IPAC2014 - List of Authors (Zimmermann, F.)

Paper	Title	Page
MOXAA01	Challenges for Highest Energy Circular Colliders	1
	F. Zimmermann, M. Benedikt, D. Schulte, J. Wenninger CERN, Geneva, Switzerland
	A new tunnel of 80-100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCC-ee/TLEP) as potential intermediate step, and a lepton-hadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, top-up injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.
	Slides MOXAA01 [27.493 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOXAA01
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TUPRO003	Fast Crab Cavity Failures in HL-LHC	997
SUSPSNE004	use link to see paper's listing under its alternate paper code
	B. Yee-Rendón, R. Lopez-Fernandez CINVESTAV, Mexico City, Mexico J. Barranco García EPFL, Lausanne, Switzerland R. Calaga, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland
	Crab cavities (CCs) are a key ingredient of the High-Luminosity Large Hadron Collider (HL-LHC) to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β* provided by the ATS optics. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, necessary to dump the beam. The simulations assume a realistic steady-state distribution to assess the beam losses for the HL-LHC. Additionally, some strategies are studied to mitigate the damage caused by the failures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO003
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TUPME027	Analysis of the Electron Cloud Observations with 25 ns Bunch Spacing at the LHC	1410
	G. Iadarola Naples University Federico II, Science and Technology Pole, Napoli, Italy G. Arduini, V. Baglin, D. Banfi, H. Bartosik, S.D. Claudet, C.O. Domínguez, J.F. Esteban Müller, G. Iadarola, T. Pieloni, G. Rumolo, E.N. Shaposhnikova, L.J. Tavian, C. Zannini, F. Zimmermann CERN, Geneva, Switzerland
	Electron Cloud (EC) effects have been identified as a major performance limitation for the Large Hadron Collider (LHC) when operating with the nominal bunch spacing of 25 ns. During the LHC Run 1 (2010 - 2013) the luminosity production mainly used beams with 50 ns spacing, while 25 ns beams were only employed for short periods in 2011 and 2012 for test purposes. On these occasions, observables such as pressure rise, heat load in the cold sections as well as clear signatures on bunch-by-bunch emittance blow up, particle loss and energy loss indicated the presence of an EC in a large portion of the LHC. The analysis of the recorded data, together with EC build up simulations, has led to a significant improvement of our understanding of the EC effect in the different components of the LHC. Studies were carried out both at injection energy (450 GeV) and at top energy (4 TeV) aiming at determining the energy dependence of the EC formation and its impact on the quality of the proton beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME027
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THPRI004	FCC-ee/CepC Beam-beam Simulations with Beamstrahlung	3766
	K. Ohmi KEK, Ibaraki, Japan F. Zimmermann CERN, Geneva, Switzerland
	Beamstrahlung, namely synchrotron radiation emitted during the beam-beam collision, can be an important effect for circular high-energy lepton colliders such as FCC-ee (TLEP). In this paper we study beam-beam effects in the presence of energy spreading and bunch lengthening due to beamstrahlung.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI004
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Paper

Title

Page

Challenges for Highest Energy Circular Colliders

1

F. Zimmermann, M. Benedikt, D. Schulte, J. Wenninger
CERN, Geneva, Switzerland

A new tunnel of 80-100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCC-ee/TLEP) as potential intermediate step, and a lepton-hadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, top-up injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

Slides MOXAA01 [27.493 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOXAA01

Export •

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

TUPRO003

Fast Crab Cavity Failures in HL-LHC

997

SUSPSNE004

use link to see paper's listing under its alternate paper code

B. Yee-Rendón, R. Lopez-Fernandez
CINVESTAV, Mexico City, Mexico
J. Barranco García
EPFL, Lausanne, Switzerland
R. Calaga, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland

Crab cavities (CCs) are a key ingredient of the High-Luminosity Large Hadron Collider (HL-LHC) to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β* provided by the ATS optics. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, necessary to dump the beam. The simulations assume a realistic steady-state distribution to assess the beam losses for the HL-LHC. Additionally, some strategies are studied to mitigate the damage caused by the failures.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO003

Export •

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

TUPME027

Analysis of the Electron Cloud Observations with 25 ns Bunch Spacing at the LHC

1410

G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy
G. Arduini, V. Baglin, D. Banfi, H. Bartosik, S.D. Claudet, C.O. Domínguez, J.F. Esteban Müller, G. Iadarola, T. Pieloni, G. Rumolo, E.N. Shaposhnikova, L.J. Tavian, C. Zannini, F. Zimmermann
CERN, Geneva, Switzerland

Electron Cloud (EC) effects have been identified as a major performance limitation for the Large Hadron Collider (LHC) when operating with the nominal bunch spacing of 25 ns. During the LHC Run 1 (2010 - 2013) the luminosity production mainly used beams with 50 ns spacing, while 25 ns beams were only employed for short periods in 2011 and 2012 for test purposes. On these occasions, observables such as pressure rise, heat load in the cold sections as well as clear signatures on bunch-by-bunch emittance blow up, particle loss and energy loss indicated the presence of an EC in a large portion of the LHC. The analysis of the recorded data, together with EC build up simulations, has led to a significant improvement of our understanding of the EC effect in the different components of the LHC. Studies were carried out both at injection energy (450 GeV) and at top energy (4 TeV) aiming at determining the energy dependence of the EC formation and its impact on the quality of the proton beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME027

Export •

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

THPRI004

FCC-ee/CepC Beam-beam Simulations with Beamstrahlung

3766

K. Ohmi
KEK, Ibaraki, Japan
F. Zimmermann
CERN, Geneva, Switzerland

Beamstrahlung, namely synchrotron radiation emitted during the beam-beam collision, can be an important effect for circular high-energy lepton colliders such as FCC-ee (TLEP). In this paper we study beam-beam effects in the presence of energy spreading and bunch lengthening due to beamstrahlung.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI004

Export •

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