IPAC2012 - List of Authors (Demma, T.)

Paper

Title

Page

Experimental Measurements of e-Cloud Mitigation using Clearing Electrodes in the DAΦNE Collider

1107

D. Alesini, T. Demma, A. Drago, A. Gallo, S. Guiducci, C. Milardi, P. Raimondi, M. Zobov
INFN/LNF, Frascati (Roma), Italy
S. De Santis
LBNL, Berkeley, California, USA

Recently the electron-positron collider DAΦNE has started delivering luminosity to the KLOE-2 experiment. For this run special metallic electrodes for e-cloud clearing were installed in all the dipole and wiggler magnets of the collider positron ring. Experimental measurements of the effectiveness of the electrodes in the mitigation of the e-cloud effects in the positron beam have been done showing an impressive effectiveness of these devices in the cure of the e-cloud effects in the positron beam. In particular the electrodes allow reducing the vertical beam size increase, the growth rate of transverse instabilities and the tune shifts induced by the electron cloud. Frequency shifts measurements of the vacuum chamber resonances switching on and off the electrodes have also been done showing their effect in the reduction of the electron cloud density. In this paper we summarize the results of all our observations and the experimental measurements of the e-cloud suppression with these electrodes.

Slides TUOBC03 [2.825 MB]

TUPPR057

Intrabeam Scattering Studies at the Swiss Light Source

1951

F. Antoniou, Y. Papaphilippou
CERN, Geneva, Switzerland
M. Aiba, M. Böge, N. Milas, A. Streun
Paul Scherrer Institut, Villigen, Switzerland
T. Demma
INFN/LNF, Frascati (Roma), Italy

The target parameters of modern ultra-low emittance rings are entering into a regime where intra-beam scattering (IBS) becomes important and, in the case of linear collider damping rings, even a limitation for the delivered emittances. The Swiss Light Source (SLS) storage ring, as it has achieved a vertical geometrical emittance of around 2 pm at 2.4 GeV, and it has the ability to run at even lower energies, and the availability of emittance monitoring diagnostics, is an ideal test bed for IBS studies. Simulations using the classical IBS theories and tracking codes are undertaken in order to explore the possibilities and limitations for IBS measurements at the SLS. In this respect, comparison between the theories and codes is first discussed. The dependence of the output emittances, taking into account the effect of IBS, with respect to energy, bunch charge and zero current vertical and longitudinal emittance is also studied, in order to define the regimes where the IBS effect can be significant. First measurement results from the SLS running at lower energies are finally presented.

WEPPR091

Multi-Particle Simulation Codes Implementation to Include Models of a Novel Single-bunch Feedback System and Intra-beam Scattering

3147

M.T.F. Pivi, A. Chao, C.H. Rivetta
SLAC, Menlo Park, California, USA
F. Antoniou, K.S.B. Li, Y. Papaphilippou
CERN, Geneva, Switzerland
M. Boscolo, T. Demma
INFN/LNF, Frascati (Roma), Italy
K.G. Sonnad
CLASSE, Ithaca, New York, USA

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP).
The beam tracking codes C-MAD and HEAD-TAIL have been enhanced to include a detailed model of a single-bunch feedback system. Such a system is under development to mitigate the electron cloud and the transverse mode coupling instability (TMCI) in the SPS and LHC at CERN. This paper presents the model of the feedback sub-systems: receiver, processing channel, filter, amplifier and kicker, which takes into account the frequency response, noise, mismatching and technological limits. With a realistic model of the hardware, it is possible to study the prototypes installed in the SPS and design a novel feedback system. The C-MAD code, which is parallel and optimized for speed, now also includes radiation damping and quantum excitation and a detailed model of Intra-Beam Scattering (IBS) based on the Zenkevich-Bolshakov algorithm, to investigate the IBS during damping and its effect on the beam distribution, especially the beam tails, that analytical methods cannot investigate. Intra-beam scattering is a limiting factor for ultra-low emittance rings such as CLIC and Super-B.

TUPPC073

Frequency Map Analysis for SuperB

1341

S.M. Liuzzo, M.E. Biagini, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
T. Demma
LAL, Orsay, France
Y. Papaphilippou
CERN, Geneva, Switzerland

The frequency map analysis is applied to the SuperB HER and LER lattices including the Final Focus, in order to understand the dynamic aperture limitation and provide insight for a working point optimization. In this respect, frequency and diffusion maps are evaluated applying random magnet misalignments and tilts, before and after correction of orbit, dispersion and coupling using Low Emittance Tuning techniques. The same analysis is performed for on and off momentum particles. The lattice properties are further investigated using working point scans and the correction of non linear resonance driving terms and amplitude detuning.

TUPPR088

Baseline Design of the SuperB Factory Injection System

2032

S. Guiducci, A. Bacci, M.E. Biagini, R. Boni, M. Boscolo, D. Pellegrini, M.A. Preger, P. Raimondi, A.R. Rossi, M. Zobov
INFN/LNF, Frascati (Roma), Italy
M.A. Baylac
LPSC, Grenoble, France
J. Brossard, S. Cavalier, O. Dadoun, T. Demma, P. Lepercq, E. Ngo Mandag, C. Rimbault, A. Variola
LAL, Orsay, France
J.T. Seeman
SLAC, Menlo Park, California, USA
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia

The injection complex of the SuperB, B-factory project of INFN consists of a polarized electron gun, a positron production system, electron and positron linac sections, a positron damping ring and the transfer lines connecting these systems and the collider main rings. To keep the ultra high luminosity nearly constant, continuous injection of 4 GeV electrons and 7 GeV positrons in both Low Energy Ring (LER) and High Energy Ring (HER) is necessary. In this paper we describe the baseline design and the beam dynamics studies performed to evaluate the system performance.

Paper	Title	Page
TUOBC03	Experimental Measurements of e-Cloud Mitigation using Clearing Electrodes in the DAΦNE Collider	1107
	D. Alesini, T. Demma, A. Drago, A. Gallo, S. Guiducci, C. Milardi, P. Raimondi, M. Zobov INFN/LNF, Frascati (Roma), Italy S. De Santis LBNL, Berkeley, California, USA
	Recently the electron-positron collider DAΦNE has started delivering luminosity to the KLOE-2 experiment. For this run special metallic electrodes for e-cloud clearing were installed in all the dipole and wiggler magnets of the collider positron ring. Experimental measurements of the effectiveness of the electrodes in the mitigation of the e-cloud effects in the positron beam have been done showing an impressive effectiveness of these devices in the cure of the e-cloud effects in the positron beam. In particular the electrodes allow reducing the vertical beam size increase, the growth rate of transverse instabilities and the tune shifts induced by the electron cloud. Frequency shifts measurements of the vacuum chamber resonances switching on and off the electrodes have also been done showing their effect in the reduction of the electron cloud density. In this paper we summarize the results of all our observations and the experimental measurements of the e-cloud suppression with these electrodes.
	Slides TUOBC03 [2.825 MB]

TUPPR057	Intrabeam Scattering Studies at the Swiss Light Source	1951
	F. Antoniou, Y. Papaphilippou CERN, Geneva, Switzerland M. Aiba, M. Böge, N. Milas, A. Streun Paul Scherrer Institut, Villigen, Switzerland T. Demma INFN/LNF, Frascati (Roma), Italy
	The target parameters of modern ultra-low emittance rings are entering into a regime where intra-beam scattering (IBS) becomes important and, in the case of linear collider damping rings, even a limitation for the delivered emittances. The Swiss Light Source (SLS) storage ring, as it has achieved a vertical geometrical emittance of around 2 pm at 2.4 GeV, and it has the ability to run at even lower energies, and the availability of emittance monitoring diagnostics, is an ideal test bed for IBS studies. Simulations using the classical IBS theories and tracking codes are undertaken in order to explore the possibilities and limitations for IBS measurements at the SLS. In this respect, comparison between the theories and codes is first discussed. The dependence of the output emittances, taking into account the effect of IBS, with respect to energy, bunch charge and zero current vertical and longitudinal emittance is also studied, in order to define the regimes where the IBS effect can be significant. First measurement results from the SLS running at lower energies are finally presented.

WEPPR091	Multi-Particle Simulation Codes Implementation to Include Models of a Novel Single-bunch Feedback System and Intra-beam Scattering	3147
	M.T.F. Pivi, A. Chao, C.H. Rivetta SLAC, Menlo Park, California, USA F. Antoniou, K.S.B. Li, Y. Papaphilippou CERN, Geneva, Switzerland M. Boscolo, T. Demma INFN/LNF, Frascati (Roma), Italy K.G. Sonnad CLASSE, Ithaca, New York, USA
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP). The beam tracking codes C-MAD and HEAD-TAIL have been enhanced to include a detailed model of a single-bunch feedback system. Such a system is under development to mitigate the electron cloud and the transverse mode coupling instability (TMCI) in the SPS and LHC at CERN. This paper presents the model of the feedback sub-systems: receiver, processing channel, filter, amplifier and kicker, which takes into account the frequency response, noise, mismatching and technological limits. With a realistic model of the hardware, it is possible to study the prototypes installed in the SPS and design a novel feedback system. The C-MAD code, which is parallel and optimized for speed, now also includes radiation damping and quantum excitation and a detailed model of Intra-Beam Scattering (IBS) based on the Zenkevich-Bolshakov algorithm, to investigate the IBS during damping and its effect on the beam distribution, especially the beam tails, that analytical methods cannot investigate. Intra-beam scattering is a limiting factor for ultra-low emittance rings such as CLIC and Super-B.

TUPPC073	Frequency Map Analysis for SuperB	1341
	S.M. Liuzzo, M.E. Biagini, P. Raimondi INFN/LNF, Frascati (Roma), Italy T. Demma LAL, Orsay, France Y. Papaphilippou CERN, Geneva, Switzerland
	The frequency map analysis is applied to the SuperB HER and LER lattices including the Final Focus, in order to understand the dynamic aperture limitation and provide insight for a working point optimization. In this respect, frequency and diffusion maps are evaluated applying random magnet misalignments and tilts, before and after correction of orbit, dispersion and coupling using Low Emittance Tuning techniques. The same analysis is performed for on and off momentum particles. The lattice properties are further investigated using working point scans and the correction of non linear resonance driving terms and amplitude detuning.

TUPPR088	Baseline Design of the SuperB Factory Injection System	2032
	S. Guiducci, A. Bacci, M.E. Biagini, R. Boni, M. Boscolo, D. Pellegrini, M.A. Preger, P. Raimondi, A.R. Rossi, M. Zobov INFN/LNF, Frascati (Roma), Italy M.A. Baylac LPSC, Grenoble, France J. Brossard, S. Cavalier, O. Dadoun, T. Demma, P. Lepercq, E. Ngo Mandag, C. Rimbault, A. Variola LAL, Orsay, France J.T. Seeman SLAC, Menlo Park, California, USA D.N. Shatilov BINP SB RAS, Novosibirsk, Russia
	The injection complex of the SuperB, B-factory project of INFN consists of a polarized electron gun, a positron production system, electron and positron linac sections, a positron damping ring and the transfer lines connecting these systems and the collider main rings. To keep the ultra high luminosity nearly constant, continuous injection of 4 GeV electrons and 7 GeV positrons in both Low Energy Ring (LER) and High Energy Ring (HER) is necessary. In this paper we describe the baseline design and the beam dynamics studies performed to evaluate the system performance.