FERMI@ELETTRA: The single-pass free-electron laser for the VUV and soft x-ray spectral range at ELETTRA

The FERMI proposal is an initiative from ELETTRA, INFM and other Italian institutes, to construct a single-pass FEL user-facility, to be located next to the third-generation synchrotron radiation facility ELETTRA in Trieste, Italy. For the initial phase, the project aims for lasing from 100 nm to 10 nm, with the use of the existing 1.2-GeV S-band linac. As a next step, the accelerator system should be extended to reach 1.2 nm. In all stages, reliability and flexibility are of importance. That is, seeding schemes are considered to improve the SASE output. In addition, users of this new source will have full control over both wavelength and polarization of the radiation. The initiative is a response to the Italian government's call for proposals for a multi-purpose pulsed laser X-ray source. In anticipation of a positive decision, the Sincrotrone Trieste has initiated the ELETTRA Linac FEL project (ELF), i.e., an R&D project to facilitate a quick and effective implementation of the first step of FERMI. Here, we describe the main features of the project. Emphasis is given to the implementation and initial steps and the ELF project.