Alesini, D.

Paper	Title	Page
MOPC068	Preliminary Characterization of the Beam Properties of the SPARC Photoinjector	226
	A. Cianchi INFN-Roma II, Roma D. Alesini, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, G. Gatti, B. Marchetti, E. Pace, C. Vaccarezza, C. Vicario INFN/LNF, Frascati (Roma) A. Mostacci Rome University La Sapienza, Roma C. Ronsivalle ENEA C. R. Frascati, Frascati (Roma)
	The SPARC photoinjector is the test prototype of the recently approved SPARX project. It is used as R&D facility to perform accurate beam dynamics studies, comparing measurements and simulations. Emittance measurements at the gun exit and at the full energy has been performed and benchmarked with the simulations.
MOPP011	Fast Vertical Beam Instability in the CTF3 Combiner Ring	574
	R. Corsini, D. Schulte, P. K. Skowronski, F. Tecker CERN, Geneva D. Alesini, C. Biscari, A. Ghigo INFN/LNF, Frascati (Roma)
	The CLIC Test Facility CTF3 is being built at CERN by an international collaboration, in order to demonstrate the main feasibility issues of the CLIC two-beam technology by 2010. The facility includes an 84 m combiner ring, which was installed and put into operation in 2007. High-current operation has shown a vertical beam break-up instability, leading to high beam losses over the four turns required for nominal operation of the CTF3 ring. Such instability is most likely due to the vertically polarized transverse mode in the RF deflectors used for beam injection and combination. In this paper we report the experimental data and compare them with simulations. Possible methods to eliminate the instability are also outlined.
TUPC072	Design and Fabrication of an X-band Traveling Wave Deflection Mode Cavity for Longitudinal Characterization of Ultra-short Electron Beam Pulses	1215
	A. Y. Murokh, R. B. Agustsson, S. Boucher, P. Frigola RadiaBeam, Marina del Rey D. Alesini INFN/LNF, Frascati (Roma) R. J. England, J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California V. Yakimenko BNL, Upton, Long Island, New York
	An X-band Traveling wave Deflector mode cavity (XTD) has been developed at Radiabeam Technologies to perform longitudinal characterization of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. An XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, fabrication procedure, and commissioning plans are presented. An experimental program at ATF to utilize the deflector for compressed beam characterization is discussed, including proposed measurements of the phase space filamentation due to non-linear processes in a chicane compressor.
TUPC080	Fermi Low-energy Transverse RF Deflector Cavity	1239
	P. Craievich, S. Biedron, C. Bontoiu, S. Di Mitri, M. Ferianis, M. Veronese ELETTRA, Basovizza, Trieste D. Alesini, L. Palumbo INFN/LNF, Frascati (Roma) L. Ficcadenti Rome University La Sapienza, Roma M. Petronio DEEI, Trieste
	The layout of FERMI@Elettra will include a transverse S-band RF deflector that will be located after the first bunch compressor (BC1) at 250 MeV. The deflector will operate in a vertical deflecting mode and coupled to a downstream dipole will be used to measure the electron bunch length and in particular to allow time-resolved beam quality measurements such as horizontal slice emittance and slice energy spread. In this paper we discuss the electron bunch deflection at 250 MeV taking into account the principal elements that dominate the selection of the transverse peak voltage specification: the finite transverse emittance, the resolution of OTR screens and the desired number of the slice divisions along the bunch that we wish to observe. The RF deflector proposed here is a frequency scaled version of the 5-cell standing wave SPARC structure.
TUPC105	Slice Emittance Measurements at SPARC Photoinjector with a RF Deflector	1305
	C. Vaccarezza, D. Alesini, E. Chiadroni, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, G. Gatti, B. Marchetti, E. Pace INFN/LNF, Frascati (Roma) A. Cianchi Università di Roma II Tor Vergata, Roma A. Mostacci Rome University La Sapienza, Roma
	The SPARC photoinjector is a R&D facility performing beam dynamics studies and driving a SASE-FEL. The RF deflector, completely designed and built by the SPARC team, allows measurements of the longitudinal properties of the beam bunch. Using it and the well know technique of the quadrupoles scan, the slice emittance has been measured in different conditions and benchmarked with the simulations.
TUPD014	Detailed Design, Manufacturing and Testing of a Strip-line Extraction Kicker for CTF3 Combiner Ring	1458
	I. Rodriguez, L. García-Tabarés, E. Rodríguez García, F. Toral CIEMAT, Madrid D. Alesini, A. Ghigo, F. Marcellini, M. Zobov INFN/LNF, Frascati (Roma) T. Fowler, I. Syratchev CERN, Geneva
	The first calculations to design the CTF3 Combiner Ring extraction kicker are reported elsewhere. The last computing step before fabrication is the wakefield analysis, to determine if the bunch disturbance is acceptable. Two different codes have been used for cross-checking: CST Particle Studio and GDFidl. The computation is challenging because of the long structure (2.4 m) with a short bunch (3 mm). Besides, both transitions are not equal, because of different straight sections of the input and output beam pipe, and then the solution method is more complex. On the other hand, the main challenges for manufacturing are the long electrodes support via ceramic stand-offs and the flexible electrical connections to allow for electrodes thermal differential displacement. Special tooling has also been developed for assembly within the required tolerances. The device has been successfully leak tested. High frequency transmission coefficients and high voltage dielectric strength were also measured.
TUPP051	Coupling Impedance of DAΦNE Upgraded Vacuum Chamber	1661
	F. Marcellini, D. Alesini, P. Raimondi, G. Sensolini, B. Spataro, A. Stella, S. Tomassini, M. Zobov INFN/LNF, Frascati (Roma)
	The DAΦNE Phi-factory at INFN LNF has been ugraded in the second half of 2007 with a scope to test a recently proposed scheme of crab waist collisions. The vacuum chamber of the collider has been substantially modified: two new low impedance interaction regions have been designed and installed, the new stripline injection kickers have been implemented, the old bellows have been substituted by the new ones and all ion clearing electrodes have been removed. In the paper we present the machine impedance study of these new vacuum chamber components and compare bunch lengthening measurements in the modified DAΦNE with simulation results.
WEXG02	Crabbed Waist Collisions in DAΦNE and Super-B Design	1898
	P. Raimondi, D. Alesini, M. E. Biagini, C. Biscari, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G. O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, F. Murtas, L. Pellegrino, M. A. Preger, L. Quintieri, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma) N. Arnaud, D. Breton, P. Roudeau, A. Stocchi, V. Variola, B. F. Viaud LAL, Orsay S. Bettoni CERN, Geneva P. Branchini roma3, Rome M. Esposito Rome University La Sapienza, Roma I. Koop, E. B. Levichev, P. A. Piminov, D. N. Shatilov, V. V. Smaluk BINP SB RAS, Novosibirsk K. Ohmi KEK, Ibaraki E. Paoloni University of Pisa and INFN, Pisa M. Schioppa INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza) D. Teytelman SLAC, Menlo Park, California P. Valente INFN-Roma, Roma
	The new idea of increasing the luminosity of a collider with crabbed waist collisions and first experimental results from DAΦNE using this concept are presented. Consequences for the design of future factories will be discussed. An outlook to the performance reach with crabbed waist collisions is given, with emphasis on future B Factories.
	Slides
WEPC075	Recent Results and Future Perspectives of the SPARC Project	2169
	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, B. Marchetti, A. Marinelli, C. Marrelli, 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 INFN-Milano, 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, 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 M. Mattioli, M. Serluca INFN-Roma, Roma M. Migliorati, A. Mostacci Rome University La Sapienza, Roma M. Petrarca Università di Roma I La Sapienza, Roma J. B. Rosenzweig UCLA, Los Angeles, California
	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, a Thomson backscattering source and a plasma accelerator experiment. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. As a first stage of the commissioning a complete characterization of the photoinjector has been accomplished with a detailed study of the emittance compensation process downstream the gun-solenoid system and the demonstration of the emittance oscillation in the drift. 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 and the demonstration of the “velocity bunching” technique in the linac. In this paper we report the experimental results obtained so far and the scientific program for the near future.
WEPP036	DAΦNE Setup and Operation with the Crab-Waist Collision Scheme	2599
	C. Milardi, D. Alesini, M. E. Biagini, C. Biscari, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G. O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, F. Murtas, L. Pellegrino, M. A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma) N. Arnaud, D. Breton, P. Roudeau, A. Stocchi, V. Variola, B. F. Viaud LAL, Orsay S. Bettoni CERN, Geneva P. Branchini roma3, Rome M. Esposito Rome University La Sapienza, Roma I. Koop, E. B. Levichev, P. A. Piminov, D. N. Shatilov BINP SB RAS, Novosibirsk K. Ohmi KEK, Ibaraki E. Paoloni University of Pisa and INFN, Pisa M. Schioppa INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza) V. V. Smaluk BINP, Novosibirsk P. Valente INFN-Roma, Roma
	In the second half of 2007 a major upgrade has been implemented on the Frascati DAΦNE collider in order to test the novel idea of Crab Waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. At the same time the performances of relevant hardware components, such as fast injection kickers and shielded bellows have been improved relying on new design concepts. The collider has been successfully commissioned in this new configuration. The paper describes the new layout as well as several experimental results about linear and non-linear optics setup and optimization, damping of beam instabilities and discusses the obtained luminosity performances.
WEPP125	Analysis of the Vertical Beam Instability in CTF3 Combiner Ring and New RF Deflector Design	2791
	D. Alesini, C. Biscari, A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma)
	In the last CTF3 run (November 2007) a vertical beam instability has been found in the Combiner Ring during operation. Possible sources of the instability are the vertical deflecting modes excited by the beam in the RF deflectors. In the first part of the paper we illustrate the results of the beam dynamics analysis obtained by a dedicated tracking code that allows including the induced transverse wake field and the multi-bunch multi-passage effects. To reduce the effects of such vertical trapped modes, the RF deflectors have been modified and two new deflectors have been designed. They have been made in aluminium and have two more ports in the input and output coupler cells to absorb the beam induced field on the vertical modes. The design of the new deflectors and the RF measurements are then presented in the paper.
THPC156	Performances of the SPARC Laser and RF Synchronization Systems	3354
	A. Gallo, D. Alesini, M. Bellaveglia, G. Gatti, C. Vicario INFN/LNF, Frascati (Roma)
	The SPARC project consists in a 150 MeV S-band, high-brilliance linac followed by 6 undulators for FEL radiation production at 530 nm. The linac assembly has been completed and the SPARC scientific program is presently in progress. The low level RF control electronics to monitor and synchronize the RF phase of the accelerating structures along the linac and the laser shot on the photocathode has been commissioned and it is now fully operative. The laser synchronization is routinely monitored and slow drifts are automatically corrected by a dedicated shot-to-shot feedback system. A similar slow automatic regulation is implemented on each linac accelerating section acting either on low level or high power sliding lines. The phase noise in the 2 RF power stations is counteracted by fast intra-pulse phase feedback systems that have been developed and put in operation. Phase stability measurements taken over the whole synchronization system are reported, and performances of different synchronization architectures, micro-wave based or laser based, are compared.