Maël Le Garrec

About

I am a postdoctoral researcher at CNRS/IN2P3-LAPP in Annecy and a CERN Research Associate. I work on the FCC-ee: how ground motion and vibrations move the beams and reduce the luminosity, and the design of its high-temperature superconducting final-focus magnets.

I did my PhD at CERN with Goethe-Universität Frankfurt (magna cum laude), measuring and correcting non-linear magnetic errors in the LHC. Several of them had never been observed before. Since 2024 I also spend about a month a year at KEK, measuring the optics of SuperKEKB.

I came to physics from computer science: I graduated from EPITA and worked as a DevOps engineer at Scaleway and a security engineer at La Poste. I still write a lot of code, mostly the Python tools used to measure and correct accelerator optics.

I am open to research and R&D roles combining physics modelling and scientific software.

Research

• FCC-ee: impact of vibrations and ground motion on the beams and the luminosity, including the final focus quadrupoles; tracking with Xsuite.
• LHC: non-linear optics measurements and corrections. First observations of 4^th and 5^th order chromaticity, chromatic amplitude detuning, and dodecapole and decatetrapole fields.
• SuperKEKB: first measurements of sextupolar and octupolar resonance driving terms on both rings.

PhD thesis

LHC Effective Model for Optics Corrections: measurements and corrections of high-order non-linear optics – Goethe-Universität Frankfurt, 2025 (CERN-THESIS-2024-336)

Publications

Selected

• 2026
  Measurement, Modeling, and Correction of Decapolar Hamiltonian terms in the LHC Editors' Suggestion
  M. Le Garrec, E.H. Maclean, R. Tomás, F. Carlier – Phys. Rev. Accel. Beams
• 2026
  Luminosity Loss from Ground Motion in the FCC-ee: MDI and Arc Quadrupole Vibration Studies
  M. Le Garrec et al. (6 authors) – IPAC'26
• 2025
  Coherent Plane Ground Wave Impact on the FCC-ee Beam Centroid
  M. Le Garrec et al. (9 authors) – IPAC'25
• 2023
  First measurement of fourth and fifth order chromaticity in the LHC
  M. Le Garrec et al. (13 authors) – IPAC'23
• 2023
  Measurement and modelling of decapole errors in the LHC from beam-based studies
  M. Le Garrec et al. (7 authors) – IPAC'23
• 2023
  First operational dodecapole correction in the LHC
  J. Dilly, …, M. Le Garrec et al. (10 authors) – Phys. Rev. Accel. Beams 26

All publications and talks

43 publications (6 as first author), 14 conference talks and posters, and 49 working-group talks. Click a category to expand it.

Also on INSPIRE and ORCID.

Software

I contribute to the open-source pylhc tools of the CERN Optics Measurements and Corrections team, used at the LHC, the SPS and SuperKEKB:

• omc3 – optics analysis and corrections (higher-order RDTs, SPS data reader, …)
• turn_by_turn – reading BPM data from many machines, including SuperKEKB
• PyLHC – BPM calibration and SuperKEKB BPM synchronisation
• tfs-pandas, sdds, generic_parser – file formats and utilities used across these tools

Elsewhere

• Photography
• Blog – notes on science and programming
• Bitbucket – personal projects

Contact

E-mail: mael@legarrec.org
LinkedIn: le-garrec
IRC: hatrix on Libera