Among numerous research areas in the laser acceleration field, SACM is currently focusing on laser-plasma electron acceleration, which should, in the short and medium term, have applications in many fields: compact X-ray and gamma ray sources, high-energy physics, health technology, etc.
Laser-plasma acceleration has been demonstrated to attain fields up to three orders of magnitude greater than conventional acceleration techniques, and should lead to a drastic reduction in the size and cost of future electron accelerators. Significant advances have been made in the last decade (e.g. acceleration of electrons up to 4.25 GeV in a capillary at the LBNL in Berkeley) in the production of radiation by different mechanisms such as Betatron and Compton sources, and with electromagnetic undulators. However, there are still major hurdles to overcome before compact sources that genuinely meet users’ needs can be built, and certain aspects of beam performance, such as energy spread, stability, and the charge of the accelerated bunches, still require improvement.
These activities are based around the CILEX-APOLLON interdisciplinary center, a joint facility used by the various entities involved at the Université Paris-Saclay (11 laboratories):
? Research on the experimental facility in the “Long Focal” area at CILEX-APOLLON in Orme des Merisiers, dedicated to the laser-plasma acceleration of electron beams.
- Within the LFA project group, SACM is in charge of beam dynamics calculations and beam transport line design; in particular it is responsible for the transport line design for the “two-staged scheme” (injector and accelerator).
- These activities should soon be extended to include computations for the simulation of plasma structures, and the design and implementation of beam diagnostics.
? R&D: design and construction of the compact transport and analysis line for the laser-plasma injector at the local UHI100 facility at IRAMIS/LIDYL.
- In the context of DACTOMUS, IRFU/SACM carried out the optics studies and supplied the magnetic components: the triplet formed of three quadrupoles with permanent magnets and a spectrometer consisting of a permanent magnet dipole.
PARTICIPATION IN THE EUROPEAN EURONNAC NETWORK
The EuroNNAc (European Network for Novel Accelerators) network links the major European laboratories and universities (more than 50 institutes) involved in R&D on new acceleration techniques. Plasma acceleration is the main component of this R&D. IRFU/SACM joined the network in May 2014. Its purpose is to encourage exchanges between laboratories and to foster discussion about new acceleration techniques at European level.
PARTICIPATION IN THE EUPRAXIA DESIGN STUDY
IRFU is heavily involved in the Horizon 2020 program’s European EuPRAXIA Design Study. This project (European Plasma Research Accelerator with eXcellence In Applications) will produce a conceptual design report for a European plasma research accelerator for novel technological applications. An implementation model will be proposed, including a comparative study of possible sites in Europe, a cost estimate and a model for distributed construction but installation at one central site. As a new large research infrastructure, EuPRAXIA would place Europe at the forefront of the development of plasma accelerators driven by the world’s most powerful lasers from European industry in the 2020s. The EuPRAXIA consortium includes 16 laboratories and universities in five EU Member States. A further 18 partners from eight countries are also involved, including leading-edge institutes in the field in Europe, Japan, China and the United States.
Besides contributing to the definition of the accelerator’s overall parameters and the installation model, SACM is coordinating the numerical simulations carried out using PIC (Particle-in-Cell) codes in order to optimize the plasma and laser parameters and the electron beam qualities.