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Advanced Tools for Uncertainties Visualization and Analysis in Fuel Cycle Simulations
No full textInternational audienceFuel cycle scenarios are "boundary objects" providing an opportunity to bring together different communities of stakeholders, with various knowledge and different, and sometimes opposing, interests in order to compare their visions for the future, organize their strategies and even cooperate. Uncertainties analysis is often difficult to discuss during this boundary interactions. A new method has been developed to calculate easily and represent uncertainties linked to our fuel cycle studies, representing the evolution of uncertainties with times and full distribution of outputs. The application of this method to a scenario closely inspired by the historical French fleet allows showing limited impact of uncertainties on global output like global plutonium inventory, but a significant one for inventories in specific stocks like UOX or MOX spent fuel stockpiles. Used as a support to the analysis of the impact of a new model for reactor evolution, the method confirms the significant of results from previous studies, notably those for the global plutonium inventory, the evaluation of the average value and the range of uncertainties are really similar for the two studied models. However, for the inventories in stocks, even when taken into account the large uncertainties associated, the differences appear to be significant
« New Modalities in Cancer Imaging and Therapy » XVe édition de l’atelier organisé par le réseau « Vectorisation, Imagerie, Radiothérapies » du Cancéropôle Grand-Ouest, 5–8 octobre 2022, Erquy, France
No full textNational audienceThe fifteenth edition of the international workshop organized by the "Tumour Targeting and Radiotherapies network" of the Cancéropôle Grand-Ouest focused on the latest advances in internal and external radiotherapy from different disciplinary angles: chemistry, biology, physics, and medicine. The workshop covered several deliberately diverse topics: the role of artificial intelligence, new tools for imaging and external radiotherapy, theranostic aspects, molecules and contrast agents, vectors for innovative combined therapies, and the use of alpha particles in therapy
Étude fondamentale de la solubilité du Zr(IV) et des processus de surface dans les systèmes alcalins : une étude combinée sur la solubilité, la spectroscopie et la théorie
No full textZirconium is an element of interest in the context of nuclear waste management and forms sparingly soluble ZrO2(am, hyd). The ageing or exposure to elevated temperatures expectedly results in a transition of amorphous ZrO2(am, hyd) into the thermodynamically stable crystalline phase ZrO2(cr) and thus in a decreased solubility in aqueous systems. The main objective of this study is to investigate this expected phase transformation process. Amorphous ZrO2(am, hyd) was precipitated, aged at 80°C and investigated with solid phase characterization methods (XRD, TEM, TG-DTA,…), undersaturation solubility experiments in alkaline 0.5 M NaCl-NaOH, 0.02 and 0.2 M CaCl2-Ca(OH)2 solutions and supporting theoretical calculations. The solid phase characterization results indicate, that a transformation process from amorphous towards crystalline ZrO2(s), accompanied by increasing particle size, decreasing water content and decreasing surface area is induced by ageing at 80°C. The solubility experiments show that this process also leads to a decreasing solubility, but additionally a decreasing solubility with ageing time and also for ageing at 22°C was observed and attributed to changes in the surface properties.Le zirconium est un élément intéressant dans le contexte de la gestion des déchets nucléaires et forme du ZrO2(am, hyd) peu soluble. Le vieillissement ou l'exposition à des températures élevées devrait entraîner une transition du ZrO2(am, hyd) amorphe vers la phase cristalline thermodynamiquement stable ZrO2(cr) et donc une diminution de la solubilité dans les systèmes aqueux. L'objectif principal de cette étude est d'étudier ce processus de transformation de phase attendu. Du ZrO2 amorphe (am, hyd) a été précipité, vieilli à 80°C et étudié par des méthodes de caractérisation de la phase solide (XRD, TEM, TG-DTA,…), des expériences de solubilité par sous-saturation dans des solutions alcalines de 0,5 M NaCl-NaOH, 0,02 et 0,2 M CaCl2-Ca(OH)2, ainsi que des calculs théoriques. Les résultats de la caractérisation de la phase solide indiquent qu'un processus de transformation de ZrO2(s) amorphe en ZrO2(s) cristallin, accompagné d'une augmentation de la taille des particules, d'une diminution de la teneur en eau et d'une diminution de la surface, est induit par le vieillissement à 80°C. Les expériences de solubilité montrent que ce processus conduit également à une diminution de la solubilité, mais une diminution de la solubilité avec le temps de vieillissement et également pour le vieillissement à 22°C a été observée et attribuée à des changements dans les propriétés de surface
Production de plomb-203 au GIP ARRONAX
No full textInternational audienceLes radio-isotopes de plomb-212 (t1/2 = 10,6 h) et de plomb-203 (t1/2 = 51,9 h) peuvent être utilisés pour des applications théranostiques en médecine nucléaire. Le plomb-212 est obtenu à partir de la désintégration du thorium-232 et est utilisé pour l’alphathérapie ciblée, tandis que le plomb-203 est produit par irradiation sur une cible de thallium avec des protons ou des deutérons et permet la tomographie par émission monophotonique (TEMP) grâce à son émission de photons de 279,2 keV (80,9 %). La production actuelle de plomb-203 utilise du thallium naturel bombardé par un faisceau de protons. Thallium possède deux abondances naturelles, 203 (29,5%) et 205 (70,5%). N’étant pas à 100%, la production de plomb-203 est donc limitée. Cependant, il est possible d’augmenter sa production en utilisant du thallium-205 enrichi en utilisant des tirs de deutérons. En effet, il est possible de l’enrichir jusqu’à une valeur supérieure à 99%. Afin de connaître l’estimation de la production de plomb-203, nous avons effectué des mesures de sections efficaces des différentes réactions nucléaires induites avec des deutérons sur thallium-205 enrichi. Grâce à ces expériences, nous avons défini une énergie d’irradiation optimale pour produire en grande quantité de plomb-203 tout en limitant la production de radio-impuretés principalement de plomb-201 (t1/2 = 9,33 h) et de plomb-200 (t1/2 = 21,5 h) : au GIP ARRONAX, on peut produire jusqu’à 20,7 GBq après 8h de tir à une intensité et énergie de tir respectivement de 50 µA et 32,5 MeV. En parallèle, nous avons développé une méthode de séparation chimique pour séparer thallium et plomb. Nos objectifs sont doubles : récupérer thallium-205 enrichi pour recycler et obtenir plomb-203 à haute pureté pour une utilisation clinique. Pour cela, nous avons utilisé une résine nommé résine Pb (fournisseur Triskem) et elle a permis de récupérer 80% de thallium-205 enrichi et 70% de plomb-203 à une pureté supérieure à 99% dans un milieu d’acétate d’ammonium à une concentration de 1 mol/L à pH 7.La production en grande quantité de plomb-203 est prévu à partir de septembre 2023 pour une fréquence d’une fois par mois. Les résultats de nos mesures de sections efficaces ainsi que de la séparation chimique thallium/plomb seront présentés lors de ma présentation. Une spécification de la production provisoire de plomb-203 sera également présentée
Accessing the strong interaction between baryons and charged kaons with the femtoscopy technique at the LHC
No full textInternational audienceThe interaction between baryons and kaons/antikaons is a crucial ingredient for the strangeness and sector of the meson--baryon interaction at low energies. In particular, the might help in understanding the origin of states such as the , whose nature and properties are still under debate. Experimental data on and systems are scarce, leading to large uncertainties and tension between the available theoretical predictions constrained by such data. In this Letter we present the measurements of KK and KK correlations obtained in the high-multiplicity triggered data sample in pp collisions at TeV recorded by ALICE at the LHC. The correlation function for both pairs is modeled using the LednickyLyuboshits analytical formula and the corresponding scattering parameters are extracted. The KK correlations show the presence of several structures at relative momenta above 200 MeV/, compatible with the baryon, the , and resonances decaying into K pairs. The low region in the KK also exhibits the presence of the state, expected to strongly couple to the measured pair. The presented data allow to access the K and K strong interaction with an unprecedented precision and deliver the first experimental observation of the decaying into K
Higher-order correlations between different moments of two flow amplitudes in PbPb collisions at TeV
No full textInternational audienceThe correlations between different moments of two flow amplitudes, extracted with the recently developed asymmetric cumulants, are measured in PbPb collisions at TeV recorded by the ALICE detector at the LHC. The magnitudes of the measured observables show a dependence on the different moments as well as on the collision centrality, indicating the presence of non-linear response in all even moments up to the eighth. Furthermore, the higher-order asymmetric cumulants show different signatures than the symmetric and lower-order asymmetric cumulants. Comparisons with state-of-the-art event generators using two different parameterizations obtained from Bayesian optimization show differences between data and simulations in many of the studied observables, indicating a need for further tuning of the models behind those event generators. These results provide new and independent constraints on the initial conditions and transport properties of the system created in heavy-ion collisions
A new Microscopic Model for Production in Heavy Ion Collisions
No full textInternational audienceWe present a new model for the creation of mesons in ultrarelativistic heavy ion collisions, which allows to follow the individual heavy quarks from their creation until the detector through the Quark Gluon Plasma (QGP), which is formed in these collisions and described by the EPOS2 event generator. The c and quarks interact via a potential, based on results of lattice gauge calculations. The annihilation and creation of is described by a density matrix approach whose time evolution is studied in the expanding system. The comparison with PbPb data at =5.02 TeV shows that this model can describe simultaneously the nuclear modification factor and the elliptic flow of the
Performances studies of quarkonia measurements in Run3 data at forward rapidity
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A New Model for Jet Energy Loss in Heavy Ion Collisions
No full textInternational audienceWe present a new model for jet quenching from coherent radiation in a brick medium. The jet energy loss is simulated as a perturbative final-state vacuum parton shower followed by a medium-induced shower originating from elastic and radiative collisions with the medium constituents. Coherency is achieved by starting with trial gluons that act as field dressing of the initial jet parton. These are formed according to a Gunion-Bertsch seed. The QCD version of the LPM effect is attained by increasing the phase of the trial gluons through elastic scatterings with the medium. Above a phase threshold, the trial gluons will be realised and can produce coherent radiation themselves. The model has been implemented in a Monte Carlo code and has been validated by successfully reproducing the BDMPS-Z prediction for the energy spectrum. The realistic case with minimal assumptions are also produced and shown. In particular, we show the influence of various parameters on the energy spectrum and transverse momentum distribution, such as the in-medium quark masses, the energy transfer in the recoil process, and the phase accumulation criteria, especially for low and intermediate energy gluons. Future studies will allow for the interface with full simulations of the quark-gluon-plasma with hydrodynamic evolution, such as vHLLE, along with subsequent hadronisation of the jet partons in order to produce realistic distributions that can be directly compared to LHC and RHIC data