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MPPP024 |
Recent Observations on a Horizontal Instability in the DAFNE Positron Ring
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1841 |
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- A. Drago, M. Zobov
INFN/LNF, Frascati (Roma)
- D. Teytelman
SLAC, Menlo Park, California
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A strong horizontal instability limits the maximum positron current storable in the DAFNE Phi-Factory. A powerful feedback system makes it possible to store and collide up to 1250 mA of positron current in 105 bunches. Nevertheless, a much higher current (> 2.4A) has been successfully stored in the twin electron ring. Measurements have been carried out to understand the positron current limit and to characterize the behavior of the horizontal instability at high current with different bunch patterns. Grow/damp turn-by-turn data obtained by turning off the horizontal feedback have been acquired and analyzed. Spectral analysis and grow rates of the instability are shown. In particular, the -1 mode has strong evidence and fast grow rate. Its grow rate behavior is analyzed at different beam currents and bunch patterns.
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TPAE002 |
The Project PLASMONX for Plasma Acceleration Experiments and a Thomson X-Ray Source at SPARC
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820 |
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- L. Serafini, F. Alessandria, A. Bacci, I. Boscolo, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, M. Mauri, V. Petrillo, R. Pozzoli, M. Rome
INFN-Milano, Milano
- D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, 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, S. Guiducci, 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)
- W. Baldeschi, A. Barbini, M. Galimberti, A. Giulietti, A. Gizzi, P. Koester, L. Labate, A. Rossi, P. Tommasini
CNR/IPP, Pisa
- R. Bonifacio, N. Piovella
Universita' degli Studi di Milano, MILANO
- U. Bottigli, B. Golosio, P.N. Oliva, A. Poggiu, S. Stumbo
INFN-Cagliari, Monserrato (Cagliari)
- F. Broggi
INFN/LASA, Segrate (MI)
- C.A. Cecchetti, D. Giulietti
UNIPI, Pisa
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We present the status of the activity on the project PLASMONX, which foresees the installation of a multi-TW Ti:Sa laser system at the CNR-ILIL laboratory to conduct plasma acceleration experiments and the construction of an additional beam line at SPARC to develop a Thomson X-ray source at INFN-LNF. After pursuing self-injection experiments at ILIL, when the electron beam at SPARC will be available the SPARC laser system will be upgraded to TW power level in order to conduct either external injection plasma acceleration experiments and ultra-bright X-ray pulse generation with the Thomson source. Results of numerical simulations modeling the interaction of the SPARC electron beam and the counter-propagating laser beam are presented with detailed discussion of the monochromatic X-ray beam spectra generated by Compton backscattering: X-ray energies are tunable in the range 20 to 1000 keV, with pulse duration from 30 fs to 20 ps. Preliminary simulations of plasma acceleration with self-injection are illustrated, as well as external injection of the SPARC electron beam. The proposed time schedule for this initiative is finally shown, which is tightly correlated with the progress of the SPARC project.
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ROAA001 |
DAFNE Operation and Plans for DAFNE2
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112 |
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- M. Zobov, D. Alesini, G. Benedetti, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, A. Clozza, G.O. Delle Monache, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, C. Vaccarezza, M. Vescovi
INFN/LNF, Frascati (Roma)
- J.D. Fox, D. Teytelman
SLAC, Menlo Park, California
- E. Levichev, P.A. Piminov, D.N. Shatilov
BINP SB RAS, Novosibirsk
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The e+e- collider DAFNE, a 1.02 Gev c.m. Phi-factory, has exceeded 1.2 1032 cm-2s-1 peak luminosity with 7.5 pb-1 maximum daily integrated luminosity. At the present performance the physics program of the three main experiments DEAR, FINUDA and KLOE will be completed by mid 2007. In this paper we describe the steps which have led to the luminosity improvement and present proposals for the upgrade of the collider towards higher energy and/or luminosity. The main accelerator issues on which we are planning to rely for this purpose, such as lattices with negative momentum compaction, strong RF focusing, design of high field magnets and Linac upgrade, are discussed in detail.
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ROAA003 |
Proposal of an Experiment on Bunch Length Modulation in DAFNE
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336 |
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- C. Biscari, D. Alesini, G. Benedetti, M.E. Biagini, R. Boni, M. Boscolo, A. Clozza, G.O. Delle Monache, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, C. Vaccarezza, M. Vescovi, M. Zobov
INFN/LNF, Frascati (Roma)
- J.M. Byrd, F. Sannibale
LBNL, Berkeley, California
- J.D. Fox, D. Teytelman
SLAC, Menlo Park, California
- E. Levichev, P.A. Piminov, D.N. Shatilov
BINP SB RAS, Novosibirsk
- C. Pagani
INFN/LASA, Segrate (MI)
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Obtaining very short bunches is a challenge for colliders and Coherent Synchrotron Radiation sources as well. The modulation of the bunch length in a strong RF focusing regime has been proposed, corresponding to a large value of the synchrotron tune. A ring structure where the dependence of the longitudinal position of a particle on its energy (R56) along the ring oscillates between large positive and negative values can produce a bunch length modulation. The synchrotron frequency can be tuned both by means of the rf voltage and by the integral of R56, down to the limit of zero value corresponding to the isochronicity condition. We present here the proposal of bunch length modulation along the DAFNE rings. Its lattice can be tuned to positive or negative momentum compaction, or to structures in which the two arcs are alternately set to positive/negative integrals of R56. With the proposed installation of an extra RF system at 1.3 GHz, experiments on bunch length modulation both in the high and low synchrotron tune regimes can be realized.
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RPAT098 |
Phase-Space Dynamic Tracking by a Two Pickups Data Acquisition System
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4326 |
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- A. Drago, M.E. Biagini, S. Guiducci, C. Milardi, M.A. Preger, C. Vaccarezza, M. Zobov
INFN/LNF, Frascati (Roma)
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A two pickups dynamic tracking data acquisition system has been developed at LNF for the DAFNE Phi-factory. Two oscilloscopes sample horizontal and vertical sum and difference signals from two pickups simultaneously; the sampling clock is locked to the DAFNE timing system. A horizontal kick excites the beam motion and initiates the acquisition. Turn-by-turn signals are converted to beam position and stored on a server in a database using timestamp labels. Oscillation amplitude versus time, phase space distribution and frequency domain analysis are shown for several lattices and different settings of sextupoles and octupoles. Results are used to check the DAFNE non-linear model.
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RPPP001 |
Commissioning and First Measurements on the CTF3 Chicane
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785 |
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- A. Ghigo, D. Alesini, G. Benedetti, C. Biscari, M. Castellano, A. Drago, D. Filippetto, F. Marcellini, C. Milardi, B. Preger, M. Serio, F. Sgamma, A. Stella, M. Zobov
INFN/LNF, Frascati (Roma)
- R. Corsini, T. Lefevre, F. Tecker
CERN, Geneva
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The transfer line between the linac and the first recombination ring (Delay Loop) of the CTF3 project hs been installed at CERN in spring-summer 2004. In the transfer line a magnetic chicane is used to tune the length of the bunches coming from the linac in order to minimize the Coherent Synchrotron Radiation contribution to the beam energy spread in the recombination system. The first measurements of the beam parameters at several linac and stretcher settings are described. We report the compression curve as a function of the optical parameter R56 representing the dependence of the longitudinal position of a particle on its energy, obtained by measuring the bunch length with a 3 GHz RF deflector.
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FPAP001 |
Electron Cloud Build-Up Study for DAFNE
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779 |
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- C. Vaccarezza, R. Cimino, A. Drago, M. Zobov
INFN/LNF, Frascati (Roma)
- G. Bellodi
CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
- K. Ohmi
KEK, Ibaraki
- M.T.F. Pivi
SLAC, Menlo Park, California
- G. Rumolo
GSI, Darmstadt
- D. Schulte, F. Zimmermann
CERN, Geneva
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After the first experimental observations compatible with the presence of the electron cloud effect in the DAFNE positron ring, a more systematic study has been performed regarding the e-cloud build-up and related instability. The measured field map of the magnetic field has been taken into account in the simulation for elements present in the four 10 m long bending sections, representing 40% of the whole positron ring. The simulation results obtained with different codes are presented and compared with the recent experimental observations performed on the beam instabilities and the vacuum behavior of the positron ring.
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RPPT013 |
Status of the SPARC Project
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1327 |
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- L. Serafini, F. Alessandria, A. Bacci, S. Cialdi, C. De Martinis, D. Giove, M. Mauri, M. Rome, L. Serafini
INFN-Milano, Milano
- D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, 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, S. Guiducci, 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)
- I. Boscolo, C. Maroli, V. Petrillo
Universita' degli Studi di Milano, MILANO
- F. Broggi
INFN/LASA, Segrate (MI)
- L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, S. Tazzari
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)
- D. Dowell, P. Emma, C. Limborg-Deprey, D.T. Palmer
SLAC, Menlo Park, California
- D. Levi, M. Mattioli, G. Medici, P. Musumeci, D. Pelliccia
Università di Roma I La Sapienza, Roma
- M. Nisoli, S. Stagira, S. de Silvestri
Politecnico/Milano, Milano
- M. Petrarca
INFN-Roma, Roma
- J.B. Rosenzweig
UCLA, Los Angeles, California
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The SPARC project has entered its installation phase at INFN-LNF: its main goal is the promotion of an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments. The design of the 150 MeV photoinjector has been completed and the construction of its main components is in progress, as well as the design of the 12 m undulator. In this paper we will report on the installation and test of some major components, like the Ti:Sa laser system to drive the photo-cathode, the RF gun, the RF power system, as well as some test results on the RF deflector and 4th harmonic X-band cavity prototypes. Advancements in the control and beam diagnostics systems will also be reported, in particular on the emittance-meter device for beam emittance measurements in the drift space downstream the RF gun. Recent results on laser pulse shaping, obtained with two alternative techniques (DAZZLER and Liquid Crystal Mask), show the feasibility of producing 10 ps flat-top laser pulses in the UV with rise time below 1 ps, as needed to maximize the achievable beam brightness. First FEL experiments have been proposed, using SASE, seeding and non-linear resonant harmonics: these will be briefly described.
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