Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
Studio di Ingegneria Giorgio Marega, Trieste, Italy
FERMI@Elettra is a Free Electron Laser (FEL) users facility based on a 1.5 GeV electron linac. The personnel safety systems allow entering the restricted areas of the facility only when safety conditions are fulfilled, and set the machine to a safe condition in case any dangerous situation is detected. Hazards are associated with accelerated electron beams and with an infrared laser used for pump-probe experiments. The safety systems are based on PLCs providing redundant logic in a fail-safe configuration. They make use of a distributed architecture based on fieldbus technology and communicate with the control system via Ethernet interfaces. The paper describes the architecture, the operational modes and the procedures that have been implemented. The experience gained in the recent operation is also reported.
FHI, Berlin, Germany
HZB, Berlin, Germany
AES, Princeton, New Jersey, USA
* W. Schöllkopf et al., FIRST LASING OF THE IR FEL AT THE FRITZ-HABER-INSTITUT, BERLIN, Conference FEL12
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
FERMI is a users facility based on a seeded Free Electron Laser (FEL). A unique feature of FERMI in this new class of light sources is the tunability of the emitted photon beam both in terms of wavelength and polarization. Tuning is obtained by choosing the appropriate gap and phasing of the undulators in the chain and by opportunely setting the seed laser wavelength. A series of adjustments are then necessary in order to keep constant the machine parameters and optimize the radiation characteristics. We have developed a software application, named SuperGap, which does all the calculations and coordinates the operations required to set the desired wavelength and polarization. SuperGap allows operators to perform this procedure in seconds. The speed and accuracy of the wavelength change have been largely exploited during user dedicated shifts to perform various types of scans in the experimental stations. The paper describes the algorithms and numerical techniques used by SuperGap and its architecture based on the Tango control system.
PSI, Villigen PSI, Switzerland
ANL, Argonne, USA
CARS, Argonne, Ilinois, USA
[1] Krempaský et al, ICALEPCS 2001
[2] www.aps.anl.gov/bcda/synApps/index.php
[3] M. Rivers, SRI 2009, Melbourne
[4] B. Kalantari et al, ICALEPCS 2011
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
Evolution of the FERMI@Elettra Beam Based Feedbacks FERMI@Elettra is the first seeded Free Electron Laser (FEL) users facility. A number of shot-to-shot feedback loops running synchronously at the machine repetition rate stabilize the electron beam trajectory, energy and bunch length, as well as the trajectory of the laser beams used for the seeding and pump-probe experiments. They are based on a flexible real-time distributed framework integrated into the control system. The interdependence between feedback loops and the need to react coordinately to different operating conditions lead to the development of a real-time supervisor capable of controlling each loop depending on critical machine parameters not directly involved in the feedbacks. The overall system architecture, performance and user interfaces are presented.
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
After installation and commissioning, the Free Electron Laser facility FERMI is now open to users. As of December 2012, three experimental stations dedicated to different scientific areas, are available for user research proposals: Low Density Matter (LDM), Elastic & Inelastic Scattering (EIS), and Diffraction & Projection Imaging (DiProI). A flexible and highly configurable common framework has been developed and successfully deployed for experiment management and shot-by-shot data acquisition. This paper describes the software architecture behind all the experiments performed so far; the combination of the EXECUTER script engine with a specialized data acquisition device (FERMIDAQ) based on TANGO. Finally, experimental applications, performance results and future developments are presented and discussed.
