| Paper |
Title |
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| MOPCH030 |
Production of Coherent X-rays with a Free Electron Laser Based on an Optical Wiggler
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113 |
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- V. Petrillo, A. Colzato
Universita' degli Studi di Milano, Milano
- A. Bacci, C. Maroli, L. Serafini
INFN-Milano, Milano
- M. Ferrario
INFN/LNF, Frascati (Roma)
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The interaction between high-brightness electron beams and counter-propagating laser pulses produces X rays via Thomson scattering. If the laser source is long enough, the electrons bunch on the scale of the emitted X-ray wavelength and a regime of collective effects establishes. In this case, the FEL instability develops and the system behaves like a FEL based on an optical undulator. Coherent X-rays are irradiated, with a bandwidth thinner than that of the incoherent emission. The emittance of the beam and gradients or irregularities in the laser energy distribution are the principal factors that limit the growth of the X-ray signal. We analyse with a 3-D code the transverse effects in the emission produced by a relativistic electron beam when it is under the action of an optical laser pulse and the X-ray spectra obtained. The scalings typical of the optical wiggler, with very short gain lengths and overall time durations of the process make possible considerable emission also in violation of the Pellegrini criterion for static wigglers. A generalized form of this criterion is validated on the basis of the numerical evidence.
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| MOPCH024 |
Future Seeding Experiments at SPARC
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95 |
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- L. Giannessi, S. Ambrogio, F. Ciocci, G. Dattoli, A. Doria, G.P. Gallerano, E. Giovenale, M. Quattromini, A. Renieri, C. Ronsivalle, I.P. Spassovsky
ENEA C.R. Frascati, Frascati (Roma)
- D. Alesini, M.E. Biagini, R. Boni, M. Castellano, A. Clozza, A. Drago, M. Ferrario, V. Fusco, A. Gallo, A. Ghigo, M. Migliorati, L. Palumbo, C. Sanelli, F. Sgamma, B. Spataro, S. Tomassini, C. Vaccarezza, C. Vicario
INFN/LNF, Frascati (Roma)
- M. Bougeard, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Salieres, O. Tcherbakoff
CEA, Gif-sur-Yvette
- M.-E. Couprie
SOLEIL, Gif-sur-Yvette
- A. Dipace, E. Sabia
ENEA Portici, Portici (Napoli)
- M. Mattioli, P. Musumeci, M. Petrarca
Università di Roma I La Sapienza, Roma
- M. Nisoli, G. Sansone, S. Stagira, S. de Silvestri
Politecnico/Milano, Milano
- L. P. Poletto, G. T. Tondello
Univ. degli Studi di Padova, Padova
- L. Serafini
INFN-Milano, Milano
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Sources based on High order Harmonics Generated in gases (HHG) with high power Ti:Sa lasers pulses represent promising candidates as seed for FEL amplifiers for several reasons, as spatial and temporal coherence, wavelength tunability and spectral range, which extends down to the nm wavelength scale. This communication describes the research work plan that is under implementation at the SPARC FEL facility in the framework of the EUROFEL programme. The main goal of the collaboration is to study and test the amplification and the FEL harmonic generation process of an input seed signal obtained as higher order harmonics generated both in crystals (400 nm and 266 nm) and in gases (266 nm, 160 nm, 114 nm). The SPARC FEL can be configured to test several cascaded FEL layouts that will be analysed in this contribution.
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| MOPCH028 |
Status of the SPARX FEL Project
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107 |
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- C. Vaccarezza, D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, D. Filippetto, V. Fusco, A. Gallo, A. Ghigo, S. Guiducci, M. Migliorati, L. Palumbo, L. Pellegrino, M.A. Preger, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stella, F. Tazzioli, M. Vescovi, C. Vicario
INFN/LNF, Frascati (Roma)
- F. Alessandria, A. Bacci, F. Broggi, C. De Martinis, D. Giove, M. Mauri
INFN/LASA, Segrate (MI)
- L. Catani, E. Chiadroni, A. Cianchi, C. Schaerf
INFN-Roma II, Roma
- S. Cialdi, C. Maroli, V. Petrillo, M. Rome, L. Serafini
INFN-Milano, Milano
- F. Ciocci, G. Dattoli, A. Doria, F. Flora, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P.L. Ottaviani, G. Parisi, L. Picardi, M. Quattromini, A. Renieri, C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma)
- P. Emma
SLAC, Menlo Park, California
- L. Ficcadenti, A. Mostacci
Rome University La Sapienza, Roma
- M. Mattioli
Università di Roma I La Sapienza, Roma
- P. Musumeci
INFN-Roma, Roma
- S. Reiche, J.B. Rosenzweig
UCLA, Los Angeles, California
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The SPARX project consists in an X-ray-FEL facility jointly supported by MIUR (Research Department of Italian Government), Regione Lazio, CNR, ENEA, INFN and Rome University Tor Vergata. It is the natural extension of the ongoing activities of the SPARC collaboration. The aim is the generation of electron beams characterized by ultra-high peak brightness at the energy of 1 and 2 GeV, for the first and the second phase respectively. The beam is expected to drive a single pass FEL experiment in the range of 13.5-6 nm and 6-1.5 nm, at 1 GeV and 2 GeV respectively, both in SASE and SEEDED FEL configurations. A hybrid scheme of RF and magnetic compression will be adopted, based on the expertise achieved at the SPARC high brightness photoinjector presently under commissioning at Frascati INFN-LNF Laboratories. The use of superconducting and exotic undulator sections will be also exploited. In this paper we report the progress of the collaboration together with start to end simulation results based on a combined scheme of RF compression techniques.
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| MOPCH029 |
Status of the SPARC Project
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110 |
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- P. Musumeci, D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca
Università di Roma I La Sapienza, Roma
- D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario
INFN/LNF, Frascati (Roma)
- F. Alessandria, A. Bacci, I. Boscolo, F. Broggi, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, M. Mauri, V. Petrillo, M. Rome, A.R. Rossi, L. Serafini
INFN-Milano, Milano
- L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, S. Tazzari
INFN-Roma II, Roma
- F. Ciocci, G. Dattoli, A. Dipace, A. Doria, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P.L. Ottaviani, S. Pagnutti, L. Picardi, M. Quattromini, A. Renieri, G. Ronci, C. Ronsivalle, M. Rosetti, E. Sabia, M. Sassi, A. Torre, A. Zucchini
ENEA C.R. Frascati, Frascati (Roma)
- A. Perrone
INFN-Lecce, Lecce
- S. Reiche, J.B. Rosenzweig, G. Travish
UCLA, Los Angeles, California
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The SPARC Project is starting the commissioning of its photo-injector. RF gun, RF sources, RF network and control, power supplies, emittance meter, beam diagnostics and control to measure the RF gun beam are installed. The photocathode drive laser has been characterized in terms of pulse shape and quality. We expect to conduct beam measurements at RF gun exit in the next future and consequently to start the installation of accelerating sections. The design of the 12 m undulator for the FEL experiment has been completed and the first undulator section out of 6 is under construction: we expect to characterize it at Frascati ENEA laboratory within the next months. SPARC as a facility will host FEL experiments using SASE, seeding and non-linear resonant harmonics. Additional R&D on X-band and S-band structures for velocity bunching are in progress, as well as studies on new photocathode materials and exotic undulator designs. We also present studies on solenoid field defects, beam based alignments, exotic electron bunch production (blow-out of short laser pulses or intensity modulated laser pulses). The possible use of segmented superconducting micro-undulators will be discussed too.
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| WEPCH127 |
Analysis of Radiative Effects in the Electron Emission from the Photocathode and in the Acceleration inside the RF Cavity of a Photoinjector using the 3D Numerical Code RETAR
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2221 |
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- V. Petrillo, C. Maroli
Universita' degli Studi di Milano, Milano
- G. Alberti
Università degli Studi di Milano, Milano
- A. Bacci, A.R. Rossi, L. Serafini
INFN-Milano, Milano
- M. Ferrario
INFN/LNF, Frascati (Roma)
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The three-dimensional fully relativistic and self-consistent code RETAR has been developed to model the dynamics of high-brightness electron beams and in particular to assess the importance of the retarded radiative part of the emitted electromagnetic fields in all conditions where the electrons experience strong accelerations. In this analysis we evaluate the radiative energy losses in the electron emission process from the photocathode of an injector, during the successive acceleration of the electron beam in the RF cavity and the focalization due to the magnetic field of the solenoid, taking also into account the e.m. field of the laser illuminating the cathode. The analysis is specifically carried out with parameters of importance in the framework of the SPARC and PLASMONX projects.
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| WEPLS021 |
The PLASMONX Project for Advanced Beam Physics Experiments
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2439 |
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- L. Serafini, A. Bacci, R. Bonifacio, M. Cola, C. Maroli, V. Petrillo, N. Piovella, R. Pozzoli, M. Rome, A.R. Rossi, L. Volpe
INFN-Milano, Milano
- D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario
INFN/LNF, Frascati (Roma)
- F. Alessandria, F. Broggi, C. De Martinis, D. Giove, M. Mauri
INFN/LASA, Segrate (MI)
- W. Baldeschi, A. Barbini, M. Galimberti, A. Giulietti, A. Gizzi, P. Koester, L. Labate, S. Laville, A. Rossi, P. Tomassini
CNR/IPP, Pisa
- U. Bottigli, B. Golosio, P.N. Oliva, A. Poggiu, S. Stumbo
INFN-Cagliari, Monserrato (Cagliari)
- C.A. Cecchetti, D. Giulietti
UNIPI, Pisa
- D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca
Università di Roma I La Sapienza, Roma
- P. Musumeci
INFN-Roma, Roma
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The Project PLASMONX is well progressing into its design phase and has entered as well its second phase of procurements for main components. The project foresees the installation at LNF of a Ti:Sa laser system (peak power > 170 TW), synchronized to the high brightness electron beam produced by the SPARC photo-injector. The advancement of the procurement of such a laser system is reported, as well as the construction plans of a new building at LNF to host a dedicated laboratory for high intensity photon beam experiments (High Intensity Laser Laboratory). Several experiments are foreseen using this complex facility, mainly in the high gradient plasma acceleration field and in the field of mono-chromatic ultra-fast X-ray pulse generation via Thomson back-scattering. We present an innovative scheme of external injection of the SPARC beam into laser wake-field driven plasma waves. Detailed numerical simulations have been carried out to study the generation of short electron bunches, to be injected into plasma waves driven with adiabatically variable density in order to compress the bunch at injection and further accelerate it by preserving a small energy spread and good beam quality.
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| THPCH010 |
Electron Beam-laser Interaction near the Cathode in a High Brightness Photoinjector
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2805 |
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- M. Ferrario, G. Gatti
INFN/LNF, Frascati (Roma)
- J.B. Rosenzweig
UCLA, Los Angeles, California
- L. Serafini
INFN-Milano, Milano
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The production of high charge short bunches in a high brightness photoinjector requires laser pulses driving the cathode with GW range peak power on a mm spot size. The resulting transverse electric field experienced by the electron beam near the cathode is of the order of 200-500 MV/m, well in excess of a typical RF accelerating field of 50-100 MV/m. We present here an analytical and computational study of the resultant beam dynamics. Simulations including the electron beam-laser interaction have been performed with the code HOMDYN taking into account the superposition of incident and reflected laser pulses as well as space charge fields. Under this conditions the emittance degradation is negligible, as predicted by analytical methods, but a longitudinal charge modulation occurs on the scale of the laser wavelength, in case of oblique incidence, driven by the longitudinal component of the laser field. Preliminary simulations up to the photoinjector exit show that charge modulation is transformed into energy modulation via the space charge field, which may produce enhanced microbunching effects when the beam is further compressed in a magnetic chicane.
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