Laser-plasma accelerators

Electron accelerators are widely used in scientific, industrial and societal applications, with applications ranging from cancer therapy, gamma-ray imaging for non-destructive inspection, to electron welding-cutting and particle physics. Most accelerators rely on radio-frequency (RF) cavities for accelerating particles. While RF technology is very mature, the accelerating gradient is limited by breakdown of the cavity walls to 10-100 MV/m, which explains the large size of high energy machines. In this context, laser-plasma based particle acceleration is currently being considered as a promising emerging technology for addressing some limitations of RF accelerators.

Movie showing the physics of laser-plasma acceleration

In a laser-plasma accelerator1,2 (LPA), an ultra-intense and ultra-short laser pulse is focused into a plasma and drives a plasma wave that accelerates electrons, see movie. The accelerating fields reach values in excess of 100 GV/m, i.e. 3 to 4 orders of magnitude higher than in RF-accelerators, allowing electrons to be accelerated to 100 MeV energies in millimeters3,4, and GeV in centimeters5,6. Therefore, this technology has the potential to miniaturize electron accelerators. In addition, LPAs deliver electron beams with unique properties: the electron bunch has femtosecond duration and a point-like transverse source of a few micrometers only. These properties, in conjunction to the compact size of the accelerator, open new opportunities for industrial and societal applications.

LAPLACE : a new platform for laser-plasma accelerators

LAPLACE will be the first French scientific platform fully dedicated to laser-plasma accelerators. The research will cover a wide range of activities with the motivation of bringing LPAs to a higher level of scientific maturity.

The LAPLACE High-Energy platform will focus on scientific exploration and proof-of concept experiment for:

  • All optical guiding for GeV beam acceleration. Laser spatio-temporal shaping for enhanced acceleration
  • Developing new X-ray source concepts, e.g. betatron7, Inverse Compton Scattering8, Free Electron Lasing9
  • Developing beam-driven experiments for ultra-high quality beams

The LAPLACE High-Repetition platform, on the other, hand will push the engineering aspects of LPAs:

  • Develop high-power laser technology, in collaboration with THALES
  • Develop a high-repetition (>100 Hz), high-energy (>100 MeV) LPA10
  • Run a LPA “like a machine” with high robustness and reliability
  • Develop applications of the high-repetition rate LPA in non-destructive testing, radiotherapy and ultrafast dynamics for material science

LAPLACE is located at Laboratoire d’Optique Appliquée (LOA). LOA is a pioneer laboratory in the field of laser-plasma acceleration3,4,6,10 and plasma based X-ray generation6,7,8.


[1] Tajima & Dawson, “Laser electron accelerator”, Phys. Rev. Lett. 43, 4 (1979)

[2] Esarey et al., “Physics of laser-driven plasma-based electron accelerators”, RMP 81, 1229 (2009)

[3] Faure et al., “A laser-plasma accelerator producing monoenergetic electron beams”, Nature 431, 541 (2004); see also Mangles et al, 431, 535 and Geddes et al, 431, 538  in the same issue of Nature (2004).

[4] Faure et al., “Controlled injection and acceleration of electrons in plasma ”, Nature 444,737 (2006)

[5] Leemans et al. , “Multi-GeV electron beams from capillary discharge guided subpetawatt laser pulses in the self-trapping regime”, PRL 113, 145002 (2014)

[6] Oubrerie et al., “Control acceleration of GeV electron beams in an all-optical plasma waveguide”, Light: Science & Applications 11, 180 (2022)

[7] Rousse et al., “Production of a keV X-ray beam from synchrotron radiation in relativistic laser-plasma interaction” Phys. Rev. Lett. 93, 135005 (2004)

[8] Ta Phuoc et al., “All optical Compton gamma-ray source”, Nat. Photonics 6, 308 (2012)

[9] Corde et al, “Femtosecond X-rays from laser-plasma accelerators”, RMP 85, 1 (2013)

[10] Guénot et al., “Relativistic electron beams driven by kHz single-cycle light pulses”, Nat. Photonics 11, 293 (2017)