Hydrogen permeation in metals
In the context of developing the hydrogen sector, understanding the interactions between hydrogen and materials is a key challenge.
When hydrogen comes into contact with metallic materials, it can dissolve into the matrix and diffuse through it—a phenomenon known as permeation.
Hydrogen permeation measurements in metals have been developed at the CEA-Grenoble for over 20 years.
The objective of this post-doctoral project is to investigate these permeation phenomena when hydrogen is introduced at high pressure and when pollutants are present in the hydrogen.
The project will begin with the design and implementation of a new permeation test bench, which must enable high-pressure testing and precise control of impurity levels in the hydrogen.
Subsequently, the study will focus on the effect of pressure and impurities on hydrogen permeation in ferrito-pearlitic steels, using the previously developed test bench.
Design and implementation of an alternative to representation predicates in Frama-C
Frama-C is a collaborative platform for analysis of C programs. Among the different tools available in Frama-C, WP is dedicated to deductive verification of programs, allowing mathematical proof of functional properties and absence of runtime errors. This tool is used for years in industry.
Separation logic is the most promising way to allow verification of properties for programs involving complex data structures. However, it is hard to use for industrial use-cases. The main reason for this is that it is hard to encode into automatic proof tools. Thus, its use requires a lot of work from users.
In a recent work, we described how to extend WP tooling tout describe the memory footprint of C data-structures. The idea is to provide a specification language that allows to capture most of the power of separation logic without having to encode it in proof tools. The goal of this postdoc is to experiment the use of this formalism to describe real world use cases and implement its support in Frama-C and WP.
Global Power System Modeling under Planetary and Social Boundaries
The EQUALS project (EQUitable Allocation of Low-carbon Electricity Sources in a Changing and Resource-limited World) addresses the challenge of transitioning from fossil fuels to low-carbon energy under the constraint of planetary and social boundaries. While the rapid electrification of end-uses is a major lever against climate change, the transition faces limited natural resources, carbon budgets, and territorial specificities. EQUALS assesses the feasibility of meeting global energy needs within these limits, treating energy as a common.
Based at CEA Liten in Grenoble, this 18-month postdoctoral position establishes the project’s methodological foundations. The mission focuses on the generation of country-level hourly electricity demand time-series. This work involves reconstructing demand profiles that integrate thermal sensitivity (heating and cooling), socioeconomic development trajectories, and the electrification of end-uses. In parallel, vRES (variable Renewable Energy Sources) generation profiles will be developed to quantify resource availability worldwide.
These data will feed a global optimization model to identify transition pathways that minimize reliance on fossil fuels, while respecting social floors and planetary ceilings. The candidate will join the interdisciplinary EQUALS team, collaborating with a network of experts in modeling, energy geography, industrial ecology, and climate science. This position offers a stimulating research environment within the Grenoble scientific ecosystem, bridging technical engineering with sustainability science.
Thermal properties of 3D aluminum nitride structures for electronic packaging
The 12-month postdoctoral fellowship is part of the overall 3DNAMIC project, funded by the Occitanie region and involving the Materials platform of the DRTDOCC department and the Laplace laboratory. A thesis began in December 2024 aimed at “the study and characterization of 3D aluminum nitride ceramics for the thermal packaging and management of electronic components.”
The postdoc is scheduled to begin at approximately in September 2026, with the following main objectives:
Objective 1: Perform a comparative analysis of the thermal properties of ceramics produced by AF elements and on model structures using different materials available in the CEA materials platform.
Objective 3: Propose, qualify, and validate, numerically and then experimentally, heat dissipation structures for ceramics obtained by FA as part of the 3DNAMIC project.
Integrating dynamic CRDTs replicas
Existing modeling frameworks have limited collaboration capabilities. Collaboration at the model level is one of the top desired features. However, most solutions rely on cloud-based and centralized databases as their technological solution. While these solutions ease collaboration among connected partners by employing concurrency control techniques, they do not support disconnected collaboration scenarios, which is an important feature for designing local-first software. This situation presents a significant compromise: utilizing cloud-based solutions with loss of data ownership control versus adopting separate instances without collaborative capabilities.
The objective of this postdoctoral project is to contribute to and extend an existing local-first Model-Based Systems Engineering (MBSE) framework, built upon specialized Conflict-free Replicated Data Types (CRDTs). The goal is to enable real-time collaboration through modeling-specific CRDTs. The proposed approach involves extending a middleware communication layer utilizing CRDTs to
seamlessly synchronize distributed, offline-capable engineering models.
The postdoctoral researcher will conduct a state-of-the-art review of communication and group membership approaches in P2P environments. One major issue to be taken into account is the entry and exit of members in a group, so the CRDT state is always
coherent. The components will be integrated into our CRDT and modeling framework.
A posteriori estimates for the mixed finite element discretization of the multigroup diffusion criticality problem
A postdoctoral fellowship is proposed on the a posteriori estimates for the mixed finite element discretization of the multigroup diffusion criticality problem.
The objective is to develop efficient and reliable a posteriori estimates for a multigroup diffusion criticality problem with strong spatial heterogeneities, i.e. a model where the parameters, typically the coefficients of the equations, vary rapidly in space. Mathemically speaking, the criticality problem is a non-symmetric generalized eigenvalue problem.
At the reactor core scale, using simplified models is common in the nuclear industry. Precisely, the simplified models can be the neutron diffusion model or the simplified transport model. We derived rigorous em a posteriori error estimates for mixed finite
element discretizations of the neutron diffusion source problem, and proposed an adaptive mesh refinement strategy that preserves the Cartesian structure. A first application of this approach to the criticality problem was performed. Regarding the industrial context and specifically the numerical simulations, our approach is part of the development of a mixed finite element solver called MINOS in the APOLLO3 code. Further extensions of the a posteriori estimates were studied such the multigroup diffusion source problem and a Domain Decomposition decomposition denoted the DD+L2 jumps method. The enlisted approaches are based on the formulation of a source problem. The objective is to extend the a posteriori approach to a non-symmetric generalized eigenvalue problem.
Study of a low-cost K-ion storage system: electrolyte, safety and prototyping
The UPBEAT project (France 2030) aims to develop a low-cost potassium-ion technology that is free of critical materials and capable of providing the performance of LiFePO4-type Li-ion cells. The work proposed to the post-doc is in line with this objective: it will involve developing optimised organic liquid electrolytes for this new system (Prussian White vs. Graphite), by studying the most promising salts, solvents and additives, while maintaining the objectives of cost and durability. The proposed solutions (with and without fluorine) will be formulated, characterised and electrochemically tested in complete cells (coin cells and pouch cells including components optimisations) to measure their effectiveness in terms of lifetime and power response. Operando measurements and post-mortem characterisations will be used to understand the effects of the various components. The systems that best meet the project's requirements will also be subjected to abuse tests to assess the safety of the final system.
Development of an electromagnetic jet material characterization probe
The subject falls within the scope of non-destructive testing of the electromagnetic properties of materials.
The aim is to upgrade an existing experimental device based on the use of a radiofrequency probe that extracts the magnetic permeability of the material covering an object from the measured reflection coefficient. Solving the direct problem using numerical simulations allows us to establish charts that are used to solve the inverse problem. The sensitivity to material properties, spatial resolution, and measurement uncertainties of the current device are limited by the antenna. Recent studies have demonstrated the value of using an electromagnetic jet-based probe for characterization with sub-wavelength resolution. Based on this work, the objective is to design and build a new probe that meets the desired performance requirements. The candidate will be responsible for the design and simulation work and then for monitoring the production of the prototypes. He/she will also be responsible for testing these prototypes on reference objects to demonstrate their advantages over the current solution. The new probe will then be integrated into the current measurement system and process
The postdoctoral research will proceed in three main stages. The first will consist of studying the principle of electromagnetic jet antennas and proposing a probe design suitable for the measurement method. Commercial simulation software will be used for the design, followed by internal codes for the validation of the selected prototype. The second stage will involve the manufacture of the prototype, followed by tests with reference samples to validate the concept. Finally, the probe will be integrated into the test bench and the calculation and extraction chain..
Miniaturised analytical method dedicated to the screening of candidate molecules for the capture and removal of radionuclides
This project aims at developing a miniaturized multiplex device dedicated to the screening of the chelating ability of potential molecules for the decorporation of certain radionuclides (RN) from the nuclear power industry, for which current treatments are not satisfactory. The objective is to accelerate the identification of the most promising chelating molecules, while benefiting from the advantages of miniaturisation, such as the consumption of very small quantities of molecules and RN. In a previous project, a phosphated monolith of various lengths has been grafted in situ and characterised in capillaries of 100 µm internal diameter. The quantities of UO22+, Zr4+, Sr2+, Co2+, Cs+ and Ag+ immobilised on these monolithic phases have been measured online by coupling to an ICP-MS.Based on this work, the candidate will be responsible for developing and validating the miniaturised screening method with UO22+, for which data and chelating molecules are available, extending the approach primarily to Zr4+, Sr2+, Co2+, and to fabricate the microfluidic device incorporating parallel microchannels, in order to ultimately screen candidate molecules for distinct RNs in a single fluidic microsystem.
In-situ 4D tracking of microstructural evolution in atomistic simulations
The exponential growth of high-performance computing has enabled atomistic simulations involving billions or even trillions of particles, offering unprecedented insight into complex physical phenomena. However, these simulations generate massive amounts of data, making storage and post-processing increasingly restrictive. To overcome this limitation, on-the-fly (in-situ) analysis has emerged as a key approach for reducing stored data by extracting and compressing relevant information during runtime without significantly affecting simulation performance.
In this context, tracking the four-dimensional (space and time) microstructural evolution of materials under extreme conditions is a major scientific challenge. Atomistic simulations provide a unique spatial resolution to analyze crystalline defects such as dislocations, twinning, vacancies and pores, which govern dynamic phase transformations, melting, damage and mechanical behavior. By capturing their spatio-temporal evolution, it becomes possible to study their statistics, correlations and collective effects in out-of-equilibrium regimes, leading to more accurate predictive material models.
This project builds on advances of the exaNBody high-performance computing platform and a recently developed in-situ clustering method in the ExaStamp molecular dynamics code at CEA. This method projects atomic information onto a 3D Eulerian grid to perform real-time clustering. The objective is to extend this approach to full 4D tracking, enabling the time-resolved monitoring of clusters. This will allow dynamic graph-based analysis of their evolution, including changes in size, shape and temporal behavior, providing new insights into microstructural dynamics at the atomic scale.