Добірка наукової літератури з теми "Pile-up (empilements)"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Pile-up (empilements)".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Дисертації з теми "Pile-up (empilements)":
Potop, Alexandra-Iulia. "Imagerie par rayons X résolue en énergie : Méthodes de décomposition en base de matériaux adaptées à des détecteurs spectrométriques." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0096/document.
Scintillator based integrating detectors are used in conventional X-ray imaging systems. The new generation of energy-resolved semiconductor radiation detectors, based on CdTe/CdZnTe, allows counting the number of photons incident on the detector and measure their energy. The LDET laboratory developed pixelated spectrometric detectors for X-ray imaging, associated with a fast readout circuit, which allows working with high fluxes and while maintaining a good energy resolution. With this thesis, we bring our contribution to data processing acquired in radiographic and tomographic modes for material components quantification. Osteodensitometry was chosen as a medical application. Radiographic data was acquired by simulation with a detector which presents imperfections as charge sharing and pile-up. The methods chosen for data processing are based on a material decomposition approach. Basis material decomposition models the linear attenuation coefficient of a material as a linear combination of the attenuations of two basis materials based on the energy related information acquired in each energy bin. Two approaches based on a calibration step were adapted for our application. The first is the polynomial approach used for standard dual energy acquisitions, which was applied for two and three energies acquired with the energy-resolved detector. We searched the optimal configuration of bins. We evaluated the limits of the polynomial approach with a study on the number of channels. To go further and take benefit of the elevated number of bins acquired with the detectors developed in our laboratory, a statistical approach implemented in our laboratory was adapted for the material decomposition method for quantifying mineral content in bone. The two approaches were compared using figures of merit as bias and noise over the lengths of the materials traversed by X-rays. An experimental radiographic validation of the two approaches was done in our laboratory with a spectrometric detector. Results in material quantification reflect an agreement with the simulations
Montagu, Thierry. "Transformées stabilisatrices de variance pour l'estimation de l'intensité du Shot Noise : application à l'estimation du flux neutronique." Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5015.
The Shot noise is a random process that can be used to accurately model the numberof occurrences of physical particles impinging their associated detectors ; this numberis referred to as the intensity of the process. When this number is small, it is possible to individualize the recorded events whose arrival times are modelled thanks to the Poisson process. In the opposite case, the events are no longer discernible (they ”pile up”), but Campbell's theorem - which establishes the cumulants of the Shot Noise - still allows to estimate the intensity of the process. The estimation of the two first cumulants is classically achevied with the empirical mean and the empirical variance. It is noted in this work, that the variances of theses two estimators and their corresponding estimators of the Shot Noise intensity are functions of their respective means. This property ofheter heteroscedasticity being observed both in theory and practice, an approach by variance stabilizing transforms is proposed using the "Delta method". These are calculated as well as their bias, and their corresponding inverse transforms. Their asymptotic properties are verified thanks to numerical simulations. In the applicative context of neutron flux measurements, which rely on the estimation of the first two cumulants of the Shot Noise and which also have the purpose of estimating the intensity of this random process,variance stabilizing transforms are specifically established as well as their biases and their inverse transforms. They are finally combined with an adaptive Kalman filter in order to denoise the neutron flux measurements. Numerical simulations are carried out to assessfiltering performances. Denoising of real signals is also performed
Chen, Xiaolei. "Experimental and theoretical studies of incompatibility and dislocation pile-up stresses at grain boundaries accounting for elastic and plastic anisotropies." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0089.
The mechanical properties of metallic materials strongly depend on the dislocation behavior, such as the density, the distribution, the nucleation and the mobility of dislocations as well as the interactions between dislocations and grain boundaries (GB). The main objective of this thesis is to study the effects of elastic and plastic anisotropies on the dislocation-GB interaction considering complex properties of GBs, misorientation effects and free surfaces effects. To reach this objective, an analytical approach based on the L-E-S formalism was investigated, which provides the elastic fields of single straight dislocations and different dislocation pile-ups at GBs in anisotropic homogeneous media, half-spaces, bi- and tri-materials while possibly considering free surface effects. The tri-material configuration allows considering a non-zero thickness in the nanometer range and a specific stiffness tensor for the GB region. The configuration with two free surfaces was used to study size effects. The effects of anisotropic elasticity, crystallographic orientation, GB stiffness and free surfaces were studied in the case of a single dislocation and dislocation pile-ups in a Ni bi-crystals with image forces and pile-ups length analyses, respectively. In parallel, in-situ compression tests on micron-sized Ni and α-Brass bi-crystals produced from FIB machining and observations coupling SEM, AFM and EBSD were performed. The compression test was performed with a low strain. Then, step height spatial variations due to localized slip bands terminating at GB were measured by AFM to determine the Burgers vector distribution in the dislocation pile-up. This distribution was then simulated by dislocation pile-up configuration in bi-crystals with the experimentally measured parameters by considering the effect of misorientation, GB stiffness, free surfaces, incompatibility stresses and critical force. In particular, the incompatibility stresses were analyzed using CPFEM simulations and the thickness of GB was simulated using atomistic simulations with LAMMPS
Aouadi, Mehdi. "Détermination du rapport d’embranchement de la transition super-permise du carbone 10 et développement et intégration de la ligne de faisceau PIPERADE au CENBG." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0926/document.
The beta radioactivity studies in nuclear medium allow to participate in thedetermination of one of the parameters that describes the weak interaction (the vectorcoupling constant). For this purpose, numerous measurements have already been made todetermine this parameter with great precision for superallowed transition nuclei. However,for carbon 10, the relative uncertainty of the branching ratio is still high compared to otherparent nuclei with a value of the order of 0.13%. This high uncertainty is due to photonenergy emitted of 1021.6 keV which is really closed to the energy due to pile-up of twophotons of 511 keV. In May 2015, our group conducted an experiment at ISOLDE at CERN tomeasure the branching ratio very precisely. The nuclear reactions needed to produce thenuclei gave a large amount of nuclei of interest but also contaminants of the same massewhich also emit beta+ particles. A pile-up ratio of around 0.1 μs was calculated. Then, wefound a branching ratio of 1.500(4) % whereas the average from litterature is 1.4645(19) %.To study more species of nuclei and increase the intensity of the beams, GANIL(Grand Accélérateur National d’Ions Lourds) is currently developing a new accelerator as wellas a set of targets based on ISOL method. In order to reduce the contaminants deposit atthe measurement points, as we saw for the measurement of carbon 10 at ISOLDE, thecommunity of physicists also wants to develop separation apparati. In this context, since2011, our group has been involved in the development of two of these tools: a highresolutionseparator (HRS) to separate nuclei which need a mass resolving power (m / Δm)around 20,000 and a double Penning trap (PIPERADE) to separate the nuclei which require amaximum resolution of 100,000. Thus, at CENBG, a test beam line that includes a FEBIAD ionsource, a RFQ cooler-buncher (GPIB), an electrostatic switch, and a double Penning trap(PIPERADE) is under development. During apparati tests, we observe a transmissionefficiency around 80 %. Also, we measure a transverse emittance about 3 pi.mm.mrad whichis lower than 26 pi.mm.mrad observed before the GPIB. By the way, simulations of the beamline permitted to decelerate the beam and inject 98 % of ions.This thesis consists of two parts: the determination of the carbon 10 branching ratioand the development and integration of the PIPERADE beam line at CENBG
Camacho, Toro Reina Coromoto. "Recherche de nouvelles résonances se désintégrant en paires de quarks top avec le détecteur ATLAS du LHC." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00818796.