IPAC2015 - List of Authors (Huschauer, A.)

Paper	Title	Page
MOPJE045	Fixed Points in Presence of Space Charge in Circular Particle Accelerators	389
	M. Giovannozzi, S.S. Gilardoni, A. Huschauer CERN, Geneva, Switzerland S. Machida, C.R. Prior, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Recent measurements performed in the framework of the multi-turn extraction (MTE) studies showed a dependence of the position of beamlets obtained by crossing a stable transverse resonance on the total beam intensity. This novel observation has triggered a number of studies aiming at understanding the source of the observed effect. In this paper the results of numerical simulations performed in different conditions are discussed in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE045
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MOPJE046	Influence of the Alignment of the Main Magnets on Resonances in the CERN Proton Synchrotron	392
	A. Huschauer, S.S. Gilardoni, R. Wasef CERN, Geneva, Switzerland
	During the Long Shutdown 1 seven out of the one hundred combined function PS main magnets were removed from the tunnel to conduct maintenance. After reinstallation, the main magnets were aligned to the reference positions and within the first week of operation of the accelerator, a beam-based re-alignment campaign was performed to reduce the excursions of the closed orbit. In order to further investigate and understand the source of betatronic resonances, which, already in 2011, were found to be excited by the bare machine, tune diagram measurements before and after this beam-based magnet alignment were conducted. In both cases the same resonances as in 2011 were found to be present; however, after the alignment, an overall increase of their strengths was observed. In this paper we present the corresponding measurement results and discuss the direct impact on the daily operation of the accelerator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE046
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MOPJE047	Chromaticity Dependence of the Transverse Effective Impedance in the CERN Proton Synchrotron	395
	S. Persichelli, N. Biancacci, S.S. Gilardoni, A. Huschauer, E. Métral, B. Salvant, R. Wasef CERN, Geneva, Switzerland M. Migliorati University of Rome La Sapienza, Rome, Italy
	The current knowledge of the transverse impedance of the Proton Synchrotron (PS) has been established with beam-based measurements at different energies. The transverse coherent tune shift as a function of the beam intensity has been measured in order to evaluate the total effective imaginary part of the transverse impedance and its localization in the accelerator at the energies of 2, 7, 13 and 25 GeV. Measurements have been performed changing the chromaticity for every tune shift scan with intensity. The data analysis revealed an increase of impedance with chromaticity for all the energies considered. That transverse impedance can be compared with the previously evaluated theoretical impedance budget taking into account the individual contribution of several machine devices. The missing impedance is finally highlighted.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Fixed Points in Presence of Space Charge in Circular Particle Accelerators

389

M. Giovannozzi, S.S. Gilardoni, A. Huschauer
CERN, Geneva, Switzerland
S. Machida, C.R. Prior, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Recent measurements performed in the framework of the multi-turn extraction (MTE) studies showed a dependence of the position of beamlets obtained by crossing a stable transverse resonance on the total beam intensity. This novel observation has triggered a number of studies aiming at understanding the source of the observed effect. In this paper the results of numerical simulations performed in different conditions are discussed in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE045

Export •

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

MOPJE046

Influence of the Alignment of the Main Magnets on Resonances in the CERN Proton Synchrotron

392

A. Huschauer, S.S. Gilardoni, R. Wasef
CERN, Geneva, Switzerland

During the Long Shutdown 1 seven out of the one hundred combined function PS main magnets were removed from the tunnel to conduct maintenance. After reinstallation, the main magnets were aligned to the reference positions and within the first week of operation of the accelerator, a beam-based re-alignment campaign was performed to reduce the excursions of the closed orbit. In order to further investigate and understand the source of betatronic resonances, which, already in 2011, were found to be excited by the bare machine, tune diagram measurements before and after this beam-based magnet alignment were conducted. In both cases the same resonances as in 2011 were found to be present; however, after the alignment, an overall increase of their strengths was observed. In this paper we present the corresponding measurement results and discuss the direct impact on the daily operation of the accelerator.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE046

Export •

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

MOPJE047

Chromaticity Dependence of the Transverse Effective Impedance in the CERN Proton Synchrotron

395

S. Persichelli, N. Biancacci, S.S. Gilardoni, A. Huschauer, E. Métral, B. Salvant, R. Wasef
CERN, Geneva, Switzerland
M. Migliorati
University of Rome La Sapienza, Rome, Italy

The current knowledge of the transverse impedance of the Proton Synchrotron (PS) has been established with beam-based measurements at different energies. The transverse coherent tune shift as a function of the beam intensity has been measured in order to evaluate the total effective imaginary part of the transverse impedance and its localization in the accelerator at the energies of 2, 7, 13 and 25 GeV. Measurements have been performed changing the chromaticity for every tune shift scan with intensity. The data analysis revealed an increase of impedance with chromaticity for all the energies considered. That transverse impedance can be compared with the previously evaluated theoretical impedance budget taking into account the individual contribution of several machine devices. The missing impedance is finally highlighted.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE047

Export •

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