Date: Friday 7th November 2025 at 11:00 GMT (UK time)
Speaker: Dr Marie Labat, Researcher at Synchrotron SOLEIL
Abstract
Free electron lasers (FELs) are ultra-brilliant light sources relying on relativistic electron bunches wiggling in a magnetic field. Conventional FELs, which have been in operation for several decades, are based on radio-frequency (RF) accelerators. However, for the delivery of ultra-short wavelength radiation (X-rays), the energy of the electron beams has to measure in the few GeV range, which typically requires km long RF accelerating structures. Laser plasma accelerators, with their higher accelerating gradients, could help in reducing the footprint of these short wavelength FELs. After the first proof-of-principle experiments, several groups are now aiming to improve the performance of laser plasma based FELs and to demonstrate their compatibility with users. In this seminar, the recent results obtained on the COXINEL @HZDR laser plasma based FEL will be presented.
The seminar can now also be found on YouTube: https://youtu.be/Y_qqN0ArxRo
Biography
Dr Marie Labat did her PhD on the seeded free electrons lasers (FELs) of UVSOR-II (Japan) and SPARC (Italy). In 2010, following working on commissioning the SPARC FEL as a post-doctorate, she joined the Diagnostics and Synchronization Group of the Accelerator Division of Synchrotron SOLEIL. Since then, she has led a research activity essentially oriented towards the use of synchrotron radiation for beam diagnostics and the development of laser plasma based FELs.
Beam diagnostics are essential for the development and the operation of accelerators. Marie Labat has specialized in indirect electron beam diagnostics which use the synchrotron radiation produced by the electron beams in accelerator magnets to infer their transverse and longitudinal properties. She is in charge of these diagnostics for the characterization of the beam on the three accelerators at Synchrotron SOLEIL (linac, booster and storage ring).
In parallel, Marie Labat has continued her work on FELs. Upon arriving at SOLEIL, she joined the French LUNEX project, led by M.E. Couprie, to work on the new concept of laser plasma based FEL. In 2014, COXINEL, a sub-task of LUNEX, received an ERC grant. COXINEL aimed to demonstrate the first laser plasma based FEL in a seeded configuration. Designed and built at SOLEIL, the COXINEL beamline was first installed at Laboratoire d'Optique Appliquée (France) for preliminary experiments. In 2021, the beamline was moved to Helmotz-Zentrum Dresden-Rosendorf (Germany) and the first
demonstration was obtained at 270 nm in 2022. Marie Labat is a key member of the COXINEL team, carrying out experimental campaigns and numerical simulations. The experiments on COXINEL are pioneering the development of laser plasma based FELs, a research topic on the EuPRAXIA roadmap.
