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WEOB3 |
Seeding Experiments at SPARC |
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- M. Labat, F. Briquez, M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France
- D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
- A. Bacci, V. Petrillo, A.R. Rossi, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
- M. Bougeard, B. Carré, D. Garzella
CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
- A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
- F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
- L. Cultrera
CLASSE, Ithaca, New York, USA
- D. Filippetto
LBNL, Berkeley, California, USA
- F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
- G. Lambert
LOA, Palaiseau, France
- G. Marcus, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
- M. Migliorati, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
- J.V. Rau
ISM-CNR, Rome, Italy
- M. Serluca
INFN-Roma, Roma, Italy
- C. Vicario
PSI, Villigen PSI, Switzerland
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The SPARC FEL amplifier has been configured as a single stage HGHG FEL with a modulator and a radiator operating at the second harmonic. The HGHG cascade has been seeded with harmonics generated in a gas cell where a Ti:Sa laser pulse of 120 fs of duration is converted into higher harmonics. The cascaded FEL configuration obtained by tuning the undulator gaps has been studied by varying the number of modulators and radiators to optimize the conversion efficiency. The process of harmonic generation in a free electron laser operating in superradiant regime has been also analysed. Harmonic generation is expected to be efficient because of the quasi steady-state distribution of the e-beam phase space predicted in this regime. Harmonics up to the 11th have been experimentally observed.
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Slides WEOB3 [5.198 MB]
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WEOCI2 |
Ultrashort Single Spike Pulse Generation at the SPARC Test Facility |
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- D. Filippetto
LBNL, Berkeley, California, USA
- A. Bacci, M. Bellaveglia, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, E. Pace, B. Spataro, C. Vaccarezza, C. Vicario
INFN/LNF, Frascati (Roma), Italy
- A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
- F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
- F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
- M. Moreno, M. Serluca
INFN-Roma, Roma, Italy
- A. Mostacci
Rome University La Sapienza, Roma, Italy
- V. Petrillo, A.R. Rossi
Istituto Nazionale di Fisica Nucleare, Milano, Italy
- J.V. Rau, V. Rossi Albertini
ISM-CNR, Rome, Italy
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We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a Self Amplified Spontaneous Emission mode Free Electron Laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. Longitudinal phase space rotation via velocity bunching is used to generate the energy chirp, which also increases the peak current and the FEL performances. An increase of more than one order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.
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Slides WEOCI2 [16.008 MB]
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| THOB2 |
Advanced Beam Dynamics Experiments at SPARC |
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- A. Bacci, D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
- A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
- M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
- S. Lupi
Coherentia, Naples, Italy
- B. Marchetti
INFN-Roma II, Roma, Italy
- A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
- V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
- L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
- M. Serluca
INFN-Roma, Roma, Italy
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The successful operation of the SPARC injector in the Velocity Bunching (VB) mode (bunches with 1 kA current with emittance of 3 mm-mrad have been produced) has opened new perspectives to conduct advanced beam dynamics experiments with ultra-short electron pulses able to extend the THz spectrum or to drive the FEL in the SASE Single Spike mode. A new technique called Laser Comb, able to generate a train of short pulses with high repetition rate, has been extensively tested in the VB configuration. Two electron beam pulses 300 fs long separated by 1 ps have been characterized and the spectrum produced by the SASE interaction has been observed, showing that both pulses have been correctly matched to the undulator and were both lasing. In this paper we report the experimental and theoretical results obtained so far.
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Slides THOB2 [6.673 MB]
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