IPAC2017 - List of Authors (Pellegrini, D.)

Paper	Title	Page
TUPVA009	Multiparametric Response of the LHC Dynamic Aperture in Presence of Beam-Beam Effects	2051
	D. Pellegrini, F. Antoniou, S.D. Fartoukh, G. Iadarola, Y. Papaphilippou CERN, Geneva, Switzerland
	We performed extended simulations of LHC dynamic aperture (DA) in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: tunes, optics, bunch intensity, crossing angle, emittance, chromaticity and current in the Landau octupoles. Here we present a summary of these studies, giving an overview of the amplitude of the LHC operational space and pointing out the remaining margins for mitigation of instabilities. These studies supported the actions deployed during the 2016 run of the LHC, which aimed at maximising its performances. Examples of such actions are the switch to lower emittance beams, the reduction of crossing angle and tune trims. More recently, DA scans have been used to help the definition of the operational scenarios for the 2017 run. Additional room for improvements, for instance by deploying crossing angle levelling, will be explained.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA009
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TUPVA010	Multiparametric Response of the HL-LHC Dynamic Aperture in Presence of Beam-Beam Effects	2055
	D. Pellegrini, S.D. Fartoukh, N. Karastathis, Y. Papaphilippou CERN, Geneva, Switzerland
	We performed extended simulations of HL-LHC dynamic aperture in the presence of beam-beam effects in the weak- strong approximation, evaluating the contributions of param- eters such as: bunch intensity, crossing angle, chromaticity, current in the Landau octupoles and multipole errors. From the beam dynamics point of view, the main differ- ence between the LHC (until 2017) and the HL-LHC is the deployment of the achromatic telescopic squeezing (ATS) optics, allowing not only for a smaller '' reach, but also modifying the phase advances between the lattice correctors (sextupoles, octupoles) and the main IPs, and increasing the peak ' functions in the arcs. These correctors become therefore more efficient for the chromatic correction, but also a mitigation of the beam-beam long range interactions using the Landau octupoles is enabled, resulting in a possible reduction of the normalised crossing angle. The limits have been investigated in a tracking simulation campaign aimed at exploring the operational space for the HL-LHC and two possible options for luminosity levelling.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA010
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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

Multiparametric Response of the LHC Dynamic Aperture in Presence of Beam-Beam Effects

2051

D. Pellegrini, F. Antoniou, S.D. Fartoukh, G. Iadarola, Y. Papaphilippou
CERN, Geneva, Switzerland

We performed extended simulations of LHC dynamic aperture (DA) in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: tunes, optics, bunch intensity, crossing angle, emittance, chromaticity and current in the Landau octupoles. Here we present a summary of these studies, giving an overview of the amplitude of the LHC operational space and pointing out the remaining margins for mitigation of instabilities. These studies supported the actions deployed during the 2016 run of the LHC, which aimed at maximising its performances. Examples of such actions are the switch to lower emittance beams, the reduction of crossing angle and tune trims. More recently, DA scans have been used to help the definition of the operational scenarios for the 2017 run. Additional room for improvements, for instance by deploying crossing angle levelling, will be explained.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA009

Export •

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

TUPVA010

Multiparametric Response of the HL-LHC Dynamic Aperture in Presence of Beam-Beam Effects

2055

D. Pellegrini, S.D. Fartoukh, N. Karastathis, Y. Papaphilippou
CERN, Geneva, Switzerland

We performed extended simulations of HL-LHC dynamic aperture in the presence of beam-beam effects in the weak- strong approximation, evaluating the contributions of param- eters such as: bunch intensity, crossing angle, chromaticity, current in the Landau octupoles and multipole errors. From the beam dynamics point of view, the main differ- ence between the LHC (until 2017) and the HL-LHC is the deployment of the achromatic telescopic squeezing (ATS) optics, allowing not only for a smaller '' reach, but also modifying the phase advances between the lattice correctors (sextupoles, octupoles) and the main IPs, and increasing the peak ' functions in the arcs. These correctors become therefore more efficient for the chromatic correction, but also a mitigation of the beam-beam long range interactions using the Landau octupoles is enabled, resulting in a possible reduction of the normalised crossing angle. The limits have been investigated in a tracking simulation campaign aimed at exploring the operational space for the HL-LHC and two possible options for luminosity levelling.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA010

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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)