COXINEL: Towards free electron laser amplification to qualify laser plasma acceleration

The advent of X-ray Free Electron Lasers (FEL), unique powerful tuneable, short pulse lasers in the X-ray light source landscape enables new matter investigations. Besides, Laser Plasma Acceleration (LPA) had made these last decades significant progress and enabled the acceleration of electrons with GeV/mm. The achieved electron beam performance still do not meet these of the conventional linear accelerators used for FEL, especially in terms of divergence, energy spread and stability. FEL can thus be viewed as an application to qualify LPA based electrons. Electron beam manipulation is still required to fit the FEL requirements, in particular to handle the energy spread and the divergence. An electron beam transfer line, specifically designed and built at SOLEIL in the frame of the European Research Council (ERC) grant COXINEL, has been installed at Laboratoire d'Optique Appliquee (LOA) for first tests with LPA electrons. (author)