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: A system and method for producing images of the structure and composition of an object based on measurements of the low-angle x-ray diffraction properties of the object. The imaging system includes a coded aperture that encodes spatial and spectral features onto radiation scattered from image points within the object. The radiation is detected at a two-dimensional array of detectors, whose output is deconvolved and processed to estimate a three-dimensional image having molecular specificity.

Abstract: Identification of a material composition. The material composition is configured with a color additive that is embedded or otherwise not visible. The color additive identifies the specific material composition. A discrete section or sub-section of the material is deformed such that the embedded color additive is made visible in the optical spectrum, after which the discrete section or sub-section may be sorted for recycling.

Abstract: A photoneutron conversion target for generating photoneutrons by directing an x-ray beam at the photoneutron conversion target includes an elongated body having a first end and a second end. When the photoneutron conversion target is in use, the x-ray beam enters the body and propagates in a direction from the first end to the second end. The body of the photoneutron conversion target is shaped such that propagation of the x-ray beam is substantially proportionate to an intensity distribution of the x-ray beam, so that the greater an intensity of x-rays of the x-ray beam, the greater the propagation distance of the x-rays within the body of the photoneutron conversion target. The photoneutron conversion target according to the invention can make full use of the x-ray beam so as to increase a yield of photoneutrons.

Abstract: Methods and systems for non-intrusively detecting the existence of fissile materials in a container via the measurement of energetic prompt neutrons are disclosed. The methods and systems use the unique nature of the prompt neutron energy spectrum from photo-fission arising from the emission of neutrons from almost fully accelerated fragments to unambiguously identify fissile material. The angular distribution of the prompt neutrons from photo-fission and the energy distribution correlated to neutron angle relative to the photon beam are used to distinguish odd-even from even-even nuclei undergoing photo-fission. The independence of the neutron yield curve (yield as a function of electron beam energy or photon energy) on neutron energy also is also used to distinguish photo-fission from other processes such as (?, n). Different beam geometries are used to detect localized samples of fissile material and also fissile materials dispersed as small fragments or thin sheets over broad regions.

Abstract: Methods and systems for non-intrusively detecting the existence of fissile materials in a container via the measurement of energetic prompt neutrons are disclosed. The methods and systems use the unique nature of the prompt neutron energy spectrum from photo-fission arising from the emission of neutrons from almost fully accelerated fragments to unambiguously identify fissile material. The angular distribution of the prompt neutrons from photo-fission and the energy distribution correlated to neutron angle relative to the photon beam are used to distinguish odd-even from even-even nuclei undergoing photo-fission. The independence of the neutron yield curve (yield as a function of electron beam energy or photon energy) on neutron energy also is also used to distinguish photo-fission from other processes such as (?, n). Different beam geometries are used to detect localized samples of fissile material and also fissile materials dispersed as small fragments or thin sheets over broad regions.

Abstract: A method and system for detecting special nuclear materials are disclosed. Said method and system detect the special nuclear materials by making use of the photofission characteristic and thermal neutron induced fission characteristic thereof. In one preferred embodiment, the high density and/or high atomic number region in the object to be detected is also detected first as a suspicious region.

Abstract: Apparatus for generating thermal neutrons includes an electron accelerator for generating an electron beam and a converter for converting the electron beam into photons. A receiving device is provided for receiving the photons and includes a material which provides a photoneutron target for the photons, for producing high energy neutrons in a photonuclear reaction between the photons and the photoneutron target, and for moderating the high energy neutrons to generate the thermal neutrons. The electron beam has an energy level high enough to produce photons of sufficient energy to exceed the photodissociation threshold of the selected target material, but that is sufficiently low as to enable the material to moderate the high energy neutrons resulting from the photonuclear reaction.

Abstract: Methods for detecting and identifying carbon- and/or nitrogen-containing materials are disclosed. The methods may comprise detection of photo-nuclear reaction products of nitrogen and carbon to detect and identify the carbon- and/or nitrogen-containing materials.

Abstract: The present invention provides a method for producing Cu67 radioisotope suitable for use in medical applications. The method comprises irradiating a metallic zinc-68 (Zn68) target with a high energy gamma ray beam. After irradiation, the Cu67 is isolated from the Zn68 by any suitable method (e.g., chemical and/or physical separation). In a preferred embodiment, the Cu67 is isolated by sublimation of the zinc (e.g., at about 500-700° C. under reduced pressure) to afford a copper residue containing Cu67. The Cu67 can be further purified by chemical means (i.e., dissolution in acid, followed by ion exchange).

Abstract: A method is described for producing a radionuclide product B. A target is provided which includes an amount of a nuclide A. A gamma (?) beam from Compton back-scattering of laser light from an electron beam irradiates the target and thereby transmutes at least a portion of the amount of the nuclide A into the product B. Providing the target includes selecting a nuclide A which is transmutable into product B by a gamma (?) induced nuclear reaction.

Abstract: A method and apparatus for identifying and tagging a target, such an individual or an item, are described that provide an improved mechanism for identifying the target without alerting the target. In this regard, a method and apparatus can irradiate the target so as to create a radioisotope signature for the target. By thereafter monitoring the radioisotope signature, the target can be identified and tracked in a covert manner.

Abstract: The ion acceleration system or complex (T) for medical and/or other applications is composed in essence by an ion source (1), a pre-accelerator (3) and one or more linear accelerators or linacs (6, 8, 10, 13), at least one of which is mounted on a rotating mechanical gantry-like structure (17). The isocentrical gantry (17) is equipped with a beam delivery system, which can be either ‘active’ or ‘passive’, for medical and/or other applications. The ion source (1) and the pre-accelerator (3) can be either installed on the floor, which is connected with the gantry basement, or mounted, fully or partially, on the rotating mechanical structure (17). The output beam can vary in energy and intensity pulse-by-pulse by adjusting the radio-frequency field in the accelerating modules of the linac(s) and the beam parameters at the input of the linear accelerators.

Abstract: A system for detecting and classifying small amounts of explosives and other controlled substances while rejecting confounders, including a source/detector array formed of a plurality of sources and a plurality of detectors, a signal processor coupled to the source/detector array for processing data received from the detectors, a classifier coupled to the signal processor for classifying data received from the signal processor according to a plurality of algorithms, a maximal rejection classifier coupled to the classifier; and a declarative decision module coupled to the maximal rejection classifier for rendering an accurate decision regarding the contents of the object is provided. The apparatus includes an enclosure, a shield layer disposed within the enclosure, a cavity disposed within the shield layer, a plurality of neutron sources and a detection array disposed within the cavity, and a transport mechanism for moving objects through the cavity past the sources and detection array.

Abstract: Systems and methods for detecting clandestine fissile or radioactive material on the basis of emitted radiation and particles (such as neutrons and alpha particles) arising from within the material. Emission by the fissile or radioactive material is detected in conjunction with a conventional x-ray imaging system that includes an external source of illuminating penetrating radiation, at least one detector configured to detect at least the penetrating radiation and to generate a detector signal, and a processor configured as a detector signal discriminator to generate an output indicating whether the detector signal is triggered by an origin other than illuminating penetrating radiation. Active and passive modes of detection are described by some embodiments. Other embodiments are directed toward neutron detection, gamma ray detection with energy resolution, and designs of detectors to enhance the detection of clandestine nuclear material.

Abstract: Using the device and method of the present invention, high energy photons, or gamma radiation, impinge upon a target comprising a nanomaterial that includes a target isotope, resulting in the release of one or more neutrons from the target isotope. This neutron release creates an effect known as “kinematic recoil,” which results in a recoiling photo-produced radioisotope which is ejected from the nanomaterial and can be harvested in high specific activity.

Abstract: The invention relates to nuclear technology, and to irradiation targets and their preparation. One embodiment of the present invention includes a method for preparation of a target containing intermetallic composition of antimony Ti—Sb, Al—Sb, Cu—Sb, or Ni—Sb in order to produce radionuclides (e.g., tin-117 m) with a beam of accelerated particles. The intermetallic compounds of antimony can be welded by means of diffusion welding to a copper backing cooled during irradiation on the beam of accelerated particles. Another target can be encapsulated into a shell made of metallic niobium, stainless steel, nickel or titanium cooled outside by water during irradiation. Titanium shell can be plated outside by nickel to avoid interaction with the cooling water.

Abstract: A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

Abstract: Apparatus and method for detecting forgery by neutron activation of art objects or other valuables such as bonds, wills, etc. comprising of a device applying neutron irradiation to a reference spot sufficient to produce radiation including gamma rays; immediately thereafter, a device and method of the invention determines and records the rate of emission as a function of time that results from the application of the thermal neutron irradiation to the reference spot and produces ‘initial’ data thereof; at one or several selected subsequent intervals thereafter, the device and method determines and records the quantitative measures of the radiation emission in the gamma ranges of energy emanating from the reference spot taken at time intervals after activation and produces ‘subsequent’ data, and a device and method compares ‘initial’ data with ‘subsequent’ data.

Abstract: Methods for detecting and identifying carbon- and/or nitrogen-containing materials are disclosed. The methods may comprise detection of photo-nuclear reaction products of nitrogen and carbon to detect and identify the carbon- and/or nitrogen-containing materials.

Abstract: A method for determining the intensity I(Ech1) of gamma radiation of a radioelement from the known intensity I(Ech2) of gamma radiation of a standard radioelement, characterised in that it includes a step for calculating the intensity I(Ech1) as: I ? ( Ech 1 ) = ( S ? ( Ech 1 ) S ? ( Ech 2 ) ? R 2 R 1 ? C d ? ? 2 C d ? ? 1 ? ? ? ? ? 2 ? ? ? ? 1 ? W A , 1 W A , 2 ) ? I ? ( Ech 2 ) where S(Ech1) is the net area of the gamma radiation of the radioelement, S(Ech2) is the net area of the gamma radiation of the standard radioelement, R1 and R2 are respectively a total absorption efficiency of the radiation detector used for measuring S(Ech1) and of the radiation detector used for measuring S(Ech2), ??1 and ??2 are measurements of reactivity variation of a nuclear reactor measured by the oscillation technique, and relating respectively to the radioelement and the standard radioelement, WA,1 and WA,2 are respectively the neutron

Abstract: Example embodiments and methods are directed to irradiation target retention devices that may be inserted into conventional nuclear fuel rods and assemblies. Example embodiment devices may hold several irradiation targets for irradiation during operation of a nuclear core containing the assemblies and fuel rods having example embodiment irradiation target retention devices. Irradiation targets may substantially convert to useful radioisotopes upon exposure to neutron flux in the operating nuclear core and be removed and harvested from fuel rods after operation.

Abstract: Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

Abstract: Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

Abstract: The present invention is related to a device and a method for producing a radioisotope of interest from a target fluid irradiated with a beam of accelerated charged particles, the device includes in a circulation circuit (17): an irradiation cell (1) having a metallic insert (2) able to form a cavity (8) designed to house the target fluid and closed by an irradiation window (7), the cavity (8) including at least one inlet (4) and at least one outlet (5); a pump (16) for circulating the target fluid inside the circulation circuit (17); an external heat exchanger (15); the pump (16) and the external heat exchanger (15) forming external cooling means of the target fluid; the device means for pressurizing (14) of the circulation circuit (17) and the external cooling means of the target fluid are arranged in such a way that the target fluid remains inside the cavity (8) essentially in the liquid state during the irradiation.

Abstract: A method for producing 229Th includes the steps of providing 226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form 229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1×1013 n s?1·cm?2. 228Ra can also be bombarded with thermal and/or energetic neutrons to result in a neutron capture reaction to form 229Th. Using 230Th as a target material, 229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

Abstract: The present invention relates to targets, systems and methods for the cyclotron production of 124I from aluminum telluride (Al2Te3) targets. The systems and methods utilize low energy proton cyclotrons to produce 124I by the 124Te(p,n) reaction from enriched Al2Te3 glassy melts. The 124I is recovered in high yield from the glassy melt by adapted methods of common thermal distillation techniques.

Abstract: The present invention is directed to a defect imaging device that has an energy beam that is directed at a device under test. The energy beam creates positrons deep within the material of the device under test. When the positrons combine with electrons in the material they produce a pair of annihilation photons. The annihilation photons are detected. The Doppler broadening of the annihilation photons is used to determine if a defect is present in the material. Three dimensional images of the device under test are created by directing the energy beam at different portions of the device under test.

Abstract: A method for evaluating a material specimen comprises: Mounting a neutron source and a detector adjacent the material specimen; bombarding the material specimen with neutrons from the neutron source to create prompt gamma rays within the material specimen, some of the prompt gamma rays being emitted from the material specimen, some of the prompt gamma rays resulting in the formation of positrons within the material specimen by pair production; collecting positron annihilation data by detecting with the detector at least one emitted annihilation gamma ray resulting from the annihilation of a positron; storing the positron annihilation data on a data storage system for later retrieval and processing; and continuing to collect and store positron annihilation data, the continued collected and stored positron annihilation data being indicative of an accumulation of lattice damage over time.

Abstract: A dual neutron-gamma ray source comprises a compact neutron generator, a shield, a collimator, and an internal gamma target. The shield surrounds the compact neutron generator. The collimator traverses the shield from the compact neutron generator to a collimator port. The internal gamma target is positioned within the collimator to generate gamma rays from the neutrons.

Abstract: A variable-ratio neutron-gamma ray source comprises a neutron generator, a shield, a collimator, and an external gamma target. The neutron generator generates neutrons and the shield reduces external radiation exposure. The collimator collimates the neutrons into a neutron beam that traverses the shield. The external gamma target generates a dual neutron-gamma ray beam from the neutron beam, wherein the dual neutron-gamma ray beam has a variable neutron-gamma ratio as a function of a thickness of the external gamma target.

Abstract: A remote sensing device for detecting materials of varying atomic numbers and systems and methods relating thereto. A system for identifying a material includes a photon beam flux monitor for resolving a high-energy beam. A method for identifying a material includes casting an incident photon beam on the material and detecting an emerging photon beam with an array of fission-fragment detectors, a first set of scintillator paddles, and a second set of scintillator paddles.

Abstract: A concentrated irradiation type radiotherapy apparatus comprises a radiation source, a multi-channeled radiation detector, a rotating mechanism, an image reconstruction unit, a multi-leaf collimator disposed between the radiation source and the subject to trim the radioactive rays in arbitrary shapes and including a plurality of first leaves and a plurality of second leaves each disposed to be individually movable forwards/backwards and each having a strip shape and in which types of the first leaves are different from those of the second leaves.

Abstract: Systems and methods for detecting clandestine fissile or radioactive material on the basis of emitted radiation and particles (such as neutrons and alpha particles) arising from within the material. Emission by the fissile or radioactive material is detected in conjunction with a conventional x-ray imaging system that includes an external source of illuminating penetrating radiation, at least one detector configured to detect at least the penetrating radiation and to generate a detector signal, and a processor configured as a detector signal discriminator to generate an output indicating whether the detector signal is triggered by an origin other than illuminating penetrating radiation. Active and passive modes of detection are described by some embodiments. Other embodiments are directed toward neutron detection, gamma ray detection with energy resolution, and designs of detectors to enhance the detection of clandestine nuclear material.

Abstract: A system for detecting and classifying small amounts of explosives and other controlled substances while rejecting confounders, including a source/detector array formed of a plurality of sources and a plurality of detectors, a signal processor coupled to the source/detector array for processing data received from the detectors, a classifier coupled to the signal processor for classifying data received from the signal processor according to a plurality of algorithms, a maximal rejection classifier coupled to the classifier; and a declarative decision module coupled to the maximal rejection classifier for rendering an accurate decision regarding the contents of the object is provided. The apparatus includes an enclosure, a shield layer disposed within the enclosure, a cavity disposed within the shield layer, a plurality of neutron sources and a detection array disposed within the cavity, and a transport mechanism for moving objects through the cavity past the sources and detection array.

Abstract: A biomarker generator system for producing approximately one (1) unit dose of a biomarker. The biomarker generator system includes a small, low-power particle accelerator (“micro-accelerator”) and a radiochemical synthesis subsystem having at least one microreactor and/or microfluidic chip. The micro-accelerator is provided for producing approximately one (1) unit dose of a radioactive substance, such as a substance that emits positrons. The radiochemical synthesis subsystem is provided for receiving the radioactive substance, for receiving at least one reagent, and for synthesizing the approximately one (1) unit dose of a biomarker.

Abstract: A method of covertly tagging an object for later tracking includes providing a material capable of at least one of being applied to the object and being included in the object, which material includes deuterium; and performing at least one of applying the material to the object and including the material in the object in a manner in which in the appearance of the object is not changed, to the naked eye.

Abstract: Non-destructive testing apparatus according to one embodiment of the invention comprises a photon source. The photon source produces photons having predetermined energies and directs the photons toward a specimen being tested. The photons from the photon source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested detects gamma rays produced by annihilation of positrons with electrons. A data processing system operatively associated with the detector produces output data indicative of a lattice characteristic of the specimen being tested.

Abstract: A non-destructive testing method comprises providing a specimen having at least one positron emitter therein; determining a threshold energy for activating the positron emitter; and determining whether a half-life of the positron emitter is less than a selected half-life. If the half-life of the positron emitter is greater than or equal to the selected half-life, then activating the positron emitter by bombarding the specimen with photons having energies greater than the threshold energy and detecting gamma rays produced by annihilation of positrons in the specimen. If the half-life of the positron emitter is less then the selected half-life, then alternately activating the positron emitter by bombarding the specimen with photons having energies greater then the threshold energy and detecting gamma rays produced by positron annihilation within the specimen.

Abstract: An apparatus and method for irradiating target objects, especially medical stents for in vivo implantation. A linear accelerator provides a high energy electron beam that impinges upon and is received by an x-ray conversion target. The x-ray conversion target is activated by either a static or dynamically moveable electron beam to generate and emit an x-ray flux so as to efficiently intercept the target object. The x-ray flux is directed to the target object for a desired time period and is of sufficiently high energy to efficiently impart radioactive properties to the target object. Alternatively, the target object is positioned within the path of the x-ray flux or is translated within the path during irradiation. Mechanical transport assemblies such as a carousel, rotational and/or linear translator and/or movement tube system also may be provided.

Abstract: The subject apparatus provides a means to identify the presence of fissionable material or other nuclear material contained within an item to be tested. The system employs a portable accelerator to accelerate and direct protons to a fluorine-compound target. The interaction of the protons with the fluorine-compound target produces gamma rays which are directed at the item to be tested. If the item to be tested contains either a fissionable material or other nuclear material the interaction of the gamma rays with the material contained within the test item with result in the production of neutrons. A system of neutron detectors is positioned to intercept any neutrons generated by the test item. The results from the neutron detectors are analyzed to determine the presence of a fissionable material or other nuclear material.

Abstract: A concentrated irradiation type radiotherapy apparatus comprises a radiation source, a multi-channeled radiation detector, a rotating mechanism, an image reconstruction unit, a multi-leaf collimator disposed between the radiation source and the subject to trim the radioactive rays in arbitrary shapes and including a plurality of first leaves and a plurality of second leaves each disposed to be individually movable forwards/backwards and each having a strip shape and in which types of the first leaves are different from those of the second leaves.

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 method for evaluating a material specimen according to one embodiment of the present invention may comprise: Bombarding the material specimen with neutrons to create prompt gamma rays within the material specimen, some of the prompt gamma rays being emitted from the material specimen, some of the prompt gamma rays resulting in the formation of positrons within the material specimen by pair production; detecting at least one emitted prompt gamma ray; detecting at least one emitted annihilation gamma ray resulting from the annihilation of a positron; and calculating positron lifetime data based on the detected emitted prompt gamma ray and the detected emitted annihilation gamma ray.

Abstract: A method for detecting an explosive in an object under investigation involves the initial X-ray irradiation of the object under investigation, e.g. a piece of luggage or mailing, and forming its X-ray images; using the X-ray images to detect areas with a high density of organic materials and identifying articles therein; determining the location, dimensions and supposed mass of an unidentified article; determining and forming a directional pattern of the neutron radiator corresponding to the dimensions of the unidentified article. The method further includes subsequent thermal neutron irradiation of the area with the unidentified article; recording gamma-ray quanta having the energy of 10.8 MeV and cascade gamma-ray quanta with energies of 5.534 and 5.

Abstract: Non-destructive testing apparatus according to one embodiment of the invention comprises a photon source. The photon source produces photons having predetermined energies and directs the photons toward a specimen being tested. The photons from the photon source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested detects gamma rays produced by annihilation of positrons with electrons which are indicative of a material characteristic of the specimen being tested.

Abstract: Non-destructive testing apparatus according to one embodiment of the invention comprises a photon source. The photon source produces photons having predetermined energies and directs the photons toward a specimen being tested. The photons from the photon source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested detects gamma rays produced by annihilation of positrons with electrons which are indicative of a material characteristic of the specimen being tested.

Abstract: A method for reducing radioactivity in a radioactive sample is disclosed, comprising contacting said sample with a beam of photons, said beam having an energy level sufficient to cause said radioactive sample to emit particles including photons in an amount sufficient to accelerate a reduction in radioactivity of said sample. Also disclosed is a method of increasing radioactive decay in a radioactive isotope comprising the steps of: determining a beam of an effective energy and effective flux of photons to increase radioactive decay in the radioactive isotope; applying the beam to the radioactive isotope; and maintaining the beam for an amount of time effective to increase the radioactivity of the radioactive isotope.

Abstract: The invention relates a device for measuring the relative proportions of uranium and plutonium in a radioactive package (16), having: a source of photons (10) for irradiating the package, at least one delayed neutron detector (18) able to deliver counting signals for neutrons emitted by the package, means (22, 30) of acquiring counting signals, able to establish a decrease over time in the neutrons emitted, characteristic of the radioactive package, calculation means (32) for comparing the decay characteristic of the radioactive package with the respective characteristic decays of uranium and plutonium and for establishing relative proportions of uranium and plutonium in the package.

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