Teses / dissertações sobre o tema "Défauts de radiation"
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Huang, Liangzhao. "Multiscale modeling of the radiation-induced segregation in Ni-based and Fe-based dilute alloys". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP048.
Texto completo da fonteWe present a quantitative modeling of the point-defect (PD) redistribution and solute radiation-induced segregation (RIS) at extended defects in dilute Ni(B ≡ Ti, Cr) and Fe(B ≡ P, Mn, Cr, Si, Ni, Cu) alloys. The change in chemical composition, in the vicinity of extended defects, plays a decisive role on the evolution of the microstructure and mechanical properties of materials. Irradiation produces PDs, that diffuse by exchanging with neighboring atoms, annihilate by mutual recombination or by interacting with extended defects (that act as PD sinks). The fluxes of PDs towards sinks lead to atomic fluxes in the same or opposite direction of the PD flux; thereby producing RIS at sinks. We extend the self-consistent mean-field theory to forced atomic relocations (FARs), athermal diffusion mechanisms generated by displacement cascades under irradiation. The implementation of the extended theory in the KineCluE code allows us to compute PD and atomic fluxes, and their couplings. From the calculation of fluxes as a function of temperature, composition, and strain field; and a mean-field treatment of the production and annihilation reactions of PDs, we obtain the steady-state RIS profiles. In each of the particular kinetic regimes for which one of the PD reactions dominates over the others, we derive analytical expressions of steady-state profiles of PDs and solute atoms at planar sinks. To account for the effect of strain generated by an edge dislocation on the RIS and PD elimination rates, we numerically solve the elastodiffusion equations. Based on an ab initio database of binding energies, elastic dipoles, and atom-PD exchange frequencies, we perform a systematic study of the effects of the microstructure and irradiation conditions on diffusion properties, PD elimination rates at sinks, and RIS. We show that: (i) the dislocation loops are enriched in Ni in Fe(Ni) and depleted in Ti in Ni(Ti), and the calculated amounts of RIS are in good agreement with the experimental values measured in model Fe(Ni) and Ni(Ti) alloys irradiated by ions; (ii) at high flux, low temperature, and high sink strength, forced atomic relocations significantly reduce RIS, especially in Ni-based alloys; (iii) the temperature shifts calculated to simulate the effects of neutron irradiation by ion irradiation can be very different depending on the radiation-induced phenomenon, the kinetic regime in which the system evolves, and the chemical nature of the investigated alloy; (iv) the interactions between PDs and solute atoms change the absorption bias between vacancies and interstitials of an edge dislocation, as for instance, the addition of Ni leads to a negative bias while the addition of Mn increases the bias factor (up to 200% of the strained pure Fe value), depending on temperature and composition; (v) the dislocation strain field significantly increases Ni RIS (e.g., about 400% of the strain-free value at 400K) in Fe(Ni), and changes the sign of RIS in Fe(Cr)
Gérardin, Marie. "Etude du comportement thermique des gaz de fission dans l'UO₂ en présence de défauts d'irradiation". Thesis, Orléans, 2018. http://www.theses.fr/2018ORLE2051/document.
Texto completo da fonteDuring in-reactor irradiation, fission gases such as xenon or krypton are produced. In the fuel, those gases diffuse and precipitate to form bubbles. In addition, fission reactions induce small defects(vacancies and interstitials) and larger defects (cavities and dislocations) formation. Data acquire menton fission gases migration considering radiation-induced defects is thus necessary to better understand and improve models of in-pile fuel behavior. The experimental approach developed in this work aims to study thermal diffusion of rare gases and to understand their interaction with radiation-induced defects.To do this, separated effect studies were performed coupling ion implantations/irradiations to fine characterization techniques. Positron Annihilation Spectroscopy (PAS) coupled to Transmission Electron Microscopy (TEM) observations allows for defects characterizations (vacancies and/or cavities induced by ion implantation) and for their thermal behavior study. On the other hand, gas release measurements are performed by thermal desorption spectrometry. Simulation of gas kinetic release allows to determine diffusion coefficients and to lighten trapping mechanisms. The synthesis of those various experimental results brings us to identify gas migration mechanism and to describe their interaction with radiation-induced defects
Arnolda, Pierre. "Lacréation de défauts de déplacements atomiques dans le silicium et son impact sur les composants électroniques à applications spatiales". Toulouse, ISAE, 2011. http://www.theses.fr/2011ESAE0016.
Texto completo da fonteGoutaland, François. "Processus multiphotoniques, défauts ponctuels et mécanismes de leur formation dans les fibres optiques : étude par spectroscopie laser". Saint-Etienne, 1998. http://www.theses.fr/1998STET4021.
Texto completo da fonteJin, Xin. "Combining RBS/Channeling, X-ray diffraction and atomic-scale modelling to study irradiation-induced defects and microstructural changes". Thesis, Limoges, 2021. http://www.theses.fr/2021LIMO0017.
Texto completo da fonteEnergetic particles are involved in many activities of modern society. They constitute a significant aspect of the semiconductor industry and may play important role in shaping materials in a controllable way in the future. However, their energetic nature also poses grand challenges, especially in the nuclear industry. Thus, it is crucial to have a comprehensive understanding of the underlying mechanisms of irradiation-induced defects and the associated microstructural changes. Experimentally, irradiation-induced effects can be monitored by characterization techniques including, but not limited to, Rutherford backscattering spectrometry in channeling mode (RBS/C) and X-ray diffraction (XRD), because they are extremely sensitive to changes in the crystalline structure. However, it is not straightforward to establish a clear link between the characterization results and the defect quantity and nature, and this connection is usually made according to simple phenomenological models. In this thesis work, in order to cope with this problem, we performed RBS/C and XRD atomic-scale modelling. The first step was to improve a recently developed RBS/C simulation code that can generate RBS/C signals from arbitrary atomic structures. By modifying the algorithms describing ion-solid interactions and adding new features, we enhanced the flexibility of the code and its applicability to different types of materials. Subsequently, we employed the improved RBS/C code with a XRD program to compute disordering and elastic strain kinetics of a model material, namely UO2, as a function of irradiation fluence. Radiation defects in UO2 were simulated by molecular dynamics (MD) calculations. Both the strain and disordering kinetics exhibit qualitatively close agreement with those determined experimentally, indicating the validity of the used methodology. The decomposition of the kinetics was performed in order to study the effect of each defect separately, which enables a quantitative description of the disordering and strain build-up processes. Finally, we computed RBS/C and XRD signals from Fe MD cells, each of which contains one single type of defects. A clear comparison of disorder and elastic strain induced by different types of defects in Fe was made. The relation between RBS/C yield and He energy was also studied using the Fe MD cells, which shows dependency with defect types. The global approach used in this work has the hope to be extended and tested in more materials
Piochaud, Jean-Baptiste. "Modelling of radiation induced segregation in austenitic Fe alloys at the atomistic level". Electronic Thesis or Diss., Lille 1, 2013. http://www.theses.fr/2013LIL10024.
Texto completo da fonteIn pressurized water reactors, under irradiation internal structures are subject of irradiation assisted stress corrosion cracking which is influenced by radiation induced segregation (RIS). In this work RIS of 316 stainless steels is modelled considering a model ternary Fe–10Ni–20Cr alloy. For this purpose we have built an Fe-Ni-Cr pair interaction model to simulate RIS at the atomistic level using an atomistic kinetic Monte Carlo approach. The pair interactions have been deduced from density functional theory (DFT) data available in the pure fcc systems but also from DFT calculations we have performed in the Fe–10Ni–20Cr target alloy. Point defect formation energies were calculated and found to depend strongly on the local environment of the defect. As a consequence, a rather good estimation of these energies can be obtained from the knowledge of the number and respective positions of the Ni and Cr atoms in the vicinity of the defect. This work shows that a model based only on interaction parameters between elements positioned in perfect lattice sites (solute atoms and vacancy) cannot capture alone both the thermodynamic and the kinetic aspect of RIS. A more accurate of estimating the barriers encountered by the diffusing species is required than the one used in our model, which has to depend on the saddle point environment. This study therefore shows thus the need to estimate point defect migration energies using the DFT approach to calibrate a model that can be used in the framework of atomic kinetic Monte Carlo simulations. We also found that the reproduction by our pair interaction model of DFT data for the self-interstitial atoms was found to be incompatible with the modelling of RIS under electron irradiation
Tortech, Blandine. "Effets des radiations sur des fibres optiques dopées erbium : influence de la composition". Phd thesis, Université Jean Monnet - Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00366057.
Texto completo da fontePiochaud, Jean-Baptiste. "Modelling of radiation induced segregation in austenitic Fe alloys at the atomistic level". Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10024/document.
Texto completo da fonteIn pressurized water reactors, under irradiation internal structures are subject of irradiation assisted stress corrosion cracking which is influenced by radiation induced segregation (RIS). In this work RIS of 316 stainless steels is modelled considering a model ternary Fe–10Ni–20Cr alloy. For this purpose we have built an Fe-Ni-Cr pair interaction model to simulate RIS at the atomistic level using an atomistic kinetic Monte Carlo approach. The pair interactions have been deduced from density functional theory (DFT) data available in the pure fcc systems but also from DFT calculations we have performed in the Fe–10Ni–20Cr target alloy. Point defect formation energies were calculated and found to depend strongly on the local environment of the defect. As a consequence, a rather good estimation of these energies can be obtained from the knowledge of the number and respective positions of the Ni and Cr atoms in the vicinity of the defect. This work shows that a model based only on interaction parameters between elements positioned in perfect lattice sites (solute atoms and vacancy) cannot capture alone both the thermodynamic and the kinetic aspect of RIS. A more accurate of estimating the barriers encountered by the diffusing species is required than the one used in our model, which has to depend on the saddle point environment. This study therefore shows thus the need to estimate point defect migration energies using the DFT approach to calibrate a model that can be used in the framework of atomic kinetic Monte Carlo simulations. We also found that the reproduction by our pair interaction model of DFT data for the self-interstitial atoms was found to be incompatible with the modelling of RIS under electron irradiation
Kaddissy, Josiane. "Hydrogen production from irradiated aluminum hydroxide and oxyhydroxide". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS253/document.
Texto completo da fonteDihydrogen production is a critical issue for the current management of nuclear wastes. One potential source of hydrogen generation is the radiolysis of hydrated mineral phases encountered in the nuclear waste transportation and storage casks. We chose to study aluminum hydroxide (Al(OH)3) (Bayerite) and oxyhydroxides (AlOOH) (Boehmite) as model compounds. The determination of molecular hydrogen production was evaluated with respect to structure and particle size at room temperature and after annealing. In order to have a better understanding of the mechanisms and to identify the precursors of molecular hydrogen, we studied the irradiation defects and their stabilities using Electron Paramagnetic Resonance (EPR). The effect of adsorbed water and structural water on the molecular hydrogen production was studied. Different radiation sources were used such as Gamma radiation, electron beam radiations and heavy ions. In the last part, preliminary results related to the impact of impurities on hydrogen production are presented
Hongisto, Mikko. "Développement de verres et vitrocéramiques dopés ytterbium pour l'optique et réponses sous différents types de traitements". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0040.
Texto completo da fonteThis thesis studies the modification of the properties of glass compounds doped with Yb3+ ions, through variations in composition, thermal or radiation treatments as well as by immersion in aqueous medium. New Yb3+ doped oxyfluorophosphate glass/glass-ceramics have been developed and characterized to obtain fundamental information on crystallization. The study also proposes the development of cylindrical and rectangular bioactive fibers based on doped and non-doped borosilicate glass constituting the core and the clad of the fiber respectively. The stability of these fibers in aqueous medium is monitored according to the geometry. This study also provides information on resistance to defects depending on the nature of the network and on the development of new bioactive fibers, the emission of which could be used to follow the dissolution of the fiber in aqueous medium. This study contributes to a better fundamental understanding of how composition changes and thermal/radiation processes can modulate the performance parameters of glass materials doped by Yb3+ ions
Krautwurm, Jiri. "Préparation, caractérisation physico-chimique et étude des défauts paramagnétiques des oxynitrures de silicium à faible taux d'hydrogène". Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10072.
Texto completo da fonteMancini, Lucia. "Étude des défauts dans les quasicristaux en utilisant les aspects nouveaux de l'imagerie aux rayons X associés aux sources synchrotron de troisième génération". Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10077.
Texto completo da fonteYin, Chengying. "Hydrogen production from irradiated calcium silicate hydrate". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS355/document.
Texto completo da fonteIn France, cementitious materials are used as conditioning matrix of low level and intermediate level nuclear wastes. Water radiolysis occurs due to the nuclear wastes stored in the materials. The formation of its radiolytic products such as H₂ gas must be evaluated for safety reasons. Calcium silicate hydrate (C-S-H) is the main product (50%) of hydration of Portland Cement (PC). The aim of this study is to understand the radiolytic mechanisms of the hydrogen production in C-S-H, to investigate the effect of impurities (such as alkali ions, additional hydroxides or nitrates ions) on H₂ gas production in C-S-H and to examine if interactions exist between different main phases (C-S-H and portlandite) in cement matrix. After using various characterization techniques, samples were submitted to different types of irradiation (gamma rays and electrons and heavy ions (HI) beams) to determine their H₂ radiolytic yield, G(H₂). In C-S-H system, it has been shown, under gamma irradiation, that G(H₂) does not depend on water content, moreover, C-S-H system itself produce efficiently H₂ gas. The comparison between the results obtained under gamma rays and that obtained under HI implies: there is no/ low LET effect in C-S-H. While with nitrate ions in C-S-H, a large decrease of G(H₂) is observed. Irradiation of C2S and C3S hydrates mainly composed of C-S-H and portlandite shows that here is no energy transfer phenomena between these two phases. Finally, the electron paramagnetic resonance (EPR) spectroscopy experiments have enabled proposing radiolytic mechanisms. All these results help us to understand the radiation effects in cements
Naceur, Mehdi. "Impact des ions lourds sur la fiabilité des MOSFET de puissance embarqués en environnement spatial". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20180/document.
Texto completo da fonteThe goal of this thesis is oriented mainly on the study of Post Irradiation Gate Stress (PiGS) of power MOSFETs irradiated with heavy ions. We have seen, for the first time, a reduction of reliability parameters and lifetime of power MOSFETs irradiated with heavy ions using a test panel combining the knowledge of the effects of radiation and accelerated electrical test. MOSFETs were irradiated mainly with no polarization, in order to discriminate any effect attributed to the polarizations. Using irradiation performed at different energy values, we investigated the effects of the energy and energy lost by ionizing and non ionizing process. We have seen that the reliability degradation of MOSFETs can't be correlated only to the energy lost by electron excitation (LET), or ions with the same LET value obtained for two different energies, the worst case was observed at the lowest energy. This degradation is even greater than that obtained with the maximum value of LET (the Bragg peak). Supported by results obtained by neutrons irradiation, we could propose a hypothesis that is based on a correlation between the effect of energy lost associated with the passage of ions and mechanisms of dielectric breakdown
Belloir, Jean-Marc. "Spectroscopie du courant d’obscurité induit par les effets de déplacement atomique des radiations spatiales et nucléaires dans les capteurs d’images CMOS à photodiode pincée". Thesis, Toulouse, ISAE, 2016. http://www.theses.fr/2016ESAE0029/document.
Texto completo da fonteCMOS image sensors are envisioned for an increasing number of high-end scientific imaging applications such asspace imaging or nuclear experiments. Indeed, the performance of high-end CMOS image sensors has dramaticallyincreased in the past years thanks to the unceasing improvements of microelectronics, and these image sensors havesubstantial advantages over CCDs which make them great candidates to replace CCDs in future space missions.However, in space and nuclear environments, CMOS image sensors must face harsh radiation which can rapidlydegrade their electro-optical performances. In particular, the protons, electrons and ions travelling in space or thefusion neutrons from nuclear experiments can displace silicon atoms in the pixels and break the crystalline structure.These displacement damage effects lead to the formation of stable defects and to the introduction of states in theforbidden bandgap of silicon, which can allow the thermal generation of electron-hole pairs. Consequently, nonionizingradiation leads to a permanent increase of the dark current of the pixels and thus a decrease of the imagesensor sensibility and dynamic range. The aim of the present work is to extend the understanding of the effect ofdisplacement damage on the dark current increase of CMOS image sensors. In particular, this work focuses on theshape of the dark current distribution depending on the particle type, energy and fluence but also on the imagesensor physical parameters. Thanks to the many conditions tested, an empirical model for the prediction of the darkcurrent distribution induced by displacement damage in nuclear or space environments is experimentally validatedand physically justified. Another central part of this work consists in using the dark current spectroscopy techniquefor the first time on irradiated CMOS image sensors to detect and characterize radiation-induced silicon bulk defects.Many types of defects are detected and two of them are identified, proving the applicability of this technique to studythe nature of silicon bulk defects using image sensors. In summary, this work advances the understanding of thenature of the radiation-induced defects responsible for the dark current increase in space or nuclear environments. Italso leads the way to the design of more advanced dark current prediction models, or to the development ofmitigation strategies in order to prevent the formation of the responsible defects or to allow their removal
Goguenheim, Didier. "Étude théorique et expérimentale de la capture non-radiative de porteurs libres dans les semi-conducteurs : application à la liaison pendante de silicium à l'interface Si/SiO2 (Centre Pb)". Lille 1, 1992. http://www.theses.fr/1992LIL10046.
Texto completo da fonteSibille, Alain. "Etude des défauts créés par irradiation électronique dans InP". Paris 7, 1985. http://www.theses.fr/1985PA077083.
Texto completo da fonteBisutti, Jean. "Etude de la transmission du signal sous irradiation transitoire dans les fibres optiques". Thesis, Saint-Etienne, 2010. http://www.theses.fr/2010STET4011.
Texto completo da fonteThis PhD thesis presents a study about the response of optical fibers to a transient irradiation (X-ray pulse, ~1 MeV, doses < 100 krad, dose rates > 108 rad s-1). Additional measurements under steady-state gamma-ray have also been performed (~1,2 MeV,doses ≤20 krad, dose rates ~0,5 rad s-1). Our study falls within the more general framework of the integration of optical fibers into the Laser Megajoule facility. The first chapter describes this framework together with the radiation induced defects in pure ordoped silica. The second chapter is focus on the experimental set-up used to measure the induced attenuation. We also give a sum up of the obtained measurements with pure-silica-core fibers and with fibers doped with germanium and/or phosphorus. The third chapter is dedicated to the analysis of the induced losses. The experimental spectra of radiation-induced attenuation have been decomposed with absorption bands related to absorbing defects generated. We have used an original method of decomposition based on the use of absorption bands previously identified in literature. Some physical mechanisms of defect generation and defect transformation have been suggested
Wane, Sada Taminou. "Systématique de la photoionisation et de la recombinaison radiative dans les séquences isoélectroniques du potassium, du rubidium, du cuivre et de l'argent". Paris 11, 1988. http://www.theses.fr/1988PA112007.
Texto completo da fonteIn the framework of a non-relativistic single electron model, photoionisation cross sections from ground and excited n. T states have been computed for the K, Rb, Cu and Ag isoelectronic sequences, by the use of a parametric central potential. The evolution of the non-hydrogenic behaviour of photoionisation cross sections near threshold is studied along Rydberg series and along the isoelectronic sequences, and emphasis is put on the occurrence of minima and maxima in the photoïonisation cross section curves. Systematic trends along an isoelectronic sequence and in addition along the sequence of neutral alkali atoms Li through Cs, and the comparison of the behaviour along the different K, Rb, Cu and Ag isoelectronic sequences are analysed in terms of the quantum defect theory. Through the principle of the detailed balance radiative recombination rate coefficients have been obtained along the isoelectronic sequences, rather for relatively low temperatures. Markedly and peculiar non-hydrogenic features are outlined and the systematics of recombination along the isoelectronic sequences are analysed. Comparisons for bath photoïonisation and recombination results are made with mainly those of the hydrogenic model, and with other available theoretical or experimental results
Artola, Laurent. "Étude et modélisation des mécanismes de transport et de collection de charges dédiées à la prédiction de SEE dans les technologies fortement intégrées". Toulouse, ISAE, 2011. http://www.theses.fr/2011ESAE0025.
Texto completo da fonteNatural radiative environment is known to induce functional errors in electronics. Particles, such as neutrons, protons or heavy ions are known to induce these errors in electronic devices so called SEE (Single Event Effects). It's critical for industrial and space agencies to evaluate this risk. In this context, a new methodology of prediction is proposed in order to stimate the operational error rate for integrated devices boarded in space or avionic flights. Preliminary TCAD simulations lead to identify the physical mechanisms of transport and charges collection and lead to determine the critical technological parameters which impact the behaviour of the MOS transistor. These works emphasize the necessity to take into account the dynamic modeling of ambipolar diffusion velocity. Based on these works, the ADDICT model (Advanced Dynamic Diffusion Collection Transient) has been proposed. The main part of this work is focus on the validation of the transient current model by comparisons with experimental results ans TCAD simulations. In order to study the SEU and MBU events, a new upset criterion used with ADDICT leads to propose a new prediction methodology. This methodology has been compared with experimental cross sections issued from literature and tests campaign (for various SRAM memories from 0. 25 µm to 65 nm). Finally the ADDICT model has been evaluated for operational experiments. Actually, commercial SRAM memories (90 nm Cypress) has been boarded on stratospheric balloons. This last work shows the relevant operational prediction proposed by ADDICT
Le, Roch Alexandre. "Analyse de l’augmentation et de la fluctuation discrète du courant d’obscurité des imageurs CMOS dans les environnements radiatifs spatiaux et nucléaires". Thesis, Toulouse, ISAE, 2020. http://www.theses.fr/2020ESAE0018.
Texto completo da fonteInspired by the microelectronic Complementary Metal Oxide Semiconductor (CMOS) technologies, CMOS image sensors are widely used in many consumer-grade applications and are predominant in the commercial market for embedded cameras. Over the past decade,numerous technological advances allowed state-of-the-art CMOS image sensors to achieve excellent performances as well as low-power consumption. Therefore, CMOS image sensors are becoming essential candidates for a growing number of high-end applications such as space and nuclear applications. However, the behavior of these microelectronic devices inspace and nuclear radiative environments is still under understanding. Hence, studies still investigate the different mechanisms that lead to the degradation of CMOS image sensor performances including the radiation-induced dark current increase, a parasitic signal that increases with radiation doses. Among these radiation doses, the so-called displacement dose,relative to the alteration of the crystalline structure of the silicon, remains poorly studied compared to the so-called ionizing dose. In the latest CMOS image sensor technologies using pinned photodiodes, the ionizing dose is no longer the main degradation mechanism when the displacement dose is at stake. From then on, the displacement dose becomes the principal degradation mechanism that leads to the dark current increase. This work mainly focuses onthe role of the crystalline defects, created by radiation-induced displacement damage, in the CMOS image sensor dark current increase. Particular interest is given to metastable defects,which are probably the cause of discrete and random fluctuations of the dark current called : Dark Current Random Telegraph Signal (DC-RTS). This study presents a double objective :The first aims to contribute to improving knowledge of the physical principles involved in crystalline silicon when facing radiations. Particle-matter interactions, combined with the specific architecture of image sensors, aim to provide reliable tools to analyze the radiation induced defects in silicon. Observations and findings can be extended to all silicon-based devices and more generally to other semiconductor-based devices.The second seeks to identify the different mechanisms leading to CMOS image sensor dark current increase when operating in radiative environments. The study aims to identify and improve knowledge on the behavior of dark current sources aiming to optimize CMOS image sensors for future space and nuclear applications
Rouland, Solene. "Etude expérimentale des cinétiques de diffusion et de la ségrégation induite sous irradiation d'alliages modèles et industriel austénitiques". Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR050.
Texto completo da fonteRadiation induced segregation (RIS) is a process identified to be involved in most of the degradation mechanisms of austenitic stainless steels core components of nuclear reactors. During irradiation within the operating temperature range of present and possible prototypes of future reactors, chemical elements of reactor internal metallic components redistribute heterogeneously and segregate on the pre-existent and newly created defects. Local enrichments or depletions levels depend, inter alia, on the element and nature of the defect affected. While mechanisms involved in RIS have already been identified, their kinetics and mutual weigh are still poorly known. Indeed, current theorical models of RIS suffer from a lack of experimental data. These two aspects motivated this study. First, by the determination of interdiffusion kinetics after thermal ageing and under irradiation on model alloys in the Fe-Ni-Cr system. Irradiation effect on diffusion have been studied at 440°C. At this temperature, conventional methods to study diffusion fail to give access to such slow kinetics under reasonable time. Experimental implementation of the nanolayers method on binary and ternary alloys gave, in this case, encouraging results. However, discrepancies between experiments and predictions revealed the need of optimizations on both sides. In the framework of this study, recommendations have been established to account for the effect of the microstructure and the selected ageing conditions on measured effective kinetics. Experiments on model alloys have the great interest to be directly confronted to simulation. Nevertheless, nuclear steels contain a large variety of minor alloying elements and impurities which have shown to play a key role on RIS behaviour. Thus, in a second part, RIS study on various bulk defects of an optimized nuclear austenitic stainless steel, a 316L(N) has been performed. Consequently, nanoscale coupled and correlated techniques (Atom Probe Tomography and Transmission Eelectron Microscopy) have been implemented. Techniques complementarity offered the possibility to associate enrichments to defect crystallography and revealed singular tendencies of RIS depending on the element and the defect involved. Furthermore, a higher nitrogen and niobium content in the steel nominal composition formed primary Z-phase, its stability under irradiation had also been for the first time studied in austenitic stainless steels