Measured and simulated heavy-ion beam loss patterns at the CERN Large Hadron Collider

Hermes, Pascal; Bruce, Roderik; Jowett, John; Redaelli, Stefano; Ferrando, B. Salvachua; Valentino, Gianluca; Wollmann, Daniel

doi:10.1016/j.nima.2016.02.050

Cited by 23 publications

(18 citation statements)

References 11 publications

(22 reference statements)

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“…In this article we present predictions for HL-LHC losses during luminosity levelling, as well as measurements of the performance of the LHC collimation system during Run 1 and 2. Previously, studies of LHC collimation efficiency have been successfully performed using the * sam.tygier@manchester.ac.uk SixTrack code with comparisons to BLM data at fixed optical configurations [7][8][9][10][11][12][13][14][15]. These demonstrate that maps of proton loss locations are useful for evaluating collimation scenarios and as input to energy deposition studies using codes such as FLUKA [16].…”

Section: Introductionmentioning

confidence: 99%

Performance of the Large Hadron Collider cleaning system during the squeeze: Simulations and measurements

Tygier

Appleby

Bruce

et al. 2019

Phys. Rev. Accel. Beams

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The Large Hadron Collider (LHC) at CERN is a 7 TeV proton synchrotron, with a design stored energy of 362 MJ per beam. The high-luminosity (HL-LHC) upgrade will increase this to 675 MJ per beam. In order to protect the superconducting magnets and other sensitive equipment from quenches and damage due to beam loss, a multi-level collimation system is needed. Detailed simulations are required to understand where particles scattered by the collimators are lost around the ring in a range of machine configurations. Merlin++ is a simulation framework that has been extended to include detailed scattering physics, in order to predict local particle loss rates around the LHC ring. We compare Merlin++ simulations of losses during the squeeze (the dynamic reduction of the β-function at the interaction points before the beams are put into collision) with loss maps recorded during beam squeezes for Run 1 and 2 configurations. The squeeze is particularly important as both collimator positions and quadrupole magnet currents are changed. We can then predict, using Merlin++, the expected losses for the HL-LHC to ensure adequate protection of the machine.

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Section: Introductionmentioning

confidence: 99%

Performance of the Large Hadron Collider cleaning system during the squeeze: Simulations and measurements

Tygier

Appleby

Bruce

et al. 2019

Phys. Rev. Accel. Beams

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“…-18 - The HEL performance assessment relies on multi-turn tracking simulations carried out with SixTrack [42][43][44][45][46] that allows a symplectic, fully chromatic, and 6D tracking along the magnetic lattice of the machine, taking into account interactions with the ring collimators and the detailed aperture model of the entire ring. The code has been compared to LHC data in a number of studies [4,7,11,[47][48][49][50] with excellent agreement. HELs are integrated in the lattice as magnetic elements [51,52] and their effect on the beam can be modelled using different electron beam kicks (earlier studies can also be found in [53,54]).…”

Section: Expected Performancementioning

confidence: 99%

Hollow electron lenses for beam collimation at the High-Luminosity Large Hadron Collider (HL-LHC)

Redaelli¹,

Appleby²,

Bruce³

et al. 2021

J. Inst.

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Electrons lenses produce a high-intensity electron beam and have a variety of applications to circular hadron accelerators. Electron beams of different transverse cross sections and distributions may be designed, depending on the desired application, and they are produced and steered along the orbit of the hadron beam, overlapping with it for typical distances of a few meters before being deflected away and disposed of. Hollow electron beams find applications to high-intensity beam collimation for machines like the CERN Large Hadron Collider (LHC). Such devices can be integrated in a collimation system to improve the halo-cleaning performance through an active control of the halo dynamics: the annular distribution of the electrons excites resonantly the beam tails surrounding the beam core, while the core itself remains unperturbed, as ideally it only "sees" the field-free "hole" in the electron distribution. Hollow electron lenses are part of the upgrade baseline of the High-Luminosity project of the LHC (HL-LHC) and will be installed in the machine during a long shutdown in 2025-2027 to mitigate effects from beam losses so to improve the collimation system performance. This paper describes the hollow electron lens project within the HL-LHC collimation upgrade. K: Accelerator Applications; Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics); Accelerator Subsystems and Technologies; Beam dynamics Work supported by the HL-LHC project.

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“…Adapted with permission. [ 374 ] The separation between the beams is exaggerated here (in reality it is 20 cm). IP: interaction points.…”

Section: Colliding‐beam Opportunitiesmentioning

confidence: 99%

Expanding Nuclear Physics Horizons with the Gamma Factory

et al. 2022

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The Gamma Factory (GF) is an ambitious proposal, currently explored within the CERN Physics Beyond Colliders program, for a source of photons with energies up to ≈400 MeV and photon fluxes (up to ≈1017 photons s−1) exceeding those of the currently available gamma sources by orders of magnitude. The high‐energy (secondary) photons are produced via resonant scattering of the primary laser photons by highly relativistic partially‐stripped ions circulating in the accelerator. The secondary photons are emitted in a narrow cone and the energy of the beam can be monochromatized, down to 10−3–10−6 level, via collimation, at the expense of the photon flux. This paper surveys the new opportunities that may be afforded by the GF in nuclear physics and related fields.

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Measured and simulated heavy-ion beam loss patterns at the CERN Large Hadron Collider

Cited by 23 publications

References 11 publications

Performance of the Large Hadron Collider cleaning system during the squeeze: Simulations and measurements

Performance of the Large Hadron Collider cleaning system during the squeeze: Simulations and measurements

Hollow electron lenses for beam collimation at the High-Luminosity Large Hadron Collider (HL-LHC)

Expanding Nuclear Physics Horizons with the Gamma Factory

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