M. Ferianis

Mechanical Vibration Measurements on TTF Cryomodules

Few of the TTF cryomodules have been equipped with Wire Position Monitors (WPM) for the on line monitoring of cold mass movements during cool-down, warm-up and operation. Each sensor can be used as a detector for mechanical vibrations of the cryostat. A Digital Receiver board is used to sample and analyze with high frequency resolution, the WPM picked up signals, looking to its amplitude modulation in the microphonic frequency range. Here we describe the new acquisition system and show the first vibration spectra detected during normal operation of the TTF cryomodules # 4 and # 5.

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.

The new low gap BPM system at ELETTRA: Description and prototype tests

A prototype Low Gap BPM system has been installed at ELETTRA and it is now undergoing the first tests. The main purpose of this system is to provide ultra-stable position signals, at the micrometer level, to the Orbit Feedback processors. The system consists of a new Low Gap monitor and a new digital BPM electronics. The monitor was designed at ELETTRA and fits to the 14 mm low gap ID vacuum chamber. Full advantage has been taken from the reduced gap button distance. To reach maximum stability of the BPM itself, a new support system has been designed where, by means of two bellows, the BPM movements are de-coupled from the vacuum chamber slow drifts. Furthermore an external system monitors the BPM position with respect to a reference column made of carbonium. The Low Gap BPM system adopts the digital BPM electronics that was conceived at the Paul Scherrer Institut for the Swiss Light Source (SLS). One of its features is the programmable bandwidth that offers sub-micron position data when set to low bandwi...

The Cavity BPM for the microwave measurement of the transversal position of relativistic electron bunches travelling in a vacuum beampipe

The free electron laser (FEL) is a fourth-generation light source based on the interaction between electromagnetic fields and ultra-relativistic electron bunches which travel along the axis of a vacuum beampipe. The Cavity Beam Position Monitor (Cavity BPM) is a new kind of diagnostic tool for measuring the beam displacement from the beampipe axis. At the “Sincrotrone Trieste S.C.p.A.”, Italy, a seeded FEL, presently under development for the FERMI@Elettra project [1], will provide an ultra bright coherent X-ray light which will be employed for the study of chemical reactions and dynamic molecular processes. This paper presents the Cavity BPM and a new measurement system, with the first resolution assessment.

Spreader Design for FERMI@Elettra Free Electron Laser

In this note we describe a conceptual design of a part ofthe electron beam delivery system for FERMI@Elettra free electron laser(FEL) located between the end of the linac and the entrance to the FEL.This part includes the emittance diagnostic section, the electron beamswitchyard for two FELs called spreader and matching sections. The designmeets various constrains imposed by the existing and planned buildingboundaries, desire for utilization of existing equipment and demands forvarious diagnostic instruments.

Facility Updates: Fermi @ Elettra: A Free Electron Laser for EUV and Soft X-ray Radiation

Sincrotrone Trieste has received funding and has begun the final refinement of technical parameters as well as the construction of a new Free Electron Laser (FEL) called Fermi. The new light source will be located adjacent to the existing Elettra storage ring and will use the linac that presently injects electrons into this light source. The linac will shortly become fully available to the Fermi project as a new dedicated full energy injection system is also being built for Elettra. Why are VUV and X-ray FELs so important and how do they work? Most readers will know that in a bending magnet, synchrotron radiation is created by the incoherent emission of each electron as it moves in a magnetic field.

Synchronization of ELETTRA storage-ring light sources with an ultrafast CR:LISAF laser

The techniques for synchronizing ultra fast lasers to external radio frequency reference sources are well established and characterized in the literature. However, there is little data on the actual light-to-light jitter that can be achieved in different synchrotron operation modes when an external laser is locked to the storage ring master clock. Here we present first results of the synchronization of an ultra fast Cr:LiSAF laser with synchrotron radiation generated by the ELETTRA storage ring in different filling modes. In addition, data on the synchronization of the same laser with the ELETTRA FEL pulses, both in free running and Q-switching regimes, are reported. In our experiments, laser-to-RF locking was continuously monitored using built-in phase detection. The laser light to storage ring light locking was characterized by simultaneous acquisition of the two/three pulse trains by a streak camera. In addition, pulse jitter was determined by processing of the signal of fast photodiodes monitoring the different light beams.

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.