EXTENSION OF THE MAX IV LINAC FOR A FREE ELECTRON LASER IN THE X-RAY REGION

The 3GeV linac for the MAX IV laboratory is currently under construction in Lund (Sweden). As full energy injector for the MAX IV rings, a thermionic gun will be used to create electrons. However a photocathode gun planned for a short pulse facility will deliver small emittance and ultra-short electron bunches that will be suitable to also drive a Free-Electron Laser. Moreover extending the linac energy with 1 or 2GeV will give the opportunity to get closer to 1 ˚ A radiation with much more flexibility and better performances. Given these opportunities at the MAX IV laboratory, a free electron laser is envisaged in the long term perspective of the facility. In this study we investigate the case of a 5GeV machine which can produce radiation in the X-ray region. The FEL design will benefit from the implementation of self-seeding, to enhance stability of the central wavelength and spectral bandwidth. Tapering along variable gap undulators will help to extract the maximum photon flux and increase the brilliance of the source. Among others, this kind of machine would be suitable for time resolved experiments and imaging.