HB2018 - List of Authors (Karpov, I.)

Paper	Title	Page
TUP1WA03	Beam Instabilities After Injection to the LHC	163
	H. Timko, T. Argyropoulos, I. Karpov, E.N. Shaposhnikova CERN, Geneva, Switzerland
	Long-lasting phase oscillations have been observed at injection into the LHC since its first start-up with beam. These oscillations, however, were not leading to noticeable losses or blow-up in operation, and were therefore not studied in detail. In 2017, dedicated measurements with high-intensity bunches revealed that oscillations can lead to losses even slightly below the baseline intensity for the high-luminosity upgrade of the LHC. For the first time, high-resolution bunch profile acquisitions were triggered directly at injection and the formation of large-amplitude non-rigid dipole oscillations was observed on a turn-by-turn basis. First simulations can reproduce this instability via bunch filamentation that takes place after injection, depending on the mismatch between the bunch and bucket size in momentum at injection.
	Slides TUP1WA03 [2.166 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP1WA03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP2PO003	Beam Loading and Longitudinal Stability Evaluation for the FCC-ee Rings	266
	I. Karpov, P. Baudrenghien CERN, Geneva, Switzerland
	In high-current accelerators, interaction of the beam with fundamental impedance of the accelerating cavities can limit machine performance. It can result in a significant variation of bunch-by-bunch parameters (bunch length, synchronous phase, etc.) and lead to longitudinal coupled-bunch instability. In this work, these limitations are analysed together with possible cures for the high-current option (Z machine) of the future circular electron-positron collider (FCC-ee). The time-domain calculations of steady-state beam loading are presented and compared with frequency-domain analysis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Instabilities After Injection to the LHC

163

H. Timko, T. Argyropoulos, I. Karpov, E.N. Shaposhnikova
CERN, Geneva, Switzerland

Long-lasting phase oscillations have been observed at injection into the LHC since its first start-up with beam. These oscillations, however, were not leading to noticeable losses or blow-up in operation, and were therefore not studied in detail. In 2017, dedicated measurements with high-intensity bunches revealed that oscillations can lead to losses even slightly below the baseline intensity for the high-luminosity upgrade of the LHC. For the first time, high-resolution bunch profile acquisitions were triggered directly at injection and the formation of large-amplitude non-rigid dipole oscillations was observed on a turn-by-turn basis. First simulations can reproduce this instability via bunch filamentation that takes place after injection, depending on the mismatch between the bunch and bucket size in momentum at injection.

Slides TUP1WA03 [2.166 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP1WA03

Export •

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

WEP2PO003

Beam Loading and Longitudinal Stability Evaluation for the FCC-ee Rings

266

I. Karpov, P. Baudrenghien
CERN, Geneva, Switzerland

In high-current accelerators, interaction of the beam with fundamental impedance of the accelerating cavities can limit machine performance. It can result in a significant variation of bunch-by-bunch parameters (bunch length, synchronous phase, etc.) and lead to longitudinal coupled-bunch instability. In this work, these limitations are analysed together with possible cures for the high-current option (Z machine) of the future circular electron-positron collider (FCC-ee). The time-domain calculations of steady-state beam loading are presented and compared with frequency-domain analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO003

Export •

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