ELETTRA, Basovizza, Italy
FERMI@Elettra is a single-pass Free Electron Laser (FEL) user-facility covering the wavelength range from 100 nm to 4 nm. The facility is located in Trieste, Italy, nearby the third-generation synchrotron light source Elettra. Three experimental stations, dedicated to different scientific areas, have been installed installed in 2011: Low Density Matter (LDM), Elastic and Inelastic Scattering (EIS) and Diffraction and Projection Imaging (DiProI). The experiment control and data acquisition system is the natural extension of the machine control system. It integrates a shot-by-shot data acquisition framework with a centralized data storage and analysis system. Low-level applications for data acquisition and online processing have been developed using the Tango framework on Linux platforms. High-level experimental applications can be developed on both Linux and Windows platforms using C/C++, Python, LabView, IDL or Matlab. The Elettra scientific computing portal allows remote access to the experiment and to the data storage system.
ELETTRA, Basovizza, Italy
FERMI@Elettra is a Free Electron Laser (FEL) based on a 1.5 GeV linac. The pulsed operation of the accelerator and the necessity to characterize and control each electron bunch requires synchronous acquisition of the beam diagnostics together with the ability to drive actuators in real-time at the linac repetition rate. The Adeos/Xenomai real-time extensions have been adopted in order to add real-time capabilities to the Linux based control system computers running the Tango software. A software communication protocol based on gigabit Ethernet and known as Network Reflective Memory (NRM) has been developed to implement a shared memory across the whole control system, allowing computers to communicate in real-time. The NRM architecture, the real-time performance and the integration in the control system are described.
ELETTRA, Basovizza, Italy
FERMI@Elettra is a new 4th-generation light source based on a single pass Free Electron Laser (FEL). In order to ensure the feasibility of the free electron lasing and the quality of the produced photon beam, a high degree of stability is required for the main parameters of the electron beam. For this reason a flexible real-time feedback framework integrated in the control system has been developed. The first implemented bunch-by-bunch feedback loop controls the beam trajectory. The measurements of the beam position and the corrector magnet settings are synchronized to the 50 Hz linac repetition rate by means of the real-time framework. The feedback system implementation, the control algorithms and preliminary close loop results are presented.
ELETTRA, Basovizza, Italy
FERMI@Elettra is a new 4th-generation light source based on a seeded Free Electron Laser (FEL) presently under commissioning in Trieste, Italy. It is the first seeded FEL in the world designed to produce fundamental output wavelength down to 4 nm with High Gain Harmonic Generation (HGHG). Unlike storage ring based synchrotron light sources that are well known machines, the commissioning of a new-concept FEL is a complex and time consuming process consisting in thorough testing, understanding and optimization, in which a reliable and powerful control system is mandatory. In particular, integrated shot-by-shot beam manipulation capabilities and easy to use high level applications are crucial to allow an effective and smooth machine commissioning. The paper reports the status of the control system and the experience gained in two years of alternating construction and commissioning phases.