• C. Scafuri, S. Di Mitri, G. Penco
  ELETTRA, Basovizza

The electron beam transverse emittance and Twiss parameters have been measured during the commissioning of FERMI@elettra. Matching of the beam optics to the lattice transverse acceptance and beam transport was performed by means of the elegant particle tracking code; this was integrated with the Tango-server based high level software of FERMI@elettra. Matlab scripts were used as an intermediate layer between the code and the server to automate the matching procedure. The software environment, the experimental results and the comparison with the model are described in this paper.

• M. Lonza, S. Cleva, S. Di Mitri, O. Ferrando, G. Gaio, A.A. Lutman, G. Penco, L. Pivetta, G. Scalamera
  ELETTRA, Basovizza

FERMI@Elettra is a new 4th-generation light source based on a single pass free electron laser. It consists of a 1.5-GeV normal-conducting linac working at 50 Hz repetition rate and two chains of undulators where the photon beams are produced with a seeded laser multistage mechanism. A number of control loops, some of them working on a shot by shot basis, are required to stabilize the crucial parameters of the beams. For this purpose, a generalized real-time framework integrated in the control system has been designed to flexibly and easily implement feedback loops using several monitoring and control variables. The paper discusses the requirements of the control loops and the implementation of the feedback framework. The first closed loop results and the experience gained in the operation of the feedbacks during the first phase of the machine commissioning will also be presented.

• G. Penco, E. Allaria, L. Badano, S. Bassanese, M. Bossi, D. Castronovo, G. Ciani, S. Cleva, P. Craievich, M.B. Danailov, R. De Monte, G. De Ninno, A.A. Demidovich, S. Di Mitri, M. Ferianis, O. Ferrando, S. Ferry, L. Froehlich, G. Gaio, R. Ivanov, M. Lonza, A.A. Lutman, S.V. Milton, M. Petronio, M. Predonzani, F. Rossi, L. Rumiz, C. Scafuri, G. Scalamera, P. Sigalotti, S. Spampinati, C. Spezzani, M. Trovò, M. Veronese
  ELETTRA, Basovizza
• L. Pavlovič
  Uni LJ, Ljubljana

The FERMI@Elettra injector, comprised of a high-gradient, s-band, photo-cathode rf gun, the PC gun driven laser, the first two accelerating sections, controls, and suite of diagnostics has been commissioned in 2009. The electron beam has been characterized in terms of charge, energy, energy spread and transverse emittance, and results are provided in this paper. In early 2010 linac commissioning up to 250MeV continued, and by using the RF deflecting cavity, the slice parameters of the beam have been measured. Moreover, studies on the laser pulse shaping and the relative optimization of the longitudinal ramp profile required by the nominal bunch configuration are presented in this paper.

Slides

• M.M. El-Ashmawy, G. D'Auria, S. Di Mitri
  ELETTRA, Basovizza

The 4th Generation Light Source FERMI@ELETTRA, in construction at the ELETTRA Laboratory in Trieste, requires very short electron bunches at the entrance of the undulator chain. To linearize the longitudinal phase space in the presence of the compression process, a 4th harmonic decelerating section (11992 MHz) will be installed before the first magnetic chicane. An X-band structure, with integrated alignment monitors [1], is currently under development in the framework of collaboration between CERN-PSI-ELETTRA. In this paper we will present a full longitudinal and transversal beam dynamics of the electron beam along the X-band structure during linearization process using 3D space charge code TStep [2]. Beam dynamics simulations will also be continued along the whole FERMI linac using elegant code [3].