IPAC2015 - List of Authors (Zannini, C.)

Paper	Title	Page
MOPJE035	An Extended SPS Longitudinal Impedance Model	360
	J.V. Campelo, T. Argyropoulos, T. Bohl, F. Caspers, J.F. Esteban Müller, J.B. Ghini, A. Lasheen, D. Quartullo, B. Salvant, E.N. Shaposhnikova, C. Zannini CERN, Geneva, Switzerland
	Longitudinal multi-bunch instability in the CERN SPS with a very low intensity threshold is a serious limitation for the future doubling of bunch intensity required by Hi-Lumi LHC project. A complete and accurate impedance model is essential to understand the nature of this instability and to plan possible cures. This contribution describes in detail the current longitudinal impedance model of the SPS. Recently, the model was updated with new findings and includes now the impedance of accelerating cavities, kicker and septum magnets, beam position monitors, vacuum Flanges, shielded and unshielded pumping ports, electrostatic septa and resistive wall. Electromagnetic simulations and bench measurements were used to build the model. The contribution from each element is described and compared to the total machine impedance. Together with relevant beam measurements and simulations, the analysis of the different sources of impedance is used to identify the source of the longitudinal instability limiting the SPS performance so that the responsible elements can be acted upon.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE035
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MOPJE049	Benchmarking the CERN-SPS Transverse Impedance Model with Measured Headtail Growth Rates	402
	C. Zannini, H. Bartosik, G. Iadarola, G. Rumolo, B. Salvant CERN, Geneva, Switzerland
	The latest SPS transverse impedance model includes kicker magnets, wall impedance, transition pieces (e.g. flanges and vacuum chamber discontinuities), beam position monitors and RF cavities. The model has already been successfully benchmarked against coherent tune shift and transverse mode coupling instability measurements. In this paper we present measurements of the headtail growth rates for a wide range of negative chromaticities and for two different configurations of machine optics (nominal and low gamma transition). The measurement results are compared with HEADTAIL simulations using the wake fields obtained from the SPS transverse impedance model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE049
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MOPJE050	Transverse Impedance Model of the CERN-PSB	406
	C. Zannini, G. Iadarola, K.S.B. Li, T.L. Rijoff, G. Rumolo CERN, Geneva, Switzerland B. Jones STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom T.L. Rijoff TU Darmstadt, Darmstadt, Germany
	In the framework of the PS-Booster upgrade project an accurate impedance model is needed in order to determine the effect on the beam stability and assess the impact of the new devices before installation in the machine. This paper describes the PSB impedance model which includes resistive wall, indirect space charge, flanges, step transitions, ejection kicker including cables, injection kickers and cavities. Each impedance contribution has been computed for different energies in the PSB cycle. Measurements of the coherent tune shifts have been performed and compared to calculations based on the impedance model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE050
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WEPHA002	Electromagnetic Characterization of NEG Properties Above 200 GHz for the CLIC Damping Rings	3097
	E. Koukovini-Platia, G. Iadarola, G. Rumolo, C. Zannini CERN, Geneva, Switzerland
	Non-Evaporable Getter (NEG) will be used in the CLIC electron damping rings (EDR) to suppress fast beam ion instabilities due to its effective pumping ability. The electromagnetic (EM) characterization of the NEG properties up to high frequencies is required for the correct impedance modeling of the DR components. The properties are determined using WR-3.4 and WR-1.5 rectangular waveguides, based on a combination of experimental measurements of the complex transmission coefficient S21 with a Vector Network Analyzer (VNA) and CST 3D EM simulations, for the frequency range of 220-330 GHz and 500-750 GHz. The results obtained using NEG-coated Aluminum (Al) waveguides are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA002
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THPF086	A New Hardware Design for PSB Kicker Magnets (KSW) for the 35 mm Transverse Painting in the Horizontal Plane	3890
	L.M.C. Feliciano, C. Bracco, L. Ducimetière, T. Fowler, G. Gräwer, R. Noulibos, L. Sermeus, W.J.M. Weterings, C. Zannini CERN, Geneva, Switzerland
	The changeover from Linac2 to Linac4 in CERN’s injector chain will allow increasing the injection energy into the PS Booster from 50 MeV to 160 MeV. Transverse phase space painting will be performed in the horizontal plane, by means of four stacks of four KSW kicker magnets. The KSW magnets are located outside the injection region and will produce a 35 mm closed orbit bump, with falling amplitude during the injection to accomplish transverse phase space painting to the required emittance. New magnets with two different types of coils are being built using the existing design. The magnets are made of two halves, which are assembled together around a vacuum ceramic chamber. In order to reduce the beam impedance, the ceramic chamber is internally coated by a thin titanium layer. A new multiple-linear waveform generator has been developed to provide the high flexibility in the KSW kicker magnets current decay to fulfil the requirements of all the different users (LHC, nTOF, ISOLDE, CNGS, etc.).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF086
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Paper

Title

Page

An Extended SPS Longitudinal Impedance Model

360

J.V. Campelo, T. Argyropoulos, T. Bohl, F. Caspers, J.F. Esteban Müller, J.B. Ghini, A. Lasheen, D. Quartullo, B. Salvant, E.N. Shaposhnikova, C. Zannini
CERN, Geneva, Switzerland

Longitudinal multi-bunch instability in the CERN SPS with a very low intensity threshold is a serious limitation for the future doubling of bunch intensity required by Hi-Lumi LHC project. A complete and accurate impedance model is essential to understand the nature of this instability and to plan possible cures. This contribution describes in detail the current longitudinal impedance model of the SPS. Recently, the model was updated with new findings and includes now the impedance of accelerating cavities, kicker and septum magnets, beam position monitors, vacuum Flanges, shielded and unshielded pumping ports, electrostatic septa and resistive wall. Electromagnetic simulations and bench measurements were used to build the model. The contribution from each element is described and compared to the total machine impedance. Together with relevant beam measurements and simulations, the analysis of the different sources of impedance is used to identify the source of the longitudinal instability limiting the SPS performance so that the responsible elements can be acted upon.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE035

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPJE049

Benchmarking the CERN-SPS Transverse Impedance Model with Measured Headtail Growth Rates

402

C. Zannini, H. Bartosik, G. Iadarola, G. Rumolo, B. Salvant
CERN, Geneva, Switzerland

The latest SPS transverse impedance model includes kicker magnets, wall impedance, transition pieces (e.g. flanges and vacuum chamber discontinuities), beam position monitors and RF cavities. The model has already been successfully benchmarked against coherent tune shift and transverse mode coupling instability measurements. In this paper we present measurements of the headtail growth rates for a wide range of negative chromaticities and for two different configurations of machine optics (nominal and low gamma transition). The measurement results are compared with HEADTAIL simulations using the wake fields obtained from the SPS transverse impedance model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE049

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPJE050

Transverse Impedance Model of the CERN-PSB

406

C. Zannini, G. Iadarola, K.S.B. Li, T.L. Rijoff, G. Rumolo
CERN, Geneva, Switzerland
B. Jones
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
T.L. Rijoff
TU Darmstadt, Darmstadt, Germany

In the framework of the PS-Booster upgrade project an accurate impedance model is needed in order to determine the effect on the beam stability and assess the impact of the new devices before installation in the machine. This paper describes the PSB impedance model which includes resistive wall, indirect space charge, flanges, step transitions, ejection kicker including cables, injection kickers and cavities. Each impedance contribution has been computed for different energies in the PSB cycle. Measurements of the coherent tune shifts have been performed and compared to calculations based on the impedance model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE050

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA002

Electromagnetic Characterization of NEG Properties Above 200 GHz for the CLIC Damping Rings

3097

E. Koukovini-Platia, G. Iadarola, G. Rumolo, C. Zannini
CERN, Geneva, Switzerland

Non-Evaporable Getter (NEG) will be used in the CLIC electron damping rings (EDR) to suppress fast beam ion instabilities due to its effective pumping ability. The electromagnetic (EM) characterization of the NEG properties up to high frequencies is required for the correct impedance modeling of the DR components. The properties are determined using WR-3.4 and WR-1.5 rectangular waveguides, based on a combination of experimental measurements of the complex transmission coefficient S21 with a Vector Network Analyzer (VNA) and CST 3D EM simulations, for the frequency range of 220-330 GHz and 500-750 GHz. The results obtained using NEG-coated Aluminum (Al) waveguides are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA002

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF086

A New Hardware Design for PSB Kicker Magnets (KSW) for the 35 mm Transverse Painting in the Horizontal Plane

3890

L.M.C. Feliciano, C. Bracco, L. Ducimetière, T. Fowler, G. Gräwer, R. Noulibos, L. Sermeus, W.J.M. Weterings, C. Zannini
CERN, Geneva, Switzerland

The changeover from Linac2 to Linac4 in CERN’s injector chain will allow increasing the injection energy into the PS Booster from 50 MeV to 160 MeV. Transverse phase space painting will be performed in the horizontal plane, by means of four stacks of four KSW kicker magnets. The KSW magnets are located outside the injection region and will produce a 35 mm closed orbit bump, with falling amplitude during the injection to accomplish transverse phase space painting to the required emittance. New magnets with two different types of coils are being built using the existing design. The magnets are made of two halves, which are assembled together around a vacuum ceramic chamber. In order to reduce the beam impedance, the ceramic chamber is internally coated by a thin titanium layer. A new multiple-linear waveform generator has been developed to provide the high flexibility in the KSW kicker magnets current decay to fulfil the requirements of all the different users (LHC, nTOF, ISOLDE, CNGS, etc.).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF086

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)