Description du sujet de thèse

The proposed doctoral research is situated in the field of accelerator physics, focusing on beam dynamics in Energy Recovery Linacs (ERLs). ERLs are an emerging class of accelerators that combine the flexibility and high beam quality of linear accelerators with the efficiency of recirculating machines. PERLE (Powerful Energy Recovery Linac for Experiments), currently under design at IJCLab within the PERLE@Orsay international collaboration, will serve as a demonstrator for this technology. With design parameters of up to 500 MeV beam energy and 20 mA current (corresponding to 10 MW beam power), PERLE offers an unprecedented platform for exploring high-current beam dynamics phenomena relevant to future facilities such as the LHeC.
The thesis will pursue a detailed study of beam halo formation and mitigation strategies in PERLE, addressing critical issues for the stability and safe operation of ERLs. Using BMAD simulation tool, an advanced open-source particle tracking framework, the doctoral candidate will perform start-to-end simulations, benchmark physical models, and explore tolerance studies. Specific research themes include: off-momentum collimation in merger and arc sections, influence of higher-order magnetic harmonics, alignment errors and mechanical tolerances, wakefield effects in beam combination magnets, and beam–gas interactions that determine vacuum requirements.
Beyond its scientific contribution, the objective of the thesis is to develop and promote the expertise of the doctoral researcher in cutting-edge accelerator modelling, enabling them to disseminate results in leading conferences and journals, and contribute to the international visibility of PERLE.
Bibliographical references :
D. Angal-Kalinin PERL E. Powerful energy recovery linac for experiments. Conceptual design report, J. Phys. G 45, 065003 (2018), arXiv:1705.08783 [physics.acc-ph].
S. A. Bogacz et al., Beam dynamics driven design of powerful energy recovery linac for experiments, Phys. Rev. Accelerators and Beam 27, 031603 (2024)

Contexte de travail

IJClab is a laboratory of physics of the two infinities under the umbrella of the CNRS and the University of Paris-Saclay. The laboratory's research focuses on nuclear physics, high-energy physics, astroparticles and cosmology, theoretical physics, accelerators and particle detectors, as well as technical research and development and associated applications for energy, health, and environment. The laboratory has important technical staff (approximately 280 engineers and technicians) specialized in all the major fields required to design, develop and implement the instruments required for its scientific activities: mechanics, electronics, computer science, instrumentation, acceleration techniques, and biological techniques. The laboratory has also developed important on-site research infrastructure and technological platforms.
IJCLAB bases its recruitment policy on the promotion of equality, diversity and inclusion. Essential values, they allow the professional development of agents, who are real actors in a collective success, but also the development of the laboratory itself.
The IJCLab Accelerator Physics Center represents 80% of CNRS research in this field. It consists of four research teams, two departments, and one platform. The BIMP team counts 22 researchers including 13 permanent staff, 6 doctoral students, and 3 postdoctoral fellows, in addition to fixed-term contracts and visiting staff. Its activities focus on cutting-edge research in accelerators. The team's major projects include FCC, ThomX, PERLE, MYRRHA, and DESIR. Within the framework of PERLE, the needed expertise in beam dynamics is fully integrated in the BIMP team.
The doctoral student will be a student at the University of Paris-Saclay attached to the doctoral school of Particles, Hadrons, Energy and Nucleus: Instrumentation, Image, Cosmos and Simulation (PHENIICS).
This work will be carried out within the collaborative framework of PERLE@Orsay, ensuring close interaction with accelerator physicists, magnet designers, and vacuum specialists. The student will benefit from the financial and material support of the PERLE project, which is funded through CNRS, European and international collaborations.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The successful candidate shall be enrolled on a PhD program of the PHENIICS doctoral school. A secondment of approximately one month's duration in Japan should be expected. Travel to France and Europe is expected for PERLE project meetings and conferences in the field.

Informations complémentaires

• deep knowledge in accelerator physics
• Python (or C++, Fortran) coding
• analytical skills
• basis of data analysis
• a high level of communication skills, both oral and written (French and English required) to be able to present at conferences and write articles in scientific publications
• ability to work in a team
• ability to work independently, organisational ability and ability to account for one's own actions

The candidate must have a degree in engineering and/or a Masters in Physics.
Applications must include a detailed CV; at least two references (people who may be contac¬ted); a cover letter of one page; a one-page résumé of the dissertation for the Masters; grades for the Masters 1 or 2 or the engineering degree.
We are looking for a PhD fellow who will be able to become fully involved with the project, with a thirst for knowledge, a certain independence of thought and strong motivation to develop skills in the field of accelerator physics. In addition, the candidate must be able to work in a team on multi-disciplinary projects.