Abstract: A method for determining a response of a spectrometric system for measuring ionizing x-ray or gamma-ray photons, the measuring system comprising: a radiation source, configured to emit ionizing radiation along an emission axis; a pixelated detector, which comprises pixels, each pixel being configured to detect radiation emitted by the radiation source, and to acquire thereof an energy spectrum, in a plurality of energy channels; the emission axis being an axis extending between the radiation source and the detector; the response of the measuring system taking the form of effective spectra, defined for each pixel, and in each energy band, the effective spectrum of a pixel, in an energy band, corresponding to an energy distribution of the photons detected, by the pixel, in the energy channel, in the absence of any object interposed between the source and the pixel.

Abstract: A method for determining the degree of polymerization of a polymer is disclosed, the polymer being contained in a sample (2), the method comprising the following steps: a) illuminating the sample (2) using a laser beam (11) and acquiring (100) a Raman spectrum (S) representative of the polymer; b) identifying (110) a peak of interest (Pi) and determining (120) a position (vi) of the peak of interest in the Raman spectrum; c) on the basis of the position of the peak of interest, using a calibration function (ƒ) to determine a degree of polymerization (DP, DE) of the polymer, the calibration function expressing a variation in the position of the peak of interest as a function of the degree of polymerization of the polymer.

Abstract: A method for determining a response of a spectrometric system for measuring ionizing x-ray or gamma-ray photons, the measuring system comprising: a radiation source, configured to emit ionizing radiation along an emission axis; a pixelated detector, which comprises pixels, each pixel being configured to detect radiation emitted by the radiation source, and to acquire thereof an energy spectrum, in a plurality of energy channels; the emission axis being an axis extending between the radiation source and the detector; the response of the measuring system taking the form of effective spectra, defined for each pixel, and in each energy band, the effective spectrum of a pixel, in an energy band, corresponding to an energy distribution of the photons detected, by the pixel, in the energy channel, in the absence of any object interposed between the source and the pixel.

Abstract: The invention is a method for characterizing an object (20), comprising the following steps: a) placing the object between a radiation source (10) and a radiation detector (30); b) irradiating the object with the radiation source and detecting radiation transmitted by the object (14) using the radiation detector, the radiation detector defining a plurality of pixels; c) for each pixel (30i), forming an energy spectrum (Si) of the detected radiation, each spectrum comprising at least two distinct energy bands; d) from each spectrum formed in c), estimating, in each pixel, at least two equivalent thicknesses ({circumflex over (L)}i,1 . . . {circumflex over (L)}i,M,{circumflex over (L)}?i,1 . . . {circumflex over (L)}?i,M) respectively associated with at least two basic materials (mat1 . . . matM,mat?1 . . .

Abstract: A method for determining the degree of polymerization of a polymer is disclosed, the polymer being contained in a sample (2), the method comprising the following steps: a) illuminating the sample (2) using a laser beam (11) and acquiring (100) a Raman spectrum (S) representative of the polymer; b) identifying (110) a peak of interest (Pi) and determining (120) a position (vi) of the peak of interest in the Raman spectrum; c) on the basis of the position of the peak of interest, using a calibration function (ƒ) to determine a degree of polymerization (DP, DE) of the polymer, the calibration function expressing a variation in the position of the peak of interest as a function of the degree of polymerization of the polymer.

Abstract: The invention is an iterative method for acquiring a spectrum of a particle that is subjected to an illumination. It may in particular be a Raman spectrum. The method includes successively acquiring spectra that are what are called elementary spectra. These elementary spectra are combined to form a combined spectrum, which may be obtained by summing said elementary spectra. With each elementary spectrum is associated an acceptance criterion that is representative of a variation between said elementary spectrum and the elementary spectra acquired beforehand. Depending on this acceptance criterion, the elementary spectrum is either rejected, or accepted, in which case it is added to the combined spectrum. The invention makes it possible to guard against a degradation of the particle under the effect of an excessive exposure to said illumination.

Abstract: The invention is a method for characterizing an object (20), comprising the following steps: a) placing the object between a radiation source (10) and a radiation detector (30); b) irradiating the object with the radiation source and detecting radiation transmitted by the object (14) using the radiation detector, the radiation detector defining a plurality of pixels; c) for each pixel (30i), forming an energy spectrum (Si) of the detected radiation, each spectrum comprising at least two distinct energy bands; d) from each spectrum formed in c), estimating, in each pixel, at least two equivalent thicknesses ({circumflex over (L)}i,1 . . . {circumflex over (L)}i,M,{circumflex over (L)}?i,1 . . . {circumflex over (L)}?i,M) respectively associated with at least two basic materials (mat1 . . . matM,mat?1 . . .

Abstract: The invention relates to a method for linearizing attenuation measurements obtained by means of a direct conversion spectrometer. The spectrometer comprises a radiation source and a detector for detecting said radiation after it has passed through an object. An attenuation measurement is represented by a vector Md giving the attenuation of the radiation in a plurality Nk of energy channels of the detector, said spectrometer being characterized by a response matrix ?. Said method estimates, by means of an iterative process, a vector Mlin, called an equivalent linear attenuation vector, giving for each energy channel an attenuation linearly depending on the thickness of the material through which the radiation passes. Said method is applicable to the characterization of the material as well as to the reduction of artifacts in computed tomography.

Abstract: The invention is an iterative method for acquiring a spectrum of a particle that is subjected to an illumination. It may in particular be a Raman spectrum. The method includes successively acquiring spectra that are what are called elementary spectra. These elementary spectra are combined to form a combined spectrum, which may be obtained by summing said elementary spectra. With each elementary spectrum is associated an acceptance criterion that is representative of a variation between said elementary spectrum and the elementary spectra acquired beforehand. Depending on this acceptance criterion, the elementary spectrum is either rejected, or accepted, in which case it is added to the combined spectrum. The invention makes it possible to guard against a degradation of the particle under the effect of an excessive exposure to said illumination.

Abstract: The invention relates to a method for processing energy spectra of a radiation transmitted by an object irradiated by a source of ionizing radiations, in particular an X radiation, for applications in medical imaging or non-destructive inspection. The method implements a detector comprising a plurality of pixels, each pixel being able to establish a spectrum of the radiation transmitted by the object. The method makes it possible, from a plurality of spectra detected, to establish so-called corrected spectra. Each corrected spectrum is an estimation of the spectrum of a radiation, called primary radiation, transmitted by the object. The invention makes it possible to reduce the influence of the scattering, by the object, of the spectrum emitted by the source.

Abstract: A method for characterizing nature of a material, including: providing at least one sample of the material between an X-ray source and a detector; using the X-ray source to make N X-radiation spectra transmitted through the material, each for a time; calculating transmission function of the material as a function of energy or the detection channel; and in each of at least two energy zones, calculating the integral of the transmission function, thus forming at least a first transmission coefficient and a second transmission coefficient.

Abstract: The invention relates to a method for processing energy spectra of a radiation transmitted by an object irradiated by a source of ionizing radiations, in particular an X radiation, for applications in medical imaging or non-destructive inspection. The method implements a detector comprising a plurality of pixels, each pixel being able to establish a spectrum of the radiation transmitted by the object. The method makes it possible, from a plurality of spectra detected, to establish so-called corrected spectra. Each corrected spectrum is an estimation of the spectrum of a radiation, called primary radiation, transmitted by the object. The invention makes it possible to reduce the influence of the scattering, by the object, of the spectrum emitted by the source.

Abstract: A method identifying a material, includes: measuring an electromagnetic radiation spectrum emitted through the material; determining at least one measurement energy band, and spectral coefficients of a comparison function in the measurement band, using the measured spectrum; estimating, using the determined spectral coefficients, a nature and/or thickness of the material based on a set of reference spectral parameters relating to reference materials and/or thicknesses and defined in reference bands.

Abstract: A calibration method for a device for identifying materials using X-rays, including: a) determining at least one calibration material and, for each calibration material, at least one calibration thickness of this material, b) measuring, for each of the calibration materials and for each of the selected calibration thicknesses, attenuation or transmission coefficients for X radiation, c) calculating statistical parameters from the coefficients, d) determining or calculating, for each calibration material and for each calibration thickness, a presence probability distribution law, as a function of the statistical parameters.

Abstract: The invention relates to a method for linearizing attenuation measurements obtained by means of a direct conversion spectrometer. The spectrometer comprises a radiation source and a detector for detecting said radiation after it has passed through an object. An attenuation measurement is represented by a vector Md giving the attenuation of the radiation in a plurality Nk of energy channels of the detector, said spectrometer being characterized by a response matrix ?. Said method estimates, by means of an iterative process, a vector Mlin, called an equivalent linear attenuation vector, giving for each energy channel an attenuation linearly depending on the thickness of the material through which the radiation passes. Said method is applicable to the characterization of the material as well as to the reduction of artifacts in computed tomography.

Abstract: A photonic radiation detection device includes a collimator, a detector, and localization means for determining information relative to the localization of a photon interaction with the detector material. In at least one previously selected acquisition configuration, a degree of pixelation in the detection plane is greater than 1 and a collimator-detector distance (C) is greater than one tenth of the septal height (h) of the collimator where the septal height is a maximum dimension of the collimator in a direction orthogonal to the frontal detection plane. In one instance, the septal wall thickness (e) is one of about 0.1 or less than about 0.1 of the channel width (w). In another instance, the collimator-detector distance is greater than h/(2(w/e?1)). A dimensioning method includes, for at least one given spatial frequency, calculating and comparing merit indicator values for different acquisition configurations of a structural model of the detection device.

Abstract: A photonic radiation detection device includes a collimator, a detector, means for localization in the detection plane defining on the one hand the partitioning of the detection plane in physical or virtual pixels of transversal dimensions smaller than those of the collimator channels, and associating on the other hand one of said pixels to each photon interaction. The detection device has at least in one previously selected acquisition configuration, a degree of pixelation in the detection plane greater than 1 and a collimator-detector distance (c) greater than one tenth of the septal height (h) of the collimator. A method for dimensioning such a device includes, for at least one given spatial frequency, calculating and comparing merit indicator values for different acquisition configurations of a structural model of the detection device.

Abstract: A method identifying a material, includes: measuring an electromagnetic radiation spectrum emitted through the material; determining at least one measurement energy band, and spectral coefficients of a comparison function in the measurement band, using the measured spectrum; estimating, using the determined spectral coefficients, a nature and/or thickness of the material based on a set of reference spectral parameters relating to reference materials and/or thicknesses and defined in reference bands.

Abstract: A calibration method for a device for identifying materials using X-rays, including: a) determining at least one calibration material and, for each calibration material, at least one calibration thickness of this material, b) measuring, for each of the calibration materials and for each of the selected calibration thicknesses, attenuation or transmission coefficients for X radiation, c) calculating statistical parameters from the coefficients, d) determining or calculating, for each calibration material and for each calibration thickness, a presence probability distribution law, as a function of the statistical parameters.

Abstract: A method for characterising nature of a material, including: providing at least one sample of the material between an X-ray source and a detector; using the X-ray source to make N X-radiation spectra transmitted through the material, each for a time; calculating transmission function of the material as a function of energy or the detection channel; and in each of at least two energy zones, calculating the integral of the transmission function, thus forming at least a first transmission coefficient and a second transmission coefficient.