Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

Mirarchi, Daniele; Appleby, R. B.; Bruce, Roderik; Giovannozzi, M.; Mereghetti, Alessio; Redaelli, Stefano; Stancari, G.

doi:10.1140/epjp/s13360-021-02201-5

Cited by 5 publications

(13 citation statements)

References 44 publications

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“…The presence of highly populated beam tails risks making the operation very sensitive to small orbit jitters, naturally observed in the beam dynamics or triggered by different sources like earth quakes and power converter ripple [22]. Damage might also be caused in case of fast failure scenarios as potentially expected at the HL-LHC.…”

Section: Motivations and Required Performancementioning

confidence: 99%

“…Furthermore, it is planned to bias the electrodes at the entrance of the collector, to reduce the energy deposited to the collector, the secondary electron emission (therefore maximizing the electron efficiency) and the gas induced desorption (to guarantee best vacuum performance). Engineering margins on the design are being finalized, taking into account that the duty factor in operation might be significantly lower than unity for several considered powering schemes [40] and that the possibility to add a bias voltage to decelerate the electron beam before it reaches the collector is planned.…”

Section: Jinst 16 P03042mentioning

confidence: 99%

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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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Section: Motivations and Required Performancementioning

confidence: 99%

Section: Jinst 16 P03042mentioning

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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“…Therefore, ATLAS requested that the luminosity be kept constant for the first few hours of a run (luminosity-levelling) at a luminosity of 1.56 × 10 34 cm −2 s −1 with a pile-up of 60. In 2018, the LHC switched back to the 25 ns BCMS beam for luminosity production, as the problems with beam losses in 16L2 were mitigated [34], and the pile-up interactions were again reduced to about 60. More information about these filling schemes can be found in ref.…”

Section: Lhc Fill Patterns In Runmentioning

confidence: 99%

Operation of the ATLAS trigger system in Run 2

Aad

Abbott²,

Abbott³

et al. 2020

J. Inst.

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Large Hadron Collider employs a two-level trigger system to record data at an average rate of 1 kHz from physics collisions, starting from an initial bunch crossing rate of 40 MHz. During the LHC Run 2 (2015-2018), the ATLAS trigger system operated successfully with excellent performance and flexibility by adapting to the various run conditions encountered and has been vital for the ATLAS Run-2 physics programme. For protonproton running, approximately 1500 individual event selections were included in a trigger menu which specified the physics signatures and selection algorithms used for the data-taking, and the allocated event rate and bandwidth. The trigger menu must reflect the physics goals for a given data collection period, taking into account the instantaneous luminosity of the LHC and limitations from the ATLAS detector readout, online processing farm, and offline storage. This document discusses the operation of the ATLAS trigger system during the nominal proton-proton data collection in Run 2 with examples of special data-taking runs. Aspects of software validation, evolution of the trigger selection algorithms during Run 2, monitoring of the trigger system and data quality as well as trigger configuration are presented.

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“…Contributions to this issue represent and attempt to cover a broad domain of topics in beam physics, with a loose classification into three categories of advances, challenges, and applications. References [13][14][15][16][17][18][19][20][21] provide a global overview of the applications of advanced beam dynamics concepts to existing or future machines. The nonlinear beam dynamics combined with the use of electron lenses has been considered in the framework of the High-Luminosity LHC Project and discussed in [21].…”

mentioning

confidence: 99%

“…References [13][14][15][16][17][18][19][20][21] provide a global overview of the applications of advanced beam dynamics concepts to existing or future machines. The nonlinear beam dynamics combined with the use of electron lenses has been considered in the framework of the High-Luminosity LHC Project and discussed in [21]. Various techniques devised to measure the available beam aperture in the LHC, which contributed to the astonishing performance reached during Run 2, are presented in [20].…”

mentioning

confidence: 99%

Focus point on high-energy accelerators: advances, challenges, and applications

et al. 2023

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Particle accelerators are unique scientific tools that offer unrivalled energy per constituent of their charged particle beams compared to sources normally available in laboratories. Focused high-density beams of electrons, positrons, protons, antiprotons, ions, and other elementary particles are used. Since the early twentieth century, accelerators have been widely applied to physics research, and great progress in science and technology has been driven by the development of more and more powerful accelerators needed for fundamental physics research [1].Circular accelerators, and specifically colliders, occupy a special place [2, 3] among particle accelerator facilities. These innovative scientific tools allowed fundamental advances in scientific discoveries in high-energy physics. Collider technology and beam physics have advanced greatly, and modern facilities are now operating with energy and luminosity of several orders of magnitude higher than those of pioneer colliders in the early 1960s.Analysis of all Nobel Prize-winning physics research since 1939 [4] reveals that accelerators have played an integral role in influencing more than a quarter of physics prize recipients by either inspiring them or facilitating their research. Moreover, accelerators have contributed on average to one Nobel Prize in physics per three years [5], and four Nobel Prizes directly recognised breakthroughs in accelerator science and technology. Physics, however, is not the only domain of science to profit from the use of particle accelerators. Notably, synchrotron radiation sources based on accelerators have recently been instrumental in a number of Nobel Prize-winning research achievements in chemistry and biology. Nuclear physics is another field that has benefited from the progress made by particle accelerators [6].According to recent data [7], currently about 140 accelerators of all types are devoted to fundamental research, while in 2012 the

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Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

Cited by 5 publications

References 44 publications

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

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

Operation of the ATLAS trigger system in Run 2

Focus point on high-energy accelerators: advances, challenges, and applications

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