Missions

The Laboratoire Leprince-Ringuet (LLR) at École Polytechnique, Palaiseau, France, invites applications for a junior research associate (postdoctoral) position in the field of laser wakefield acceleration and its applications. The position is hosted by the GALOP research group, which is actively involved in national and international programs on plasma-based accelerators. The successful candidate will join a dynamic team under the supervision of Dr. Arnd Specka.
GALOP conducts both experimental and simulation work related to laser-plasma acceleration. This project contributes to the development of compact electron beam optics and diagnostics, essential for advancing the applications of plasma accelerators.

Activities

The main objective of the postdoctoral project is the design, optimization, and implementation of compact focusing optics and beam diagnostics tailored to the specific characteristics of electron beams produced by laser-plasma accelerators. These components will be deployed in experimental campaigns on facilities such as PALLAS, LAPLACE, APOLLON, ELI Beamlines, and EuPRAXIA.
The work will begin by extending an ongoing systematic study within the LLR group on compact focusing devices based on permanent magnets, and will then progress toward exploring applications of laser wakefield accelerators, including biomedical research, positron beam generation, and strong-field QED experiments—particularly those requiring efficient beam capture, conditioning, and diagnostics.
The postdoctoral researcher will have the opportunity to participate in experimental campaigns, analyze data, and supervise student internships within the GALOP group.

Skills

Required qualifications:
• PhD in experimental physics with a background in accelerator or plasma physics.
• Strong academic track record and excellent interpersonal skills.
• Ability to work effectively within a collaborative research environment.
• Excellent command of English, both written and spoken (French not required).
Additional desirable skills:
• Ion optics and charged-particle beam dynamics.
• Beam dynamics simulation codes.
• Accelerator magnet design.
• Particle detection and beam diagnostics.
• PIC simulation codes.
• Data analysis using C++/ROOT and/or Python.
• Detector simulation using GEANT4.

Work Context

Over the past few decades, plasma-based accelerators have evolved from conceptual studies into promising technologies with concrete potential for real-world applications. While their long-term use in high-energy colliders remains a goal, current research is increasingly oriented toward applications in life sciences, material research, and fundamental physics—as reflected in emerging international initiatives such as EuPRAXIA.
LLR is a high-energy physics laboratory affiliated with CNRS-IN2P3, with active groups in both fundamental and applied physics. The GALOP group has a longstanding record in laser-plasma acceleration research, including simulation (it hosts one of the main developers of the SMILEI PIC code) and the development of advanced electron beam diagnostics. The group also operates several test benches for beam magnets and diagnostics, which will be available to the postdoctoral researcher.

Constraints and risks

Occasional trips abroad (Europe) are tp be expected.
During experimental runs (beam time) expect to wiork with cleanroom equipement and conditons (coveralls, mask, headcap, overshoes)is necessary (maximum 4-6 weeks). No exposure to ionizing radiation is foreseen.