arXiv subjects

J. Uythoven

Publications and source records attributed to J. Uythoven.

4 recordsLinked to original sources

arXiv2020

Fast Failures in the LHC and the future High Luminosity LHC*

An energy of $362\:\text{MJ}$ is stored in each of the two LHC proton beams for nominal beam parameters. This will be further increased to about $700\:\text{MJ}$ in the future High Luminosity LHC (HL-LHC) and uncontrolled beam losses represent a significant hazard for the integrity and safe operation of the machine. In this paper, a number of failure mechanisms that can lead to a fast increase of beam losses are analyzed. Most critical are failures in the magnet protection system, namely the quench heaters and a novel protection system called Coupling-Loss Induced Quench (CLIQ). An important outcome is that magnet protection has to be evaluated for its impact on the beam and designed accordingly. In particular, CLIQ, which is to protect the new HL-LHC triplet magnets, constitutes the fastest known failure in the LHC if triggered spuriously. A schematic change of CLIQ to mitigate the hazard is presented. A loss of the Beam-Beam Kick due to the extraction of one beam is another source of beam losses with a fast onset. A significantly stronger impact is expected in the upcoming LHC Run III and HL-LHC as compared to the current LHC, mainly due to the increased bunch intensity. Its criticality and mitigation methods are discussed. It is shown that symmetric quenches in the superconducting magnets for the final focusing triplet can have a significant impact on the beam on short timescales. The impact on the beam due to failures of the Beam-Beam Compensating Wires as well as coherent excitations by the transverse beam damper are also discussed.

physics.acc-ph↗

arXiv2017

Injection and Dumping Systems

Chapter 14 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report. The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.

physics.acc-ph↗

arXiv2014

Upgrades Of the SPS, Transfer Line and LHC Injection Protection Devices For the HL-LHC Era

The challenging High Luminosity LHC (HL-LHC) beam requirements will lead in the future to unprecedented beam parameters along the LHC injector chain. In the SPS accelerator these requests translate into about a factor two higher intensity and brightness than the present design performance. In addition to the challenge of producing and accelerating such beams, these parameters affect the resistance of the existing equipment against beam impact. Most of the protection devices in the SPS ring, its transfer lines and the LHC injection areas will be put under operational constraints which are beyond their design specification. The equipment concerned has been reviewed and their resistance to the HL-LHC beams checked. Theoretical and simulation studies have been performed for the SPS beam scraping system, the protection devices and the dump absorbers of the SPS-to-LHC transfer lines, as well as for the LHC injection protection devices. The first results of these studies are reported, together with the future prospects.

physics.acc-ph↗

arXiv2011

Injection and dump considerations for a 16.5 TeV HE-LHC

Injection and beam dumping is considered for a 16.5 TeV hadron accelerator in the current LHC tunnel, with an injection energy in the range 1 - 1.3 TeV. The present systems are described and the possible upgrade scenarios investigated for higher beam rigidity. In addition to the required equipment performance, the machine protection related aspects are explored. The expected constraints on the machine layout are also given. The technological challenges for the different equipment subsystems are detailed, and areas where R&D is necessary are highlighted.

physics.acc-ph↗