IPAC2021 - List of Authors (Paraschou, K.)

Paper	Title	Page
TUXA03	Progress in Mastering Electron Clouds at the Large Hadron Collider	1273
	G. Iadarola, B. Bradu, L. Mether, K. Paraschou, V. Petit, G. Rumolo, L. Sabato, G. Skripka, M. Taborelli, L.J. Tavian CERN, Geneva, Switzerland K. Paraschou AUTH, Thessaloniki, Greece
	During the second operational run of the Large Hadron Collider (LHC) a bunch spacing of 25 ns was used for the first time for luminosity production. With such a spacing, electron cloud effects are much more severe than with the 50-ns spacing, which had been used in the previous run. Beam-induced conditioning of the beam chambers mitigated the e-cloud formation to an extent that allowed an effective exploitation of 25 ns beams. Nevertheless, even after years of conditioning, e-cloud effects remained very visible, affecting beam stability and beam quality, and generating strong heat loads on the beam screens of the superconducting magnets with puzzling features. In preparation for the High Luminosity LHC upgrade, remarkable progress has been made in the modeling of the e-cloud formation and of its influence on beam stability, slow losses and emittance blow up, as well as in the understanding of the underlying behavior of the beam-chamber surface. In this contribution, we describe the main experimental observations from beam operation, the outcome of laboratory analysis conducted on beam screens extracted after the run, and the main advancements in the modeling of these phenomena.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA03
About •	paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 29 August 2021
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THPAB190	Optimising and Extending a Single-Particle Tracking Library for High Parallel Performance	4146
	M. Schwinzerl, H. Bartosik, R. De Maria, G. Iadarola, K. Paraschou CERN, Geneva, Switzerland A. Oeftiger GSI, Darmstadt, Germany M. Schwinzerl KFUG/IMSC, Graz, Austria
	SixTrackLib is a library for performing beam-dynamics simulations on highly parallel computing devices such as shared memory multi-core processors or graphical processing units (GPUs). Its single-particle approach fits very well with parallel implementations with reasonable baseline performance, making such a library an interesting building block for various use cases, including simulations covering collective effects. We describe optimizations to improve their performance on SixTrackLib’s main target platforms and the associated performance gains. Finally, we outline the implemented technical interfaces and extensions that allow SixTrackLib to be used in a wider range of applications and studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB190
About •	paper received ※ 18 May 2021 paper accepted ※ 14 July 2021 issue date ※ 16 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Progress in Mastering Electron Clouds at the Large Hadron Collider

1273

G. Iadarola, B. Bradu, L. Mether, K. Paraschou, V. Petit, G. Rumolo, L. Sabato, G. Skripka, M. Taborelli, L.J. Tavian
CERN, Geneva, Switzerland
K. Paraschou
AUTH, Thessaloniki, Greece

During the second operational run of the Large Hadron Collider (LHC) a bunch spacing of 25 ns was used for the first time for luminosity production. With such a spacing, electron cloud effects are much more severe than with the 50-ns spacing, which had been used in the previous run. Beam-induced conditioning of the beam chambers mitigated the e-cloud formation to an extent that allowed an effective exploitation of 25 ns beams. Nevertheless, even after years of conditioning, e-cloud effects remained very visible, affecting beam stability and beam quality, and generating strong heat loads on the beam screens of the superconducting magnets with puzzling features. In preparation for the High Luminosity LHC upgrade, remarkable progress has been made in the modeling of the e-cloud formation and of its influence on beam stability, slow losses and emittance blow up, as well as in the understanding of the underlying behavior of the beam-chamber surface. In this contribution, we describe the main experimental observations from beam operation, the outcome of laboratory analysis conducted on beam screens extracted after the run, and the main advancements in the modeling of these phenomena.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA03

About •

paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 29 August 2021

Export •

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

THPAB190

Optimising and Extending a Single-Particle Tracking Library for High Parallel Performance

4146

M. Schwinzerl, H. Bartosik, R. De Maria, G. Iadarola, K. Paraschou
CERN, Geneva, Switzerland
A. Oeftiger
GSI, Darmstadt, Germany
M. Schwinzerl
KFUG/IMSC, Graz, Austria

SixTrackLib is a library for performing beam-dynamics simulations on highly parallel computing devices such as shared memory multi-core processors or graphical processing units (GPUs). Its single-particle approach fits very well with parallel implementations with reasonable baseline performance, making such a library an interesting building block for various use cases, including simulations covering collective effects. We describe optimizations to improve their performance on SixTrackLib’s main target platforms and the associated performance gains. Finally, we outline the implemented technical interfaces and extensions that allow SixTrackLib to be used in a wider range of applications and studies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB190

About •

paper received ※ 18 May 2021 paper accepted ※ 14 July 2021 issue date ※ 16 August 2021

Export •

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