a reflector (232), and a radiation shield (233); and the beam shaping assembly (20) further includes a frame (21) accommodating the moderator (231).

Abstract: This disclosure provides systems, methods, and apparatus related to neutron detection and gamma ray detection. In one aspect, a detector comprises a scintillator structure that comprises an organic scintillator and an inorganic scintillator. The organic scintillator is in the form of one or more elements of a specified length. The inorganic scintillator is in the form of one or more elements of the specified length. First ends of the one or more organic scintillator elements and first ends of the one or more inorganic scintillator elements define a first surface. Second ends of the one or more organic scintillator elements and second ends of the one or more inorganic scintillator elements define a second surface.

Abstract: A neutron imaging system includes a neutron generator, a flight tube, a stage, a neutron imaging module, and a neutron shield. The flight tube enables neutrons from the neutron generator to enter the flight tube through an input opening and exit through an output opening. The stage supports a sample object to receive neutrons that pass through the entire length of the flight tube and the output opening. The neutron imaging module has a neutron-sensitive component that receives neutrons that pass through the sample object and generates neutron detection signals. The neutron shield surrounds at least a portion of the flight tube and the neutron imaging module to block at least a portion of stray neutrons that travel toward the neutron-sensitive component of the neutron imaging module, in which the stray neutrons do not enter the flight tube through the input opening of the flight tube.

Abstract: The present disclosure provides systems, apparatuses, and methods for measuring submerged surfaces. Embodiments include a measurement apparatus including a main frame, a source positioned outside a pipe and connected to the main frame, and a detector positioned outside the pipe at a location diametrically opposite the source and connected to the main frame. The source may transmit a first amount of radiation. The detector may receive a second amount of radiation, determine a composition of the pipe based on the first and second amounts of radiation, and send at least one measurement signal. A control canister positioned on the main frame or on a remotely operated vehicle (ROV) attached to the apparatus may receive the at least one measurement signal from the detector and convey the at least one measurement signal to software located topside.

Abstract: A neutron beam diffraction material treatment system utilizes a neutron beam source configured to produce a first neutron beam having a first direction and second neutron beam source configured to produce a second neutron beam having a second direction. The neutron beam diffraction material treatment system can direct the first and second neutron beams to intersect with each other in or on a work-piece and thereby treat the work piece by neutron diffraction. One or more of the neutron beams may be configured to move to change the location of the intersecting point within the work-piece and/or the work-piece may be configured to move. The first and second neutron beams may be configured with a magnetic coil configured around the neutron beam and between the neutron beam source and the work-piece. The magnetic coil may be used to contain the neutron beams and reduce the scattering of neutron.

Abstract: An object of the invention is to provide a reactor instrumentation system that can be easily repaired or replaced. The invention includes: an instrumentation tube provided in a reactor core; a gas flow pipe provided in the instrumentation tube; a suction mechanism for supplying gas containing oxygen to the gas flow pipe; and a nuclide analysis device for measuring a nuclide in the gas in the gas flow pipe. According to the invention, it is possible to provide a reactor instrumentation system that can be easily repaired or replaced.

Abstract: An arrangement for detecting neutrons. A first neutron detector includes at least some helium, and may include some Helium-3. The first neutron detector has an associated gain performance. A second neutron detector includes at least some helium. The second neutron detector may include some Helium-3 and may include some Helium-4. The second neutron detector has an associated gain performance. In an aspect, the gain performance of the second neutron detector matches the gain performance of the first neutron detector. In an aspect, the amount of all helium of the second detector is the same as the amount of all helium in the first detector. In an aspect, at least one of the first and second detectors includes at least some additional, different neutron-sensitive substance. In an aspect, at least one of the first and second detectors includes some Boron-10 as the additional, different neutron-sensitive substance.

Abstract: A bearing (X) inside which a lubricant is able to be sealed is provided with: a rotary motion body (X2) that moves when a rotation drive force is applied; and a rotation angle indicator (X6) that is provided on the rotary motion body (X2) and that is moved, in conjunction with the movement of the rotary motion body (X2), to a position that corresponds to the rotation angle of the rotary motion body (X2).

Abstract: According to one embodiment of a reactor core monitoring system, includes: an information retention portion for retaining a regular cycle and a short cycle as calculation information of reactor core performance data; a signal processing portion for creating heat balance data based on a process signal; a data acquisition portion for acquiring, in a timing of the regular cycle, the heat balance data and reactor core performance data which was calculated in a previous timing of the regular cycle, while acquiring, in a timing of the short cycle asynchronous to the regular cycle, the heat balance data and reactor core performance data which was calculated most recently; and a data calculation portion for calculating new reactor core performance data based on the acquired reactor core performance data and the heat balance data.

Abstract: The direction of the main axis of a bearing is adjusted by turning a supporting base (12a) that is supporting the bearing, and by then receiving a neutron beam that has been transmitted through the bearing from the direction of the main axis thereof, and converting it into an electromagnetic wave, and by then forming images using the received electromagnetic wave, lubricant distribution data that shows the distribution of a lubricant inside the bearing is acquired.

Abstract: A light emitting element according to one embodiment of the present invention is configured of a metal fluoride crystal which is represented by chemical formula LiM1M2F6 (wherein Li includes 6Li; M1 represents at least one alkaline earth metal element selected from among Mg, Ca, Sr and Ba; and M2 represents at least one metal element selected from among Al, Ga and Sc), said metal fluoride crystal containing 0.02% by mole or more of Eu and having an Eu2+ concentration of less than 0.01% by mole.

Abstract: A neutron detector includes a microchannel plate having a structure that defines a plurality of microchannels, and layers of materials disposed on walls of the microchannels. The layers include a layer of neutron sensitive material, a layer of semiconducting material, and a layer of electron emissive material. For example, the layer of neutron sensitive material can include boron-10, lithium-6, or gadolinium.

Abstract: A gas avalanche neutron detector (GAND) filled with counting gas for detecting thermal neutrons or neutron radiation without the use of a conventional proportional counter is provided. The GAND may include a layer of thermalization material, a cathode having a face with a layer of material, exhibiting neutron capture followed by charged particle emission such as Boron-10, a microstructure amplifier, and an anode. Thermal neutrons may enter the detector and interact with the material on the face of the cathode producing alpha particles. The alpha particles may ionize the counting gas inside the detector and produce ionization electrons. The cathode, microstructure amplifier and anode may have voltages applied that create electric fields that cause the ionization electrons to drift toward the microstructure amplifier. The microstructure then accelerates the electrons causing an avalanche effect within the gas and provides an amplification of the signal dramatically increasing neutron detection sensitivity.

Abstract: A spherical device for detecting neutrons includes a sphere-shaped cathode and a ball-shaped anode. The cathode forms an enclosure filled with an ionising gas. The ionising gas is pure nitrogen. The ionising gas can also be mixed with a quencher. In this case, the quencher may be ethane.

Abstract: A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

Abstract: The invention relates to an improved method for detecting and possibly identifying and/or characterizing nuclear and/or radiological material in a container, vehicle, or on a person, comprising the steps of: a. providing at least one detector, which is capable of detecting radiation events being interrelated to nuclear or radiological material; b. bringing the at least one detector in the vicinity of the container, vehicle or person to be monitored; c. detecting radiation events being interrelated to the container, vehicle or person to be monitored; d. assigning each detected radiation event an individual time stamp in order to generate a time pattern of the detected radiation events; and e. analyzing the time pattern with respect to time correlation structures in order to identify a presence and/or characteristics of the nuclear or radiological material.

Abstract: An instrument for detecting radiation is provided, which comprises an inner core housing a neutron detector, and another core comprising a neutron-moderating material, the instrument further including at least one elongate thermal neutron guide located within the outer core and having an inner end that terminates proximal to the neutron detector. In use, the elongate thermal neutron guide channels thermal neutrons towards the neutron detector. Also provided is a method for using said instrument.

Abstract: A method and apparatus for detecting an isotope. Embodiments can detect radioactive isotopes. Embodiments can utilize a detector that incorporates at least two sub-detectors. Each sub-detector can receive energy from an isotope and create a signal corresponding to the received energy. Each sub-detector can incorporate a detector element, such as a detector element incorporating one or more diodes, a detector element incorporating a crystal, a detector element incorporating a solid-state device, or a detector element incorporating a scintillator. The sub-detectors can be configured such that for each isotope to be detected at least two of the sub-detectors produce different output signals, or readings. In an embodiment, each sub-detector is configured such that when there are at least two sub-detectors exposed to the isotope each of the corresponding readings from the sub-detectors is different from each of the other readings.

Abstract: A neutron measurement apparatus includes: an analog signal processor; a digitizing processor; an FFT calculation processor; and a signal processor. The analog signal processor amplifies alternating current components of detector output signals output from a neutron detector, and filters to remove high frequency components from the output signals, which the digitizing processor digitizes at a constant sampling period in a time series; the FFT calculation processor converts certain of the signals in a time domain from the digitizing processor into signals in a frequency domain, and filters the signals in the frequency domain; and the signal processor selects and extracts signals having required frequency components through the calculation processing on the FFT calculation processor, to calculate power spectral densities of the extracted signals, and to convert the calculated power spectral densities into a neutron measurement value.

Abstract: Scintillator compositions are provided which include a solvent or matrix containing a fluorophore having the formula (I) and/or a fluorophore having the formula (II), wherein R1 and R2, being identical or different, are independently chosen from the group consisting of hydrogen, halogen, alkyl which optionally contains one or more heteroatoms, alkoxy, aryl and alkyne with an aryl end group; R3 is chosen from the group consisting of hydrogen, alkyl which optionally contains one or more heteroatoms, aryl, heterocycle, ether and ester; R4 and R5, being identical or different, are independently chosen from the group consisting of hydrogen, alkyl which optionally contains one or more heteroatoms, aryl, heterocycle, ether and ester, whereby the R4 and R5 groups are optionally combined to one cyclic structure; and R6, if present, is chosen from the group consisting of hydrogen, aryl and alkyl.

Abstract: The invention relates to a method for obtaining information or signatures about the presence or the nature of a nuclear radiation source, especially in a homeland security application, said nuclear radiation source emitting in a time or angle correlated manner at least a first radiation and a second radiation. The method includes the steps of detecting said first radiation with at least one first radiation detector and detecting said second radiation with at least one second radiation detector. The detection of said second radiation is triggered by said detection of said first radiation in a manner that is adapted to the radiation's correlation structure, thereby increasing the signal-to-background ratio for the detection of said second radiation.

Abstract: The present invention provides a method for evaluating the rebound resilience, hardness, or energy loss of polymer materials, capable of sufficiently evaluating the difference in performance between samples with excellent measurement accuracy. The present invention relates to a method for evaluating the rebound resilience, hardness, or energy loss of a polymer material, including irradiating the polymer material with X-rays or neutrons to perform X-ray scattering measurement or neutron scattering measurement.

Abstract: Disclosed is an instrument for detecting neutron backscatter from an object including a source of neutrons (12), a neutron detector (14) capable of detecting thermal neutrons and a housing (10) which is impervious to water and having at least one external operating surface (20) for placing adjacent the object, the source and detector being located within the housing in such a way that the distance between the detector and the operating surface(s) is less than 25 mm and the distance between the detector and any other external surface of the housing is at least 50 mm.

Abstract: A neutron detector for detecting neutrons includes an exterior shell bounding and sealing an interior volume. The exterior shell serves as a cathode. A central structure extends longitudinally within the exterior shell. The central structure serves as an anode and is maintained at a first voltage. The neutron detector includes an insulating portion extending between the central structure and the exterior shell and longitudinally past a shell end of the exterior shell towards a structure end of the central structure. A guard structure extends circumferentially around an outer insulating surface. The guard structure is positioned on the insulating portion between the shell end and the structure end. The guard structure is maintained at a second voltage such that a leakage current on the outer insulating surface is absorbed by the guard structure. A method of detecting neutrons with the neutron detector is also provided.

Abstract: A method and a device examine a sample with radiation emitted from a radiation source, which is directed to the sample carried by a sample holder via a beam-forming unit and detected by a detector and evaluated in an evaluating unit. Prior to the examination of the sample, at least one of the following components, including the radiation source, beam-forming unit, sample holder, detector, and a primary beam stop, are oriented and/or positioned in terms of spatial location in relation to at least one of the other components and/or in relation to a predefined fixed point and/or in relation to the optical path with a control unit via actuating drives. The radiation intensity measured by the detector, in a predefined detector range, and/or a value derived therefrom is used for establishing a control variable conferred from the control unit to the actuating drives assigned to the components.

Abstract: The present invention includes an apparatus and method for neutron radiation detection. The apparatus comprises combining thin walled, boron-coated straw tubes with a plastic moderator material interspersed around the tubes. The method involves using such an apparatus through application of voltage to a central wire running inside the tubes and collecting electrical pulses generated thereby.

Abstract: A method for detecting a neutron includes providing a first voltage to an input electrode of a microchannel plate, providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage, measuring a signal on the output electrode, and detecting a neutron based on a comparison of the signal at the output electrode with a baseline value.

Abstract: A method for determining the spectral and spatial distribution of a braking photon flow along at least one direction in space (x, y, z), characterized in that the method comprises measuring the neutrons resulting from the impact of the braking photons (ph) on at least one conversion target which is moved in the direction (x, y, z) in space. The invention can be used for X-rays, medical imaging, tomography, etc.

Abstract: Scintillator compositions are provided which include a solvent or matrix containing a fluorophore having the formula (I) and/or a fluorophore having the formula (II), wherein R1 and R2, being identical or different, are independently chosen from the group consisting of hydrogen, halogen, alkyl which optionally contains one or more heteroatoms, alkoxy, aryl and alkyne with an aryl end group; R3 is chosen from the group consisting of hydrogen, alkyl which optionally contains one or more heteroatoms, aryl, heterocycle, ether and ester; R4 and R5, being identical or different, are independently chosen from the group consisting of hydrogen, alkyl which optionally contains one or more heteroatoms, aryl, heterocycle, ether and ester, whereby the R4 and R5 groups are optionally combined to one cyclic structure; and R6, if present, is chosen from the group consisting of hydrogen, aryl and alkyl.

Abstract: Disclosed herein are representative embodiments of methods, apparatus, and systems for performing combined neutron and gamma ray radiography. For example, one exemplary system comprises: a neutron source; a set of alpha particle detectors configured to detect alpha particles associated with neutrons generated by the neutron source; neutron detectors positioned to detect at least some of the neutrons generated by the neutron source; a gamma ray source; a set of verification gamma ray detectors configured to detect verification gamma rays associated with gamma rays generated by the gamma ray source; a set of gamma ray detectors configured to detect gamma rays generated by the gamma ray source; and an interrogation region located between the neutron source, the gamma ray source, the neutron detectors, and the gamma ray detectors.

Abstract: Systems and methods for generating X-rays and neutrons using a single linear accelerator are disclosed. Such system and methods may interrogate an object at times with X-rays and at other times with neutrons, e.g., after suspicious material is detected based on the X-rays. A system may include a single linear accelerator for generating first and second electron beams; first and second targets; a magnet configured to control irradiation of the first and second targets by the first and second electron beams; and a controller that (a) causes the linear accelerator to generate the first electron beam and causes the magnet to direct the beam to first target to generate X-rays; and (b) causes the linear accelerator to generate the second electron beam and causes the magnet to direct the beam to the second target to generate neutrons.

Abstract: An apparatus for determining a location of a neutron emitting source includes: a plurality of neutron detectors configured to receive incoming neutrons from an area of interest, each neutron detector being configured to produce an image of a path of light depicting a direction of travel of an incoming neutron; and a central processor coupled to each neutron detector in the plurality of neutron detectors and configured to receive the direction of travel of the incoming neutron from each neutron detector and to compute the location using the received directions.

Abstract: An auxiliary neutron detector apparatus designed for attaching and supplementation to an existing gamma-ray spectrometer adds improved neutron detection capabilities. The apparatus uses the existing detector and so does not require additional detector materials, including 3He, which are required by conventional neutron detector attachments. Because of the cost and limited availability of detector materials, this invention is particularly valuable for upgrading systems without existing neutron detector, and for repairing systems with damaged neutron detectors.

Abstract: A neutron measurement apparatus includes: an analog signal processor; a digitizing processor; an FFT calculation processor; and a signal processor. The analog signal processor amplifies alternating current components of detector output signals output from a neutron detector, and filters to remove high frequency components from the output signals, which the digitizing processor digitizes at a constant sampling period in a time series; the FFT calculation processor converts certain of the signals in a time domain from the digitizing processor into signals in a frequency domain, and filters the signals in the frequency domain; and the signal processor selects and extracts signals having required frequency components through the calculation processing on the FFT calculation processor, to calculate power spectral densities of the extracted signals, and to convert the calculated power spectral densities into a neutron measurement value.

Abstract: Methods and apparatus for a detector system to detect gamma and neutron radiation. In one embodiment, a detector comprises a tank to hold a liquid, a plurality of tubes adjacent the tank to detect neutrons, and a plurality of photon detectors to detect Cherenkov light generated by gamma radiation in the liquid. The tank is configured to contain the liquid so that the liquid generates the Cherenkov light and moderates the neutrons.

Abstract: Neutrons can be detected using first information derived from a first charge induced on an input electrode of a microchannel plate and second information derived from a second charge induced on an output electrode of the microchannel plate. For example, a ratio between the first charge and the second charge is calculated, a sum of the first and second charges is calculated, and whether a neutron has been detected can be determined based on the ratio and the sum.

Abstract: A device includes a neutron-sensitive composition. The composition includes, in weight percent, a non-zero amount of aluminum oxide (e.g., approximately 1% to approximately 3.5% aluminum oxide), greater than 12% (e.g., approximately 12% to approximately 17%) boron oxide, greater than approximately 60% silicon oxide (e.g., approximately 62% to approximately 68% silicon oxide), and a non-zero amount of sodium oxide (e.g., approximately 10% to approximately 14% sodium oxide). The device is capable of interacting with neutrons to form an electron cascade.

Abstract: A 10B neutron detector and an associated method of detecting neutrons. The detector includes an exterior shell bounding and sealing an interior volume, a neutron-sensitive boron coating located on at least part of the exterior shell at the interior volume. One of the boron coating and the exterior shell serves as a cathode, and a central structure located within the interior volume and serves as an anode. The detector includes gas within the interior volume that conducts an electrical energy pulse between the cathode and the anode in response to a neutron impinging upon the neutron-sensitive boron coating. The gas includes a quantity of 3He gas sensitive to neutron impingement and generating an electrical energy pulse for reception by the anode in response to a neutron impinging upon the 3He gas. The method includes detecting at least one neutron via impingement of the neutron upon the 3He gas.

Abstract: A method of determining directionality of radiation is disclosed which comprises dividing the tensioned metastable fluid liquid volume adjacent to a radioactive source into a plurality of sectors, determining the opposing sector ratio of the respective sector and determining the direction of the radiation based on the opposing sector ratios of the plurality of sectors. The method further comprising determining directionality of incoming radiation from the tension pressure assisted elongation of bubble shapes pointing towards direction of radiation particles that interacted with nuclei of tensioned metastable fluid detector system. A device capable of carrying out these methods is also disclosed.

Abstract: To avoid reset noise in a CMOS chip for direct particle counting, it is known to use Correlative Double Sampling: for each signal value, the pixel is sampled twice: once directly after reset and once after an integration time. The signal is then determined by subtracting the reset value from the later acquired value, and the pixel is reset again. In some embodiments of the invention, the pixel is reset only after a large number of read-outs. Applicants realized that typically a large number of events, typically approximately 10, are needed to cause a full pixel. By either resetting after a large number of images, or when one pixel of the image shows a signal above a predetermined value (for example 0.8×the full-well capacity), the image speed can be almost doubled compared to the prior art method, using a reset after acquiring a signal.

Abstract: A neutron detector includes a bulk of a neutron moderating material, a first housing consisting of or comprising a gamma ray attenuating material, a second housing consisting of or comprising a gamma ray attenuating material, a first sensor device comprising a gadolinium cover disposed in the first housing, and a second sensor device disposed in the second housing. The first sensor device and the second sensor device are each sensitive to gamma rays. The first housing and the second housing are arranged adjacent to each other in the bulk.

Abstract: This disclosure relates to systems and methods for material discrimination. The systems and methods include a single source that generates both neutrons and photons, and a single imaging array with a common detector that detects the neutrons and the photons generated from the single source. The systems and methods allow for a determination of the contents, and/or the effective atomic number (“Z”) of the contents, of an object without physical inspection of the interior of the object.

Abstract: Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms.

Abstract: A method for detecting neutron radiation in accordance with particular embodiments includes exposing a neutron detector array comprising at least one two-dimensional array of neutron detectors to a first scene of interest. The neutron detector array is based on at least one two-dimensional array of microbolometer detectors. The method also includes receiving a plurality of response values from a corresponding plurality of neutron detectors of the neutron detector array. The method further includes generating a comparison value based on the plurality of response values and a baseline response value. The method additionally, includes determining whether more than a first threshold amount of neutron radiation is being generated by the first scene based on the comparison value.

Abstract: An instrument that will directly image the fast fission neutrons from a special nuclear material source wherein the neutron detection efficiency is increased has been described. Instead of the previous technique that uses a time-of-flight (TOF) between 2 widely spaced fixed planes of neutron detectors to measure scatter neutron kinetic energy, we now use the recoil proton energy deposited in the second of the 2 scatter planes which can now be repositioned either much closer together or further apart. However, by doubling the separation distance between the 2 planes from 20 cm to a distance of 40 cm we improved the angular resolution of the detector from about 12° to about 10°. A further doubling of the separation distance to 80 cm provided an addition improvement in angular resolution of the detector to about 6° without adding additional detectors or ancillary electronics.

Abstract: A flux detection apparatus can include a radioactive sample having a decay rate capable of changing in response to interaction with a first particle or a field, and a detector associated with the radioactive sample. The detector is responsive to a second particle or radiation formed by decay of the radioactive sample. The rate of decay of the radioactive sample can be correlated to flux of the first particle or the field. Detection of the first particle or the field can provide an early warning for an impending solar event.