Missions

In this project, you will be responsible for conducting numerical simulation campaigns aimed at assessing the benefits of HOFI channels for laser wakefield acceleration (LWFA). Your mission will involve applying multi-physics approaches to address both the long time scales required for channel formation and the ultrafast processes involved in LWFA.

You will use the PIC code Smilei to model short time-scale phenomena (plasma ionization, initial heating, and LWFA dynamics within the formed channel). You will also employ hydrodynamic and/or Fokker-Planck codes to simulate the initial plasma expansion leading to the creation of the HOFI channel. Setting up a simulation chain integrating these different tools will be part of your tasks.

Finally, you will analyze and compare your numerical results with data obtained from previous experimental campaigns.

Activities

- Conduct numerical simulations to evaluate the benefits of HOFI channels for LWFA.
- Run and combine plasma simulation codes on national HPC platforms.
- Develop multi-physics workflows by coupling different simulation tools.
- Analyze and interpret simulation results, comparing them with experimental data.
- Contribute to the design of future experiments to improve laser guiding.

Skills

- Solid knowledge of laser–plasma interaction physics.
- Comfortable working in collaborative HPC environments (Linux, SSH, Git, Slurm, etc.).
- Strong skills in Python for data analysis and visualization.
- Clear communicator with proven ability to write, synthesize, and present scientific results.

Work Context

Laser wakefield acceleration (LWFA) is capable of generating accelerating fields three orders of magnitude larger than what is currently done in standard RF cavities. It is therefore considered as a promising alternative for future accelerators and spectacular progresses have been made during the last 20 years. These progresses were possible thanks to the convergence of the considerable experimental efforts invested on this topic and critical improvements of Particle-In-Cell (PIC) numerical simulations. This convergence is particularly visible in Saclay's area where a large community of computer scientists is structured around the PIC code Smilei, and where several ultra-high intensity laser facilities are collaborating toward the construction of a laser-plasma based accelerator. The physics of LWFA offers many challenges and one of them is the stable guiding of the laser pulse over distances long enough to reach high energies. One promising lead on this topic is the use of hydrodynamic optical-field-ionized (HOFI) channel in the plasma target to allow for longer and more stable laser-plasma interaction.