Rossi, A. R.

Paper	Title	Page
MOOAAB02	Experimental Results with the SPARC Emittance-meter	80
	M. Ferrario, D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, M. Migliorati, A. Mostacci, E. Pace, L. Palumbo, L. Pellegrino, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) A. Bacci, S. Cialdi, A. R. Rossi, L. Serafini INFN-Milano, Milano L. Catani, E. Chiadroni, A. Cianchi INFN-Roma II, Roma A. M. Cook, M. P. Dunning, P. Frigola, J. B. Rosenzweig UCLA, Los Angeles, California L. Giannessi, M. Quattromini, C. Ronsivalle ENEA C. R. Frascati, Frascati (Roma) P. Musumeci, M. Petrarca INFN-Roma, Roma
	The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive a SASE-FEL in the visible light. As a first stage of the commissioning a complete characterization of the photoinjector has been done with a detailed study of the emittance compensation process downstream the gun-solenoid system. For this purpose a novel beam diagnostic device, called emittance meter, has been developed and used at SPARC. This device has allowed to measure the evolution of beam sizes, energy spread and rms transverse emittances at different location along the beamline, in the region where space-charge effects dominate the electron dynamics and the emittance compensation process takes place. In this paper we report our commissioning experience and the results obtained. In particular a comparison between the performances of a Gaussian laser pulse versus a Flat Top laser pulse will be discussed. We report also the first experimental observation of the double emittance minima effect on which is based the optimised matching with the SPARC linac.
	Slides
TUPMN041	Three Dimensional Analysis of the X-Radiation Produced by a Collective Thomson Source	1007
	V. Petrillo Universita' degli Studi di Milano, Milano A. Bacci, C. Maroli, A. R. Rossi, L. Serafini, P. Tomassini INFN-Milano, Milano A. Colzato Universita degli Studi di Milano, Milano
	A set of 3-D equations that describes the collective head to head interaction between a laser pulse and a relativistic electron beam is presented and solved. The relevant dispersion relation is studied, as well as the gain properties of the system. The FEL instability dominates the radiation process. The radiation emitted is characterized by short wavelength, thin spectrum and high coherence. The most important three-dimensional effects are the emittance of the beam and the transverse distribution of the laser energy. The production of radiation wavelengths of 12 nm, 1nm, and 1 Angstron are presented.
TUPMN034	Comparison Between SPARC E-Meter Measurements and Simulations	986
	C. Ronsivalle, L. Giannessi, M. Quattromini ENEA C. R. Frascati, Frascati (Roma) A. Bacci, A. R. Rossi, L. Serafini INFN-Milano, Milano M. Boscolo, E. Chiadroni, M. Ferrario, D. Filippetto, V. Fusco, G. Gatti, M. Migliorati, A. Mostacci, C. Vaccarezza, C. Vicario INFN/LNF, Frascati (Roma) A. Cianchi INFN-Roma II, Roma M. Petrarca Universita di Roma I La Sapienza, Roma
	For the SPARC photoinjector commissioning the emittance compensation process has been studied experimentally under different beam conditions (variation of charge, spot size, beam shape…) by a novel device called "emittance-meter", consisting in a movable emittance measurement system based on the 1D pepper pot method scanning a region 1.2 m long downstream the RF-gun. The results of a detailed comparison between the measurements and beam dynamics simulations performed by the different codes(PARMELA, HOMDYN, TREDI) employed for SPARC design are presented and discussed here.
TUPMN039	Status of the SPARC-X Project	1001
	C. Vaccarezza, 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, C. Ligi, M. Migliorati, A. Mostacci, E. Pace, L. Palumbo, L. Pellegrino, M. A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stella, F. Tazzioli, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, A. Bacci, R. Bonifacio, I. Boscolo, F. Broggi, F. Castelli, S. Cialdi, C. De Martinis, A. F. Flacco, D. Giove, C. Maroli, V. Petrillo, A. R. Rossi, L. Serafini INFN-Milano, Milano M. Bougeard, P. Breger, B. Carre, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Monchicourt, P. Salieres, O. Tcherbakoff CEA, Gif-sur-Yvette L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, C. Schaerf INFN-Roma II, Roma F. Ciocci, G. Dattoli, A. Dipace, A. Doria, F. Flora, G. P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P. L. Ottaviani, S. Pagnutti, G. Parisi, 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) M.-E. Couprie SOLEIL, Gif-sur-Yvette P. Emma SLAC, Menlo Park, California M. Mattioli, D. Pelliccia Universita di Roma I La Sapienza, Roma P. Musumeci, M. Petrarca INFN-Roma, Roma C. Pellegrini, S. Reiche, J. B. Rosenzweig UCLA, Los Angeles, California A. Perrone INFN-Lecce, Lecce
	SPARC-X is a two branch project consisting in the SPARC test facility dedicated to the development and test of critical subsystems such as high brightness photoinjector and a modular expandable undulator for SASE-FEL experiments at 500 nm with seeding, and the SPARX facility aiming at generation of high brightness coherent radiation in the 3-13 nm range, based on the achieved expertise. The projects are supported by MIUR (Research Department of Italian Government) and Regione Lazio. SPARC has completed the commissioning phase of the photoinjector in November 2006. The achieved experimental results are here summarized together with the status of the second phase commissioning plans. The SPARX project is based on the generation of ultrahigh peak brightness electron beams at the energy of 1 and 2 GeV generating radiation in the 3-13 nm range. The construction is at the moment planned in two steps starting with a 1 GeV Linac. The project layout including both RF-compression and magnetic chicane techniques has been studied and compared, together with the feasibility of a mixed s-band and x-band linac option.
THPAN031	Optimization of the Beam Line Characteristics by Means of a Genetic Algorithm	3295
	A. Bacci, A. R. Rossi, L. Serafini INFN-Milano, Milano V. Petrillo Universita' degli Studi di Milano, Milano
	The optimization of the optics in a LINAC requires a very demanding tuning of the involved parameters, particularly in the case of high brightness electron beams applied to the production of X-ray in a Thomson back-scattering source. The relationship between the parameters is non-linear and it is not possible to treat them as independent variables, causing the impossibility of setting them handily. A genetic algorithm is a powerful tool able to circumvent this difficulty. We have applied the genetic algorithm to the case of the SPARC beam line.
THPAN032	Study of the Beam Dynamics in a Linac with the Code RETAR	3298
	A. R. Rossi, A. Bacci, C. Maroli, L. Serafini INFN-Milano, Milano V. Petrillo Universita' degli Studi di Milano, Milano
	The three-dimensional fully relativistic and self-consistent code RETAR has been applied 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 and the inhomogeneities on the cathode surface. The analysis is specifically carried out with parameters of importance in the framework of the SPARC and PLASMONX projects.