15-12-2016 дата публикации
Номер: US20160363442A1
A method for characterizing a sample, by estimating a plurality of characteristic thicknesses, each being associated with a calibration material, including acquiring an energy spectrum (S) transmitted through this sample, located in an X and/or gamma spectral band, naled spectrum transmitted through the sample; for each spectrum of a plurality of calibration spectra (S(L; L)), calculating a likelihood from said calibration spectrum (S(L; L)), and from the spectrum transmitted through the sample (S), each calibration spectrum (S(L; L)) corresponding to the energy spectrum transmitted through a stack of gauge blocks, each formed of a known thickness of a calibration material; estimating the characteristic thicknesses (L, L) associated with the sample according to the criterion of maximum likelihood. 1. A method for characterizing a sample , by estimating a plurality of thicknesses , named characteristic thicknesses , each being associated with a material named calibration material , wherein said method comprises the following steps:{'sup': 'ech', 'acquiring an energy spectrum, named spectrum transmitted through the sample (S), said spectrum being defined by a number of photons transmitted through the sample in each channel of a plurality of energy channels located in an X and/or gamma spectral band;'}{'sup': base', 'base', 'ech', 'base, 'sub': 1', '2', '1', '2', '1', '2, 'for each spectrum of a plurality of energy spectra named calibration spectra (S(L; L)), calculating the value of a likelihood function from said calibration spectrum (S(L; L)) and from the spectrum transmitted through the sample (S), each calibration spectrum (S(L; L)) corresponding to the spectrum transmitted through a stack of gauge blocks, each gauge block being formed of a known thickness of a calibration material;'}{'sub': 1', '2, 'sup': ech', 'ech, 'determining the estimations of the characteristic thicknesses ({circumflex over (L)}; {circumflex over (L)}) associated with the sample, from said ...
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