Missions

The post-doc will be part of the PhLIPPER team at LULI (Laboratoire pour l'Utilisation des Lasers Intenses) at École Polytechnique. This position is part of the g4QED project and the operation of the Apollon multi-petawatt laser, with the aim of studying and developing sources of very high-energy gamma photons in the strong-field regime of quantum electrodynamics (SF-QED).

The project involves theoretical and numerical support for experiments carried out at Apollon (and other facilities), both for the study of laser-target interaction conditions and the design of appropriate diagnostics, and for data interpretation. Simulations will be carried out using (i) the PIC code Smilei, and the development of specific physics modules (Bremsstrahlung, Bethe-Heitler) ported to GPUs; (ii) the MoteCarlo codes (Geant4 and FLUKA).

Activités

The list of the main activities of the person recruited will be as follows :

- Interpretation of experiments carried out on Apollon to produce gamma photons (MeV to GeV) by laser-plasma interaction.
- Modeling of gamma photon emission processes (Bremsstrahlung, nonlinear inverse Compton scattering) and electron-positron pair production.
- Development and implementation of Monte-Carlo modules in the Smilei code to simulate these processes.
- Porting and optimization of these modules on GPU architectures, in collaboration with the Maison de la Simulation (MdlS).
- Modeling, simulation and optimization of suitable diagnostics for high-energy photons and particles.
- Development of analysis and deconvolution techniques.
- Participation in the supervision of Master's-level student research projects and in the development of an e-learning offer using Smilei as part of the EUR Plasma Science et Technologie program.
- Dissemination of results through scientific articles and presentations at international conferences.

Compétences

The expected skills are :

- Plasma physics, laser-plasma interaction, or strong-field quantum electrodynamics.
- Solid skills in numerical simulation (Particle-In-Cell and Monte-Carlo), with experience on codes such as Smilei, WarpX, EPOCH, PIConGPU, Geant4.
- Experience in developing and optimizing scientific codes, especially on parallel architectures and GPUs.
- Good knowledge of radiation processes in laser-plasma interaction (Bremsstrahlung, inverse Compton, SF-QED).
- Proven skills in plasma physics experimental data analysis.
- Very good command of English, both written and spoken; mastery of French would be an asset but is not mandatory.
- Autonomy, initiative, adaptability, interdisciplinary teamwork and teaching skills.

Contexte de travail

The position is at the Laboratoire pour l'Utilisation des Lasers Intenses (LULI), a joint research unit (UMR) of École Polytechnique, CNRS, CEA and Sorbonne University. The laboratory is located on the École Polytechnique campus (Palaiseau), at l'Orme des Site des Merisiers (Saclay) and on the Jussieu campus of Sorbonne Université in Paris. The laboratory has a staff of 100 (65 engineers and technicians and 35 researchers). It is a center for academic research and training in hot plasma physics and laser optics. The LULI laboratory provides the scientific community with competitive laser chains and experimental facilities for research into the physics of hot, dense plasmas created by lasers. LULI plays a key role in the development of very high intensity lasers, in particular the Apollon laser.
The project is part of a collaborative framework with other laboratories on the Saclay plateau (CEA, LOA, etc.), notably via the development of the Smilei code and the carrying out of collaborative experiments. Collaboration with the Maison de la Simulation will enable us to benefit from advanced expertise in high-performance computing and software optimization on GPUs.


The position is located in a sector covered by the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival be authorised by the competent authority.

Contraintes et risques

Short-term travel in France (in particular to the Apollon facility) and abroad (conferences, collaborations) are to be expected.