IBIC2023 - List of Keywords (betatron)

Paper	Title	Other Keywords	Page
TU3C03	Collimator Scan Based Beam Halo Measurements in LHC and HL-LHC	luminosity, emittance, operation, collimation	164
	P.D. Hermes, M. Giovannozzi, C.E. Montanari, S. Morales Vigo, S. Redaelli, B. Salvachúa CERN, Meyrin, Switzerland M. Rakic EPFL, Lausanne, Switzerland
	Measurements in the CERN Large Hadron Collider (LHC) have indicated that the population of the transverse beam halo is greater than that of a Gaussian distribution. With the upcoming High Luminosity upgrade (HL-LHC), the stored beam energy in the beam halo could become large enough to threaten the integrity of the collimation system. Considerable efforts during the ongoing LHC Run 3 are dedicated to characterising the transverse beam halo, and its diffusion properties, after the LHC Injector Upgrade (LIU) in preparation for HL-LHC operation. Given the unprecedented stored beam energies of about 400MJ, presently achieved at the LHC, and about 700MJ planned at the HL-LHC, conventional measurements are difficult. Halo and diffusion measurements are currently based on collimator scans, where robust collimators are inserted in steps into the circulating beam halo. In this contribution, we present techniques for halo characterisation employed in LHC and compare results obtained from such measurements in LHC Run 2 and the ongoing LHC Run 3. We present plans for measurements in the remainder of LHC Run 3 and describe expected challenges for halo quantification in HL-LHC.
	Slides TU3C03 [5.876 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C03
About •	Received ※ 05 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 12 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP035	Statistical Properties of Schottky Spectra	simulation, synchrotron, dipole, diagnostics	433
	C. Lannoy, D. Alves, K. Łasocha, N. Mounet CERN, Meyrin, Switzerland C. Lannoy, T. Pieloni EPFL, Lausanne, Switzerland
	Schottky signals are used for non-invasive beam diagnostics as they contain information on various beam and machine parameters. The instantaneous Schottky signal is, however, only a single realisation of a random process, implicitly depending on the discrete distribution of synchrotron and betatron amplitudes and phases among the particles. To estimate the expected value of the Schottky power spectrum, and reveal the inner structure of the Bessel satellites described by the theory, the averaging of instantaneous Schottky spectra is required. This study describes this procedure quantitatively by analysing the statistical properties of the Schottky signals, including the expected value and variance of Schottky power spectra. Furthermore, we investigate how these quantities evolve with the number of particles in the bunch, the observed harmonic of the revolution frequency, the distribution of synchrotron oscillation amplitudes, and the bunch profile. The theoretical findings are compared against macro-particle simulations as well as Monte Carlo computations.
	Poster WEP035 [3.908 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP035
About •	Received ※ 05 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TH2C03	Analysis of the Transverse Schottky Signals in the LHC	synchrotron, diagnostics, octupole, impedance	462
	K. Łasocha, D. Alves CERN, Meyrin, Switzerland
	Schottky-based diagnostics are remarkably useful tools for the non-invasive monitoring of hadron beam and machine characteristics such as the betatron tune and the chromaticity. In this contribution recent developments in the analysis of the transverse Schottky signals measured at the Large Hadron Collider will be reported. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and benchmarked with respect to the previously known methods and alternative diagnostic.
	Slides TH2C03 [4.054 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TH2C03
About •	Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 19 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TU3C03

Collimator Scan Based Beam Halo Measurements in LHC and HL-LHC

luminosity, emittance, operation, collimation

164

P.D. Hermes, M. Giovannozzi, C.E. Montanari, S. Morales Vigo, S. Redaelli, B. Salvachúa
CERN, Meyrin, Switzerland
M. Rakic
EPFL, Lausanne, Switzerland

Measurements in the CERN Large Hadron Collider (LHC) have indicated that the population of the transverse beam halo is greater than that of a Gaussian distribution. With the upcoming High Luminosity upgrade (HL-LHC), the stored beam energy in the beam halo could become large enough to threaten the integrity of the collimation system. Considerable efforts during the ongoing LHC Run 3 are dedicated to characterising the transverse beam halo, and its diffusion properties, after the LHC Injector Upgrade (LIU) in preparation for HL-LHC operation. Given the unprecedented stored beam energies of about 400MJ, presently achieved at the LHC, and about 700MJ planned at the HL-LHC, conventional measurements are difficult. Halo and diffusion measurements are currently based on collimator scans, where robust collimators are inserted in steps into the circulating beam halo. In this contribution, we present techniques for halo characterisation employed in LHC and compare results obtained from such measurements in LHC Run 2 and the ongoing LHC Run 3. We present plans for measurements in the remainder of LHC Run 3 and describe expected challenges for halo quantification in HL-LHC.

Slides TU3C03 [5.876 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C03

About •

Received ※ 05 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 12 September 2023

Cite •

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

WEP035

Statistical Properties of Schottky Spectra

simulation, synchrotron, dipole, diagnostics

433

C. Lannoy, D. Alves, K. Łasocha, N. Mounet
CERN, Meyrin, Switzerland
C. Lannoy, T. Pieloni
EPFL, Lausanne, Switzerland

Schottky signals are used for non-invasive beam diagnostics as they contain information on various beam and machine parameters. The instantaneous Schottky signal is, however, only a single realisation of a random process, implicitly depending on the discrete distribution of synchrotron and betatron amplitudes and phases among the particles. To estimate the expected value of the Schottky power spectrum, and reveal the inner structure of the Bessel satellites described by the theory, the averaging of instantaneous Schottky spectra is required. This study describes this procedure quantitatively by analysing the statistical properties of the Schottky signals, including the expected value and variance of Schottky power spectra. Furthermore, we investigate how these quantities evolve with the number of particles in the bunch, the observed harmonic of the revolution frequency, the distribution of synchrotron oscillation amplitudes, and the bunch profile. The theoretical findings are compared against macro-particle simulations as well as Monte Carlo computations.

Poster WEP035 [3.908 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-WEP035

About •

Received ※ 05 September 2023 — Accepted ※ 14 September 2023 — Issue date ※ 29 September 2023

Cite •

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

TH2C03

Analysis of the Transverse Schottky Signals in the LHC

synchrotron, diagnostics, octupole, impedance

462

K. Łasocha, D. Alves
CERN, Meyrin, Switzerland

Schottky-based diagnostics are remarkably useful tools for the non-invasive monitoring of hadron beam and machine characteristics such as the betatron tune and the chromaticity. In this contribution recent developments in the analysis of the transverse Schottky signals measured at the Large Hadron Collider will be reported. A fitting-based technique, where the measured spectra are iteratively compared with theoretical predictions, will be presented and benchmarked with respect to the previously known methods and alternative diagnostic.

Slides TH2C03 [4.054 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TH2C03

About •

Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 19 September 2023

Cite •

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