IPAC2017 - List of Authors (Zisopoulos, P.)

Paper	Title	Page
MOPAB122	Fast Bunch by Bunch Tune Measurements at the CERN PS	415
	P. Zisopoulos, M. Gąsior, M. Serluca, G. Sterbini CERN, Geneva, Switzerland
	The CERN Proton Synchrotron (PS) is a crucial component of the Large Hadron Collider (LHC) injector complex. The PS role is to provide beams of high brightness and with the required time structure. In this paper, we present the results of bunch-by-bunch tune measurements by using turn-by-turn transverse beam position monitors (BPMs). The data from different BPMs are combined together to allow fast and accurate tune measurements for each bunch. The obtained results are compared with the present PS tune-meter system and the specific advantages and limits of this technique are commented and exemplified.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB122
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WEPIK068	Non-Linear Beam Dynamics Studies of the CLIC Damping Wiggler Prototype	3087
	J. Gethmann, A. Bernhard, E. Blomley, E. Huttel, A.-S. Müller, A.I. Papash, M. Schedler KIT, Karlsruhe, Germany Y. Papaphilippou, P. Zisopoulos CERN, Geneva, Switzerland K. Zolotarev BINP SB RAS, Novosibirsk, Russia
	Funding: Julian Gethmann acknowledges the support by the DFG-funded Doctoral School Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology First beam dynamics studies of a damping wiggler prototype for the CLIC damping rings have been carried out at the KIT storage ring. Effects of the 2.9 T superconducting wiggler on the electron beam in the 2.5 GeV standard operation mode have been measured and compared with theoretical predictions. Higher order multipole components were investigated using local orbit bump measurements. Based on these findings the simulation models for the storage ring optic have been adjusted. The refined optics model has been applied to the 1.3 GeV, low-operation case. This case will be used to experimentally benchmark beam dynamics simulations involving strong wiggler fields and dominant collective effects. We present these measurements, comparisons and the findings of the simulations with the updated low-mode optics model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK068
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WEPVA037	Machine Development Studies in the CERN PS Booster, in 2016	3339
	E. Benedetto, S.C.P. Albright, M.E. Angoletta, W. Bartmann, J.M. Belleman, A. Blas, M. Cieslak-Kowalska, G.P. Di Giovanni, A. Findlay, V. Forte, A. Garcia-Tabares, G. Guidoboni, S. Hancock, M. Jaussi, B. Mikulec, J.C. Molendijk, A. Oeftiger, T.L. Rijoff, F. Schmidt, P. Zisopoulos CERN, Geneva, Switzerland M. Cieslak-Kowalska EPFL, Lausanne, Switzerland P. Zisopoulos Uppsala University, Uppsala, Sweden
	The paper presents the outstanding studies performed in 2016 in preparation of the PS Booster upgrade, within the LHC Injector Upgrade project (LIU), to provide twice higher brightness and intensity to the High-Luminosity LHC. Major changes include the increase of injection and extraction energy, the implementation of a H⁻ charge-exchange injection system, the replacement of the present Main Power Supply and the deployment of a new RF system (and related Low-Level), based on the Finemet technology. Although the major improvements will be visible only after the upgrade, the present machine can already benefit of the work done, in terms of better brightness, transmission and improved reproducibility of the present operational beams. Studies address the space-charge limitations at low energy, for which a detailed optics model is needed and for which mitigation measurements are under study, and the blow-up reduction at injection in the downstream machine, for which the beams need careful preparation and transmission. Moreover they address the requirements and the reliability of new beam instrumentation and hardware that is being installed in view of LIU.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA037
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WEPVA038	Tail Repopulation Measurements in the PSB	3343
	E. Benedetto, M. Cieslak-Kowalska, P. Zisopoulos CERN, Geneva, Switzerland M. Cieslak-Kowalska EPFL, Lausanne, Switzerland
	The PS Booster (PSB) is the first circular accelerator in the LHC injector chain providing protons for the full CERN complex. Each of its four rings provides beams in a range of intensities varying from 40 e11 p/cycle to 0.8 e13 p/cycle. Low intensity beams are produced by transverse shaving, that is by scraping the tails, in order to tailor the intensity and transverse emittances. Eventually, tails repopulate and the beam profile reshapes, under the effect of space charge, which is dominant at low energy in the PS Booster. This paper describes the results of the measurements after the shaving process, where the tails are scraped but finally re-appear in the transverse profile, and it provides a first benchmark with space-charge simulations. It highlights the challenges encountered and the lessons learned, to guide the future experiments. The final outcome of these studies is the characterisation of the halo creation mechanism and the determination of the diffusion speed, important for the design of the future PS Booster scraping system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA038
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THPAB044	Development of Computational Tools for Noise Studies in the LHC	3807
SUSPSIK067	use link to see paper's listing under its alternate paper code
	S. Kostoglou, N. Karastathis, Y. Papaphilippou, D. Pellegrini, P. Zisopoulos CERN, Geneva, Switzerland P. Zisopoulos Uppsala University, Uppsala, Sweden
	Noise can have a significant impact on the beam dynamics in the LHC, enhancing diffusion processes and leading to emittance blowup. In order to study the details of such effects with computer simulations, a new set of tools is being developed. In particular, a demonstrator GPU-based particle tracker has been built profiting from the technology provided by the NVRTC Cuda library. Its performances for short term beam dynamic simulations in presence of many macro particles are highly promising. In addition, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm has been thoroughly inspected. Several alternatives to its fundamental steps have been investigated in a modern C++ implementation. The method was also used to produce Frequency Maps and benchmark these tools with other simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB044
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Paper

Title

Page

Fast Bunch by Bunch Tune Measurements at the CERN PS

415

P. Zisopoulos, M. Gąsior, M. Serluca, G. Sterbini
CERN, Geneva, Switzerland

The CERN Proton Synchrotron (PS) is a crucial component of the Large Hadron Collider (LHC) injector complex. The PS role is to provide beams of high brightness and with the required time structure. In this paper, we present the results of bunch-by-bunch tune measurements by using turn-by-turn transverse beam position monitors (BPMs). The data from different BPMs are combined together to allow fast and accurate tune measurements for each bunch. The obtained results are compared with the present PS tune-meter system and the specific advantages and limits of this technique are commented and exemplified.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB122

Export •

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

WEPIK068

Non-Linear Beam Dynamics Studies of the CLIC Damping Wiggler Prototype

3087

J. Gethmann, A. Bernhard, E. Blomley, E. Huttel, A.-S. Müller, A.I. Papash, M. Schedler
KIT, Karlsruhe, Germany
Y. Papaphilippou, P. Zisopoulos
CERN, Geneva, Switzerland
K. Zolotarev
BINP SB RAS, Novosibirsk, Russia

Funding: Julian Gethmann acknowledges the support by the DFG-funded Doctoral School Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology
First beam dynamics studies of a damping wiggler prototype for the CLIC damping rings have been carried out at the KIT storage ring. Effects of the 2.9 T superconducting wiggler on the electron beam in the 2.5 GeV standard operation mode have been measured and compared with theoretical predictions. Higher order multipole components were investigated using local orbit bump measurements. Based on these findings the simulation models for the storage ring optic have been adjusted. The refined optics model has been applied to the 1.3 GeV, low-operation case. This case will be used to experimentally benchmark beam dynamics simulations involving strong wiggler fields and dominant collective effects. We present these measurements, comparisons and the findings of the simulations with the updated low-mode optics model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK068

Export •

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

WEPVA037

Machine Development Studies in the CERN PS Booster, in 2016

3339

E. Benedetto, S.C.P. Albright, M.E. Angoletta, W. Bartmann, J.M. Belleman, A. Blas, M. Cieslak-Kowalska, G.P. Di Giovanni, A. Findlay, V. Forte, A. Garcia-Tabares, G. Guidoboni, S. Hancock, M. Jaussi, B. Mikulec, J.C. Molendijk, A. Oeftiger, T.L. Rijoff, F. Schmidt, P. Zisopoulos
CERN, Geneva, Switzerland
M. Cieslak-Kowalska
EPFL, Lausanne, Switzerland
P. Zisopoulos
Uppsala University, Uppsala, Sweden

The paper presents the outstanding studies performed in 2016 in preparation of the PS Booster upgrade, within the LHC Injector Upgrade project (LIU), to provide twice higher brightness and intensity to the High-Luminosity LHC. Major changes include the increase of injection and extraction energy, the implementation of a H⁻ charge-exchange injection system, the replacement of the present Main Power Supply and the deployment of a new RF system (and related Low-Level), based on the Finemet technology. Although the major improvements will be visible only after the upgrade, the present machine can already benefit of the work done, in terms of better brightness, transmission and improved reproducibility of the present operational beams. Studies address the space-charge limitations at low energy, for which a detailed optics model is needed and for which mitigation measurements are under study, and the blow-up reduction at injection in the downstream machine, for which the beams need careful preparation and transmission. Moreover they address the requirements and the reliability of new beam instrumentation and hardware that is being installed in view of LIU.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA037

Export •

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

WEPVA038

Tail Repopulation Measurements in the PSB

3343

E. Benedetto, M. Cieslak-Kowalska, P. Zisopoulos
CERN, Geneva, Switzerland
M. Cieslak-Kowalska
EPFL, Lausanne, Switzerland

The PS Booster (PSB) is the first circular accelerator in the LHC injector chain providing protons for the full CERN complex. Each of its four rings provides beams in a range of intensities varying from 40 e11 p/cycle to 0.8 e13 p/cycle. Low intensity beams are produced by transverse shaving, that is by scraping the tails, in order to tailor the intensity and transverse emittances. Eventually, tails repopulate and the beam profile reshapes, under the effect of space charge, which is dominant at low energy in the PS Booster. This paper describes the results of the measurements after the shaving process, where the tails are scraped but finally re-appear in the transverse profile, and it provides a first benchmark with space-charge simulations. It highlights the challenges encountered and the lessons learned, to guide the future experiments. The final outcome of these studies is the characterisation of the halo creation mechanism and the determination of the diffusion speed, important for the design of the future PS Booster scraping system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA038

Export •

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

THPAB044

Development of Computational Tools for Noise Studies in the LHC

3807

SUSPSIK067

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

S. Kostoglou, N. Karastathis, Y. Papaphilippou, D. Pellegrini, P. Zisopoulos
CERN, Geneva, Switzerland
P. Zisopoulos
Uppsala University, Uppsala, Sweden

Noise can have a significant impact on the beam dynamics in the LHC, enhancing diffusion processes and leading to emittance blowup. In order to study the details of such effects with computer simulations, a new set of tools is being developed. In particular, a demonstrator GPU-based particle tracker has been built profiting from the technology provided by the NVRTC Cuda library. Its performances for short term beam dynamic simulations in presence of many macro particles are highly promising. In addition, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm has been thoroughly inspected. Several alternatives to its fundamental steps have been investigated in a modern C++ implementation. The method was also used to produce Frequency Maps and benchmark these tools with other simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB044

Export •

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