Description du sujet de thèse

The concept of Energy Recovery Linacs (ERLs) is a pioneering innovation in accelerator physics. An ERL combines the beam quality typical of linear accelerators (linacs) with significantly reduced energy consumption, enabling the circulation of high-current beams. PERLE is a high-current ERL demonstrator currently under study at IJCLab, designed to (re-)circulate an electron beam up to 250/500 MeV with a current of 20 mA, corresponding to a total beam power of 5 to 10 MW.
The hybrid nature of ERLs places them at the intersection of existing accelerator technologies — neither a traditional linac nor a synchrotron. As such, a wide range of physical effects may coexist (e.g., CSR phenomena typical of circular machines, or HOMs in linacs). This complexity requires the use of innovative and versatile simulation methods, as well as extensive benchmarking efforts. Moreover, the high beam currents involved in PERLE (20 mA CW for 5–10 MW of power) make the accelerator highly sensitive to nonlinear effects such as collective interactions, residual gas scattering, and cavity harmonic distortions.
This PhD project is part of the international PERLE@Orsay collaboration, which aims to construct a multi-pass, high-power ERL by 2029. The doctoral work will begin with an in-depth study and adaptation of the BMAD code — an open-source, flexible particle tracking library — ensuring its reliability in modeling a wide variety of physical effects. The second phase of the work will focus on beam transport throughout the accelerator (so-called “start-to-end” tracking), with a particular emphasis on compensating longitudinal effects, such as higher-order momentum compaction factor (1st, 2nd, and 3rd order), and controlling the beam's longitudinal phase space to meet the specific requirements of the experiments hosted by the accelerator.
The selected candidate will be expected to publish their research in peer-reviewed journals and to present their work regularly at national and international conferences.
Références :
PERLE conceptual design report : https://iopscience.iop.org/article/10.1088/1361-6471/aaa171
Beam dynamics driven design of PERLE : https://hal.science/hal-04523882
Energy Recovery Linacs : https://www.nature.com/articles/s42254-023-00644-6
Self consistent longitudinal match of PERLE : https://arxiv.org/abs/2111.15372

Contexte de travail

The Irène Joliot-Curie Laboratory for the Physics of the Two Infinities (IJCLab) is a research institute in physics under the supervision of CNRS, Université Paris-Saclay, and Université de Paris. The selected candidate will be enrolled in the PHENIICS doctoral school (Particules Hadrons Energie et Noyau : Instrumentation, Image, Cosmos et Simulation) at Université Paris-Saclay, and will join the BIMP team (Beam Instrumentation and Manipulation Physics) within IJCLab's Accelerator Division. This research group provides an ideal environment for accelerator design and associated instrumentation in the fields of particle and nuclear physics.
The PhD work will take place within an international collaboration, in close contact with experts in accelerator physics. The local team includes accelerator physicists specialized in beam dynamics and the development of beam instrumentation.
As the first phase of the PERLE project is already largely funded, commissioning tests of the first accelerator components may be conducted during the thesis. The team also benefits from significant computational resources, including dedicated PCs, computing clusters, and access to national data centers.
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.

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

Short-term international travel (approximately one week) is expected, primarily to attend conferences in the USA, Japan, and Europe.
A long-term research stay (over one month) in Japan could be considered as part of the project.
Should beam tests be conducted on site, the candidate may be required to work in a controlled radiation area (Category B), in compliance with safety regulations.

Informations complémentaires

The candidate must hold an engineering degree or a Master's degree in physics, preferably with a specialization in accelerator physics. Prior training through programs such as CAS or JUAS is considered an asset.
As the project is part of an international collaboration, fluency in both spoken and written English is essential. Knowledge of French is recommended.
Additional desired skills include:
– Strong writing ability and the capacity to formulate and carry out a scientific project
– Teamwork skills and the ability to collaborate in a multidisciplinary environment
– Autonomy, organizational skills, and accountability
– Critical thinking, synthesis skills, initiative, and resilience
Applications should include:
– A CV without any break in date showing diplomas, titles and work and professional experience.

– A one-page cover letter
– Transcripts from Master 1 and 2 (or equivalent)
– One or more letters of recommendation (optional, but encouraged)
Submit a covering letter