Publications related to Storage ring

Impact of beam-coupling impedance on the Schottky spectrum of bunched beam

Tatiana Pieloni, Nicolas Frank Mounet, Christophe Emmanuel R. Lannoy

The Schottky monitors of the Large Hadron Collider (LHC) can be used for non-invasive beam diagnostics to estimate various bunch characteristics, such as tune, chromaticity, bunch profile or synchrotron frequency distribution. However, collective effects, ...

Iop Publishing Ltd2024

Hosing of a Long Relativistic Particle Bunch in Plasma

Ambrogio Fasoli, Ivo Furno, Patrick Blanchard, Yanis Andrebe, Riccardo Agnello, Christine Stollberg, Sun Hee Kim, Alban Sublet, Shuai Liu

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, selfmodulation in the perpendicular plane, at frequencies clo ...

Amer Physical Soc2024

Characterization of Transverse Instabilities Driven by Electron Cloud

Sofia Carolina Johannesson

Electron cloud continues to be one of the main limiting factors of the Large Hadron Collider (LHC), the biggest accelerator at CERN. These clouds form in the beam chamber when positively charged particles are passing through and cause unwanted effects in b ...

EPFL2024

Development of the self-modulation instability of a relativistic proton bunch in plasma

Ambrogio Fasoli, Ivo Furno, Patrick Blanchard, Yanis Andrebe, Riccardo Agnello, Christine Stollberg, Sun Hee Kim, Ana Francisca Leal Silva Soares, Alban Sublet, Samuel Rey-Mermet, Shuai Liu

Self-modulation is a beam-plasma instability that is useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing the ratio between the initial transverse size ...

2023

Design and Development of a Diagnostic System for a Non-Intercepting Direct Measure of the SPIDER Ion Source Beamlet Current

Stable and uniform beams with low divergence are required in particle accelerators; therefore, beyond the accelerated current, measuring the beam current spatial uniformity and stability over time is necessary to assess the beam performance, since these pa ...

MDPI2023

Design, prototyping, and thermo-mechanical modelling of a neutron spallation target impacted by high-energy proton-beam pulses in the n_TOF facility at CERN

Raffaele Esposito

This manuscript describes the design work and the R&D activities carried out for the third-generation neutron production target in the neutron Time-Of-Flight (n_TOF) facility at the European Laboratory for Particle Physics (CERN). The facility is composed ...

EPFL2022

Description of beam instabilities in synchrotrons with wakefields and space charge forces using the circulant matrix model

Xavier Buffat, Tatiana Pieloni, Adrian Oeftiger

A new model for the description of beam instabilities in synchrotrons featuring wakefields and space charge forces is proposed, using the circulant matrix approach. The predictions of this model are discussed in light of past ones, with a particular emphas ...

2021

Gigahertz Frame Rate Imaging of Charge-Injection Dynamics in a Molecular Light Source

Klaus Kern, Markus Etzkorn, Anna Maria Roslawska, Abhishek Grewal

Light sources on the scale of single molecules can be addressed and characterized at their proper sub-nanometer scale by scanning tunneling microscopy-induced luminescence (STML). Such a source can be driven by defined short charge pulses while the lumines ...

AMER CHEMICAL SOC2021

Negative hydrogen ion dynamics inside the plasma volume of a linear device: Estimates from particle-in-cell calculations

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello

Negative hydrogen or deuterium ions are the precursor particles used to generate a high power beam of neutrals in order to heat the tokamak plasma core of magnetic fusion devices, inject current, and to some extent control instabilities. In the case of ITE ...

2021

Electron flux and pressure dynamic in the LHC vacuum pilot sector as a function of beam parameters and beam pipe properties

Ambrogio Fasoli, Elena Buratin, Vincent Baglin

The Large Hadron Collider (LHC) is affected by the electron cloud (EC) phenomenon that can provoke beam instabilities, detrimental heat loads and pressure increases in the vacuum system. An innovative dedicated system called vacuum pilot sector (VPS) provi ...

2020

Electron Cloud and Synchrotron Radiation characterization of technical surfaces with the Large Hadron Collider Vacuum Pilot Sector

Elena Buratin

This PhD thesis presents the experimental study on electron cloud (EC) and synchrotron radiation (SR) phenomena affecting the LHC storage ring performance. These phenomena are one of the major issues of the LHC storage ring, generating beam instabilities, ...

EPFL2020

Helical beam screen for the Future Circular Collider for hadrons injection kicker magnets

Agnieszka Chmielinska

The Future Circular Collider for hadrons (FCC-hh) is the proposed high-energy frontier particle collider, which is expected to enable proton-proton collisions at a center-of-mass energy of 100 TeV. The specifications for the FCC-hh injection kicker system ...

2020

Modeling of Quench Protection Concepts for Canted-Cosine-Theta Type High-Field Magnets

Andreas Pautz, Bernhard Auchmann, Jiani Gao

An innovative high-field superconducting magnet of Canted-Cosine-Theta (CCT) type has been proposed for Future Circular Collider 16 T dipole magnet design. The unique mechanical structure intercepts the accumulated forces lowering the stress on the winding ...

IEEE Institute of Electrical and Electronics Engineers2020

Loss of transverse Landau damping by noise and wakefield driven diffusion

Xavier Buffat, Sondre Vik Furuseth

Landau damping of coherent modes is strongly dependent on the exact shape of the particle bunches. One often assumes that the transverse distributions in high-energy hadron colliders can be approximated by Gaussian distributions, in acceptable agreement wi ...

2020

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

Gennady Plyushchev, Yiming Li, Sijie Liu, Michele Marin, Sun Hee Kim, Ishkhan Gorgisyan, Shuai Liu

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1 x 10(14) and 7.7 x 10(14) electrons/cm(3). We show that these wakefields periodically defocus the proton bunch itself, consistently with t ...

2019

Optimization of the Beam Screen for the FCC Injection Kicker Magnets

Agnieszka Chmielinska

The Future Circular Collider for hadrons (FCC-hh) is a proposed high-energy frontier particle accelerator, which would be built in a new ~100 km circumference tunnel and would enable proton-proton collisions at a centre-of-mass energy of 100 TeV. The basel ...

EPFL2019

Noninvasive LHC transverse beam size measurement using inelastic beam-gas interactions

Olivier Schneider, Aurelio Bay, Guido Haefeli, Frédéric Blanc, Tatsuya Nakada, Mark Tobin, Zhirui Xu, Sebastiana Gianì, Plamen Hristov Hopchev, Olivier Göran Girard, Axel Kuonen, Louise Helene Soegaard Jensen, Massimo Giovannozzi

The beam-gas vertex (BGV) detector is an innovative instrument measuring noninvasively the transverse beam size in the Large Hadron Collider (LHC) using reconstructed tracks from beam-gas interactions. The BGV detector was installed in 2016 as part of the ...

2019

New spiral beam screen design for the FCC-hh injection kicker magnet

Agnieszka Chmielinska

The injection kicker system for the Future Circular Collider (FCC-hh) must satisfy demanding requirements. To achieve low pulse ripple and fast field rise and fall times, the injection system will use ferrite loaded transmission line type magnets. The beam ...

IOP PUBLISHING LTD2019

Possible Mitigations of Longitudinal Intensity Limitations for HL-LHC Beam in the CERN SPS

Joël Repond

The Super Proton Synchrotron (SPS) at CERN is the injector of the Large Hadron Collider (LHC), the world's largest particle collider. The High-Luminosity LHC (HL-LHC) project is a major step forward in the improvement of the LHC performances and it require ...

EPFL2019

A novel approach to Landau damping of transverse collective instabilities in future hadron colliders

Michael Schenk

Transverse collective instabilities induced by the beam-coupling impedance of the accelerator structure lead to beam quality degradation and pose a major limitation to the machine performance. Landau damping, a powerful stabilising mechanism that can be em ...

EPFL2019