| Paper |
Title |
Page |
| TUBAU04 |
Generation of Sub-fsec, High Brightness Electron Beams for Single Spike SASE FEL Operation
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214 |
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- J. B. Rosenzweig, M. P. Dunning, L. Faillace, A. Fukasawa, E. Hemsing, G. Marcus, A. Marinelli, P. Musumeci, B. D. O'Shea, C. Pellegrini, S. Reiche
UCLA, Los Angeles, California
- M. Boscolo, M. Ferrario, L. Palumbo, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma)
- L. Giannessi, C. Ronsivalle
ENEA C. R. Frascati, Frascati (Roma)
- V. Petrillo
Istituto Nazionale di Fisica Nucleare, Milano
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We present here the theory and computational modeling of beams in a new regime, where <1 pC beams are strongly velocity bunched at low energy, and then compressed at several GeV to less than a fsec. This regime of operation produces beams with thermally dominated transverse emittance, and mitigates many problems associated with the nC-level operation. These problems include CSR induced instability and intra-undulator wakes. The resulting beams have extremely high brightness, enabling very high gain, efficiency, and single spike operation. We present the scaling laws governing this regime, and the detailed example of the proposed SPARX FEL design.
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| TUPPH012 |
Single spike experiments with the SPARC SASE FEL
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258 |
| |
- M. Ferrario, M. Boscolo, L. Palumbo, C. Vaccarezza
INFN/LNF, Frascati (Roma)
- G. Andonian, E. Hemsing, G. Marcus, S. Reiche, J. B. Rosenzweig
UCLA, Los Angeles, California
- A. Bacci, I. Boscolo, F. Castelli, S. Cialdi, V. Petrillo, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano
- L. Giannessi, C. Ronsivalle
ENEA C. R. Frascati, Frascati (Roma)
- M. Serluca
INFN-Roma, Roma
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We describe in this paper a possible experiment with the existing SPARC photoinjector to test the generation of sub-picosecond high brightness electron bunches able to produce single spike radiation pulses at 500 nm with the SPARC self-amplified spontaneous emission free-electron laser (SASE-FEL). The main purpose of the experiment will be the production of short electron bunches as long as few SASE cooperation lengths and to validate scaling laws to foresee operation at shorter wavelength in the future operation with SPARX. We present in this paper start to end simulations of the expected FEL performance and discuss the layout of the machine, including the diagnostics to measure the FEL pulse length and other aspects of FEL performance. The experience gained from this experiment, will help in the configuration of the VUV and X-ray FEL SPARX to obtain FEL pulses below 10 fs.
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| TUPPH018 |
Longitudinal Diagnostic for Single-Spike SASE FEL Operation
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274 |
| |
- G. Marcus, G. Andonian, A. Fukasawa, S. Reiche, J. B. Rosenzweig
UCLA, Los Angeles, California
- M. Ferrario, L. Palumbo
INFN/LNF, Frascati (Roma)
- L. Giannessi
ENEA C. R. Frascati, Frascati (Roma)
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The possibility of ultra-short beam, very low charge, short wavelength FELs at SPARC has been recently investigated. This paper explores the development of a longitudinal diagnostic that will provide the capability to characterize the short wavelength radiation based on the Frequency Resolved Optical Gating (FROG) technique. The paper includes studies of pulses simulated for the SPARC case using GENESIS and reconstructed using the FROG algorithm as well as proposed experimental layouts for the device.
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| TUPPH023 |
Quasicrystalline Beam Formation in RF Photoinjectors
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285 |
| |
- J. B. Rosenzweig, M. P. Dunning, E. Hemsing, G. Marcus, A. Marinelli, P. Musumeci
UCLA, Los Angeles, California
- M. Ferrario
INFN/LNF, Frascati (Roma)
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The recent observation of coherent optical transition radiation from the beam after the injector line at the LCLS has raised serious questions concerning the present model of beam dynamics in RF photoinjectors. We present here an analysis of what we term quasicrystalline beam formation. In this scenario, the relatively low longitudinal temperature, in combination with strong acceleration and, finally, temporal rearrangement due to bending, allows the longitudinal beam dimension to become more regular, on the microscopic scale of optical wavelengths, than expected from equilibrium statistical properties. This beam distribution then may then display a strong degree of coherence in its optical transition radiation output. We discuss further experimental investigations of this phenomenon.
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| TUPPH048 |
Recent Results of the SPARC Project
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359 |
| |
- M. Ferrario, D. Alesini, M. Bellaveglia, R. Boni, M. Boscolo, M. Castellano, E. Chiadroni, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, A. Marcelli, B. Marchetti, M. Migliorati, A. Mostacci, E. Pace, L. Palumbo, L. Pellegrino, R. Ricci, U. Rotundo, C. Sanelli, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario
INFN/LNF, Frascati (Roma)
- A. Bacci, I. Boscolo, F. Broggi, F. Castelli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, A. R. Rossi, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano
- M. Bougeard, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Salieres, O. Tchebakoff
CEA, Gif-sur-Yvette
- L. Catani
INFN-Roma II, Roma
- A. Cianchi
Università di Roma II Tor Vergata, Roma
- F. Ciocci, G. Dattoli, M. Del Franco, A. Dipace, A. Doria, G. P. Gallerano, L. Giannessi, E. Giovenale, G. L. Orlandi, S. Pagnutti, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I. P. Spassovsky, V. Surrenti
ENEA C. R. Frascati, Frascati (Roma)
- M.-E. Couprie
SOLEIL, Gif-sur-Yvette
- A. Marinelli, J. B. Rosenzweig
UCLA, Los Angeles, California
- M. Mattioli, M. Petrarca, M. Serluca
INFN-Roma, Roma
- J. Rossbach
Uni HH, Hamburg
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The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive 500 nm FEL experiments in various configurations. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. The second stage of the commissioning, that is currently underway, foresees a detailed analysis of the beam matching with the linac in order to confirm the theoretically prediction of emittance compensation based on the “invariant envelope” matching , the demonstration of the “velocity bunching” technique in the linac and the characterisation of the spontaneous emission radiation in the SPARC undulators. In this paper we report the experimental results obtained so far.
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