CERN Yellow Reports, Vol 4 (2016): Updated Baseline for a staged Compact Linear Collider

Two 6 t beam dumps, made of a graphite core encapsulated in a stainless steel vessel, are used to absorb the energy of the two Large Hadron Collider (LHC) intense proton beams during operation of the accelerator. Operational issues started to appear in 2015 during LHC Run 2 (2014–2018) as a consequence of the progressive increase of the LHC beam kinetic energy, necessitating technical interventions in the highly radioactive areas around the dumps. Nitrogen gas leaks appeared after highly energetic beam impacts and instrumentation measurements indicated an initially unforeseen movement of the dumps. A computer modelling analysis campaign was launched to understand the origin of these issues, including both Monte Carlo simulations to model the proton beam interaction as well as advanced thermo-mechanical analyses. The main ﬁndings were that the amount of instantaneous energy deposited in the dump vessel leads to a strong dynamic response of the whole dump and high accelerations (above 200 g). Based on these ﬁndings, an upgraded design, including a new support system and beam windows, was implemented to ensure the dumps' compatibility with the more intense beams foreseen during LHC Run 3 (2022–2025) of 539 MJ per beam. In this paper an integral overview of the operational behaviour of the dumps and the upgraded configurations are discussed.

Section: Jinst 16 P11019mentioning

confidence: 99%

Design and behaviour of the Large Hadron Collider external beam dumps capable of receiving 539 MJ/dump

Maestre¹,

Cabanilles²,

Kershaw³

et al. 2021

“…CLIC is a proposed linear electron-positron collider [14][15][16] at CERN. To produce high luminosities, linear colliders rely on ultra-small beam sizes at the interaction point.…”

Section: The Clic Final-focus Systemmentioning

confidence: 99%

Surrogate modeling of the CLIC final-focus system using artificial neural networks

OEgren¹,

Gohil²,

Schulte³

2021

Artificial neural networks can be used for creating surrogate models that can replace computationally expensive simulations. In this paper, a surrogate model was created for a subset of the Compact Linear Collider (CLIC) final-focus system. By training on simulation data, we created a model that maps sextupole offsets to luminosity and beam sizes, thus replacing computationally intensive tracking and beam-beam simulations. This model was then used for optimizing the parameters of a random walk procedure for sextupole alignment.

“…The detailed investigation of the properties of the Higgs boson has been identified as the highest priority for particle physics beyond the exploitation of the potential of the High-Luminosity LHC. The best precision for many observables can be obtained in electron-positron collisions, for which a number of different collider options have been proposed: on the one hand linear colliders, such as the ILC [1], which is under political consideration in Japan, or CLIC [2][3][4][5], and on the other hand circular colliders such as FCC-ee [6] or CEPC [7,8].…”

Section: Introductionmentioning

confidence: 99%

Design, construction and commissioning of a technological prototype of a highly granular SiPM-on-tile scintillator-steel hadronic calorimeter

White,

Yu,

Eigen

et al. 2023

The CALICE collaboration is developing highly granular electromagnetic and hadronic calorimeters for detectors at future energy frontier electron-positron colliders. After successful tests of a physics prototype, a technological prototype of the Analog Hadron Calorimeter has been built, based on a design and construction techniques scalable to a collider detector. The prototype consists of a steel absorber structure and active layers of small scintillator tiles that are individually read out by directly coupled SiPMs. Each layer has an active area of 72 × 72 cm^2 and a tile size of 3 × 3 cm^2. With 38 active layers, the prototype has nearly 22,000 readout channels, and its total thickness amounts to 4.4 nuclear interaction lengths. The dedicated readout electronics provide time stamping of each hit with an expected resolution of about 1 ns. The prototype was constructed in 2017 and commissioned in beam tests at DESY. It recorded muons, hadron showers and electron showers at different energies in test beams at CERN in 2018. In this paper, the design of the prototype, its construction and commissioning are described. The methods used to calibrate the detector are detailed, and the performance achieved in terms of uniformity and stability is presented.