G. D'Auria

The FERMI free-electron lasers

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20-4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.

Status report on the ELETTRA RF system

ELETTRA is a synchrotron light source under construction in Trieste (Italy) that works with beam energies of between 1.5 and 2 GeV. The results of the RF system development are presented. The power plant and the RF cavity are described. The low-level control of the cavity is considered. The higher-order-mode suppressor for the ELETTRA RF cavities is discussed. A complete power plant has been tested on a dummy load, and the cavity feedthrough has been developed. The progress work on the accelerating cavity is described.<<ETX>>

The new elettra booster injector

The new full energy injector for Elettra is under construction. The complex is made of a 100 MeV linac and a 2.5 GeV synchrotron, at 3 Hz repetition rate. With the new injector top-up operation shall be feasible. In the first semester of 2007 the machine assembly has been started. Start of the commissioning is scheduled in Summer 2007, while the connection to the Storage Ring is planned in Fall. This paper reports the project status.

Linac upgrading program for the FERMI project: Status and perspectives

FERMI@ELETTRA is a soft X-ray fourth generation light source under development at the ELETTRA laboratory. It will be based on the existing 1.0-GeV linac, revised and upgraded to fulfill the stringent requirements expected from the machine. The overall time schedule of the project is very tight and ambitious, expecting 10 nm photons for users by 2010. Here the machine upgrade program and the ongoing activities are presented and discussed.

Elettra Present and Future Upgrades

During the last year, the third generation synchrotron light source ELETTRA could fully benefit of several upgrades that have been implemented in the frame of a project to enhance the quality of the light source. The super conducting third harmonic cavity, the feedbacks, the realignment of the whole ring and other improved devices have allowed to further, significantly optimize the beam stability and lifetime, as well as the operability and uptime of the facility. At the same time two large-scale projects are underway that will change the perspectives of the whole ELETTRA laboratory, namely the full energy booster injector and the single pass X-ray FEL FERMI@Elettra, based on the existing linac. Their status will be presented here together with the overview of the existing light source.

Optical transition radiation measurements on the Elettra Linac

An experimental apparatus has been developed and installed on the Elettra Linac in Trieste in order to measure OTR spectra at energies below 100 MeV. In this paper we report the results so far obtained at electron energies between 30 and 100 MeV. Beam diagnostics obtained from OTR data will be discussed.

A nearly monochromatic cavity for high current storage rings

Abstract A strong damping of the higher order mode (HOM) spectrum of an RF cavity can be obtained by coupling appropriate waveguides directly to the cavity. This type of HOM suppression has been investigated at S.T. After studies and tests on different shapes of cavities, particularly on bell-shaped cavities, it has been decided to design a pill-box cavity for the ELETTRA Storage Ring. A prototype of this cavity has been produced with two waveguide suppressors coupled to it. The suppression effect on the HOM spectrum is described along with discussions on the vacuum window design and on the shape and the material for the waveguide load. The effects on the accelerating mode are shown as well.

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 governments 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.