FEL2014 - List of Authors (Ferrari, E.)

Paper

Title

Page

MOP073

Chirped Pulse Amplification in a Seeded Free-electron Laser: Design of a Test Experiment at FERMI

G. De Ninno, E. Allaria, I. Cudin, M.B. Danailov, A.A. Demidovich, S. Di Mitri, E. Ferrari, D. Gauthier, L. Giannessi, N. Mahne, G. Penco, L. Raimondi, P. Rebernik Ribič, C. Spezzani, L. Sturari, C. Svetina, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
H. Dacasa, B. Mahieu, P. Zeitoun
LOA, Palaiseau, France
M. Fajardo
IPFN, Lisbon, Portugal
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy
F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
D. Gauthier
University of Nova Gorica, Nova Gorica, Slovenia
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy

In solid-state lasers, frequency chirping is employed to stretch a short pulse prior to amplification, mitigating the problems related to high power in the active medium. After amplification, the chirp is compensated in order to recover short pulse duration and, hence, high peak power. Chirped pulse amplification (CPA) in seeded FEL’s relies on a similar principle: the seed pulse is stretched in time before interacting with the electron beam. This permits one to create bunching on a larger number of electrons, and to (approximately) linearly increase the output energy of the generated FEL pulse. In ideal conditions, the chirp carried by the phase of the seed pulse is transmitted to the output phase of the FEL pulse. Chirp compensation after the last undulator allows production of a short (ideally Fourier-transformed) pulse and, therefore, a larger peak power with respect to what obtained, for the same conditions, in standard (i.e., no-chirp-on-the-seed) operation mode. In this paper, we present the preparatory studies (i.e., numerical simulations and compressor design), which have been carried out at FERMI, in view of performing the first test experiment of CPA on a seeded FEL.

MOP077

Measurements of the FEL-bandwidth Scaling with Harmonic Number in a HGHG FEL

227

E. Allaria, M.B. Danailov, W.M. Fawley, E. Ferrari, L. Giannessi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy

In this work we report recent measurements done at FERMI showing the dependence of the FEL bandwidth with respect to the seed laser harmonic at which the FEL is operated. Comparison of FEL spectra for different Fourier-limit seed and chirp pulses is also reported.

TUB02

Generation of Intense XVUV Pulses with an Optical Klystron Enhanced Self- amplified Spontaneous Emission Free Electron Laser

332

G. Penco, E. Allaria, G. De Ninno, E. Ferrari, L. Giannessi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. De Ninno
University of Nova Gorica, Nova Gorica, Slovenia
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy

Fermi is a seeded FEL operating in high gain harmonic generation mode. The FEL layout is constituted by a modulator and six radiators separated by a dispersive section. The modulator and the radiators can be tuned to the same resonant frequency to set up an asymmetric optical klystron configuration where self amplified spontaneous emission can be generated and studied. This paper presents the experiment consisting in the analysis of the enhancement of the self-amplified spontaneous emission (SASE) radiation by the dispersion in the optical klystron. The FEL pulses produced with the optical klystron configuration are several order of magnitude more intense than in pure SASE mode with the dispersion set to zero, The experimental observations are in good agreement with simulation results and theoretical expectations. A comparison with the typical high-gain harmonic generation seeded Fel operation is also provided.

Slides TUB02 [12.835 MB]

TUP085

FERMI Status Report

564

M. Svandrlik, E. Allaria, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, M. Coreno, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, E. Ferrari, P. Finetti, L. Fröhlich, P. Furlan Radivo, G. Gaio, D. Gauthier, F. Gelmetti, L. Giannessi, M. Kiskinova, S. Krecic, M. Lonza, N. Mahne, C. Masciovecchio, M. Milloch, F. Parmigiani, G. Penco, L. Pivetta, O. Plekan, M. Predonzani, E. Principi, L. Raimondi, P. Rebernik Ribič, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Zangrando, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

FERMI, the seeded FEL located at the Elettra laboratory in Trieste, Italy, is now in regular operation for users with its first FEL line, FEL-1, which covers the wavelength range between 100 and 20 nm. We will give an overview of the typical operating modes of the facility for users and we will report on the status of beamlines and experimental stations. Three beamlines are now opened for users, three more are in construction. Meanwhile, the second FEL line of FERMI, FEL-2, a HGHG double stage cascade covering the wavelength range 20 to 4 nm is still under commissioning; we will report on the latest results in particular at the shortest wavelength, 4 nm in the fundamental.

THA02

Experimental Characterization of FEL Polarization Control with Cross Polarized Undulators

644

E. Ferrari, E. Allaria, G. De Ninno, B. Diviacco, D. Gauthier, L. Giannessi, G. Penco, C. Spezzani
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
J. Buck, M. Ilchen
XFEL. EU, Hamburg, Germany
G. De Ninno, D. Gauthier
University of Nova Gorica, Nova Gorica, Slovenia
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy
Z. Huang, A.A. Lutman
SLAC, Menlo Park, California, USA
G. Lambert, B. Mahieu
LOA, Palaiseau, France
J. Viefhaus
DESY, Hamburg, Germany

Polarization control of the coherent radiation is becoming an important feature of recent and future short wavelength free electron laser facilities. While polarization tuning can be achieved taking advantage of specially designed undulators, a scheme based on two consecutive undulators emitting orthogonally polarized fields has also been proposed. Developed initially in synchrotron radiation sources, crossed polarized undulator schemes could benefit from the coherent emission that characterize FELs. In this work we report the first detailed experimental characterization of the polarization properties of an FEL operated with crossed polarized undulators in the Soft-X-Rays. Aspects concerning the average degree of polarization and the shot to shot stability are investigated together with a comparison of the performance of various schemes to control and switch the polarization

Slides THA02 [5.383 MB]

THP070

A Tool for Real Time Acquisitions and Correlation Studies at FERMI

898

E. Allaria, W.M. Fawley, E. Ferrari
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy

In this work we report the recent implementation of a Matlab based acquisition program that, exploiting the real time capabilities of TANGO, can be used at FERMI for acquiring various machine parameter and electron beam properties together with most FEL signals. Analysis of the saved datafiles is performed with a second code that allows to retrieve correlations and to study dependence of FEL properties on machine parameters. An overview of the two codes is reported.