Post-doc in numerical study of flying focus for laser-wakefield acceleration. (M/F)

CNRS; France; Sur place; EUR 42 000 - 54 000; Plein temps

Résumé du poste

CNRS LOA in France seeks a First Stage Researcher (R1) to lead numerical studies of flying-focus laser pulses for laser wakefield acceleration. You will perform PIC simulations and analyze interactions with plasma using advanced optical propagation models.

The role involves collaborating with UPX group, advancing analytical models, and contributing to scientific articles and conferences, with an emphasis on teamwork and excellent communication.

Qualifications

• PhD in Physics with strong interest for plasma simulations.
• Prior experience with laser-plasma simulation, especially with Particle-in-Cell codes.
• Expertise in one of the followings: laser-plasma accelerators, high-intensity lasers, laser-plasma interaction, optics.
• Ability to work in team, coordinate with PhD students.
• Good oral and written communication skills in order to write scientific articles and present results in international conferences.

Responsabilités

• Development and implementation of numerical simulations of flying-focus pulse propagation and its interaction with the plasma (Particle-in-Cell codes and optical propagation).
• Exploration of spatio-temporal configurations to optimize electron injection, acceleration, and X-ray generation.
• Analysis and interpretation of simulation results, in connection with the project's experimental campaigns.
• Development of analytical models to describe the laser-plasma interaction.
• Interaction with the experimental teams to help guide the campaigns and compare simulations with measurements.
• Scientific communication: writing scientific articles and participating in conferences.

Connaissances

Plasma simulations

PIC codes

Laser-plasma accelerators

High-intensity lasers

Laser-plasma interaction

Optics

Formation

PhD in Physics

Outils

Particle-in-Cell codes

Description du poste

Organisation/Company CNRS Department Laboratoire d'Optique Appliquée Research Field Physics Researcher Profile First Stage Researcher (R1) Application Deadline 1 Nov 2026 - 00:00 (UTC) Country France Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Feb 2027 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Laser-plasma accelerators (LPAs) are a compact alternative to conventional accelerators and can generate ultra-relativistic electron beams over centimeter-scale distances thanks to extreme accelerating fields ( over 100 GV/m). A key limitation for beam energy is the dephasing between accelerated electrons and the plasma wake: electrons eventually outrun the accelerating phase, which caps the effective acceleration length and final energy. We explore a dephasing-free concept based on superluminal laser pulses, where the focal point can be made to propagate through the plasma at an arbitrarily controlled velocity, including faster than the speed of light in vacuum. This is achieved by combining an axiparabola, which focuses each annular portion of the near-field at a different longitudinal position, with a controlled radial delay introduced via spatiotemporal couplings (STC). Additionally, flying focus relies on a one-to-one mapping between the radial position on the optic and the longitudinal position along the focal line, so that each slice of the line can in principle be shaped independently thus opening the door to controlling not just group velocity but the pulse's full set of parameters as it propagates.
selected candidate will lead the numerical study of flying-focus laser pulses for laser wakefield acceleration, in close collaboration with the experimental programs on 100's TW-class and petawatt lasers. The work will focus on simulating flying-focus pulse propagation and its interaction with the plasma during acceleration using particle-in-cell (PIC) simulations, with particular attention to the ultrashort, sub-10 fs regime. Another key research direction will be to explore spatio-temporal configurations to tailor focal-line parameters such as position, duration or intensity so as to enhance electron injection, acceleration, or X-ray generation.

• Development and implementation of numerical simulations of flying-focus pulse propagation and its interaction with the plasma (Particle-in-Cell codes and optical propagation).
• Exploration of spatio-temporal configurations to optimize electron injection, acceleration, and X-ray generation.
• Analysis and interpretation of simulation results, in connection with the project's experimental campaigns.
• Development of analytical models to describe the laser-plasma interaction.
• Interaction with the experimental teams to help guide the campaigns and compare simulations with measurements.
• Scientific communication: writing scientific articles and participating in conferences.

The Laboratoire d'Optique Appliquée (LOA) is a joint research unit of CNRS/École Polytechnique/ENSTA Paris, located on the École Polytechnique campus in Palaiseau. A pioneer in laser-matter interaction and plasma physics for over 30 years, the laboratory's research covers a broad range of topics in ultrafast science, including the development of ultra-intense femtosecond laser systems, the physics of laser filamentation in air, and the realization of compact sources of radiation and energetic particles for academic, societal, and industrial applications. The selected candidate will join the Ultrafast Sources of Particles and X-rays (UPX) group. The position falls within a sector subject to the protection of scientific and technical potential (PPST) and therefore requires, in accordance with regulations, that your arrival be authorized by the competent authority of the MESR.

• PhD in Physics with strong interest for plasma simulations.
• Prior experience with laser-plasma simulation, especially with Particle-in-cell codes.
• Expertise in one of the followings: laser-plasma accelerators, high-intensity lasers, laser-plasma interaction, optics.
• Ability to work in team, coordinate with PhD students.
• Good oral and written communication skills in order to write scientific articles and present results in international conferences.