Abstract: A method for assessing the mass concentration of uranium in a sample of uranium-bearing material by gamma spectrometry, includes a) acquiring (200) an energy spectrum of gamma radiation from the sample using a scintillator detector, the energy spectrum (100) comprising at least a first energy band (110) between 87 keV and 110 keV, and a second energy band (120) between 560 keV and 660 keV, the second energy band comprising at least one energy line (130) at 609 keV from 214Bi, b) calculating (210) an initial mass concentration of uranium (CmU0) using the energy spectrum, c) measuring (220) a parameter representative of the height of the sample and a parameter representative of the density of the sample, d) calculating (230) a corrective coefficient (K), and e) calculating (240) a corrected mass concentration of uranium (CmU) using the initial mass concentration of uranium (CmU0) and the corrective coefficient (K).

Abstract: A method for assessing the mass concentration of uranium in a sample of uranium-bearing material by gamma spectrometry, includes a) acquiring (200) an energy spectrum of gamma radiation from the sample using a scintillator detector, the energy spectrum (100) comprising at least a first energy band (110) between 87 keV and 110 keV, and a second energy band (120) between 560 keV and 660 keV, the second energy band comprising at least one energy line (130) at 609 keV from 214Bi, b) calculating (210) an initial mass concentration of uranium (CmU0) using the energy spectrum, c) measuring (220) a parameter representative of the height of the sample and a parameter representative of the density of the sample, d) calculating (230) a corrective coefficient (K), and e) calculating (240) a corrected mass concentration of uranium (CmU) using the initial mass concentration of uranium (CmU0) and the corrective coefficient (K).

Abstract: A device for measuring an amount of beryllium in a radioactive object, including: a hollow cylinder of a first piece made of a material to thermalize neutrons emitted by the radioactive object and a metal piece to mitigate a dose rate on the radioactive object, the first piece having a hollow cylinder shape deprived of a wall fraction, the metal piece including a solid part inserted in a space which corresponds to the deprived wall fraction of the first piece and a recessed part which is an extension of the solid part and is accommodated within the wall of the first piece, in contact with the first piece; a gamma radiation source accommodated in an indentation of the recessed part of the metal piece; and at least one neutron detector placed in a bulk of the first piece.

Abstract: A device for measuring an amount of beryllium in a radioactive object, including: a hollow cylinder of a first piece made of a material to thermalize neutrons emitted by the radioactive object and a metal piece to mitigate a dose rate on the radioactive object, the first piece having a hollow cylinder shape deprived of a wall fraction, the metal piece including a solid part inserted in a space which corresponds to the deprived wall fraction of the first piece and a recessed part which is an extension of the solid part and is accommodated within the wall of the first piece, in contact with the first piece; a gamma radiation source accommodated in an indentation of the recessed part of the metal piece; and at least one neutron detector placed in a bulk of the first piece.

Abstract: A method for detecting the presence of a chemical element in an object by emission of neutrons onto the object, characterized in that the emission of neutrons onto the object is constituted, firstly, by a continuous emission of neutrons originating from an associated particle neutron generator (G1) and, secondly, by an emission of neutron pulses which are superimposed on the continuous emission of neutrons, where the neutron pulses originate from a pulsed neutron generator (G2) which generates neutron pulses of pulse duration T2, where two successive neutron pulses are separated by a duration T4, and where the continuous and pulsed emissions of neutrons on to the object produce a gamma capture radiation and an inelastic gamma radiation.

Abstract: A method for detecting nuclear material in an object analysed by neutron interrogation with an associated particle tube, where the method includes steps of detection of coinciding pulses by detector pixels of at least one matrix of detector pixels, where a step of detection of coinciding pulses leads to the formation of an event which reflects a fission reaction which occurs in the nuclear material, where the method includes a search for adjoining pixels amongst the pixels which have detected coinciding pulses, a grouping of adjoining pixels into groups of adjoining pixels, a count of the pixels and/or groups of adjoining pixels which have detected coinciding pulses, and a validation of the occurrence of an event provided at least three pixels and/or groups of adjoining pixels are counted.

Abstract: A method for detecting the presence of a chemical element in an object by emission of neutrons onto the object, characterized in that the emission of neutrons onto the object is constituted, firstly, by a continuous emission of neutrons originating from an associated particle neutron generator (G1) and, secondly, by an emission of neutron pulses which are superimposed on the continuous emission of neutrons, where the neutron pulses originate from a pulsed neutron generator (G2) which generates neutron pulses of pulse duration T2, where two successive neutron pulses are separated by a duration T4, and where the continuous and pulsed emissions of neutrons on to the object produce a gamma capture radiation and an inelastic gamma radiation.