International Linear Collider
Not a member yet
509047 research outputs found
Sort by
CMS Public Newsletter - Point Cinq - February 2025
No full textThe first publicly available newsletter. February 2025
Optimisation of ATLAS computing resource usage through a modern HEP Benchmark Suite via HammerCloud and Big PanDA
No full textIn April 2023, HEPScore23, the new benchmark based on HEP specific applications, was adopted by WLCG, replacing HEP-SPEC06. As part of the transition to the new benchmark, the CPU corepower published by the sites needed to be compared with the effective power observed while running ATLAS workloads. One aim was to verify the conversion rate between the scores of the old and the new benchmark. The other objective was to understand how the HEPScore performs when run on multi-core job slots, so exactly like the computing sites are being used in the production environment. Our study leverages the HammerCloud infrastructure and the PanDA Workload Management System to collect a large benchmark statistic across 136 computing sites using an enhanced HEP Benchmark Suite. It allows us to collect not only performance metrics, but, thanks to plugins, it also collects information such as machine load, memory usage and other user-defined metrics during the execution and stores it in an OpenSearch database. These extensive tests allow for an in-depth analysis of the actual, versus declared computing capabilities of these sites. The results provide valuable insights into the real-world performance of computing resources pledged to ATLAS, identifying areas for improvement while spotlighting sites that underperform or exceed expectations. Moreover, this helps to ensure efficient operational practices across sites. The collected metrics allowed us to detect and fix configuration issues and therefore improve the experienced performance
Accelerating Berends-Giele recursion for gluons in arbitrary dimensions over finite fields
No full textThis work provides a proof of concept for the computation of pure gluonic amplitudes in quantum chromodynamics (QCD) on graphics processing units (GPUs). The implementation relies on the Berends-Giele recursion algorithm and, for the first time on a GPU, enables the numerical computation of amplitudes in an arbitrary number of space-time dimensions and over finite fields. This demonstrates the advantages of hardware acceleration, not only for the computation of tree-level amplitudes for real-radiation processes in four dimensions over complex numbers but also for generating loop integrands for virtual corrections in dimensions over finite fields. The associated computer program is publicly available
Visit by Professor Birgitta Wolff, Rector, University of Wuppertal, Germany
No full textVisit by Professor Birgitta Wolff, Rector, University of Wuppertal, Federal Republic of German
Rule-based solutions in DAQ Controls
No full textOverview of different approaches and technologies for building ruls-based systems for automated intelligence assisting DAQ operations: .automation, error handling, recovery, diagnostics, shifter guidance
Measurement of isolated prompt photon production in pp and p–Pb collisions at the LHC
No full textThis paper presents the measurement of the isolated prompt photon inclusive production cross section in pp and p-Pb collisions by the ALICE Collaboration at the LHC. The measurement is performed in p-Pb collisions at centre-of-mass energies per nucleon pair of TeV and TeV, as well as in pp collisions at TeV and TeV. The cross section is obtained at mid-rapidity GeV/. However, deviations from unity ( GeV/. However, deviations from unity () of up to 20% are observed for GeV/ with limited significance, indicating the possible presence of nuclear effects in the initial state of the collision. The suppression increases with decreasing with a significance of for a non-zero slope and yields with a significance of at TeV for GeV/. In addition, a significance of is observed for at the lower collision energy TeV for GeV/. The magnitude and shape of the suppression are consistent with pQCD predictions at NLO using nPDFs that incorporate nuclear shadowing effects in the Pb nucleus
Searches for Lepton Flavour and Number Violation and Hidden Sector Particles at NA62
No full textRare kaon decays are among the most sensitive probes of both heavy and light new physicsbeyond the Standard Model (SM) description thanks to high precision of the Standard Modelpredictions, availability of very large datasets, and the relatively simple decay topologies. TheNA62 experiment at CERN is a multi-purpose high-intensity kaon decay experiment, and carriesout a broad rare-decay and hidden-sector physics programme. Recent NA62 results on searchesfor violation of lepton flavour and lepton number in kaon decays, and searches for production inhidden-sector mediators in kaon decays, are presented. Future prospects of these searches arediscussed
Advancements in NbSn 12 T Cos-Theta Dipole Development for Next-Generation Accelerators: The INFN-CERN Collaboration on the FalconD Project
No full textResearch for next-generation accelerators necessitates the development of high-field bending dipoles, which are critical for achieving precise beam control and optimizing efficiency. Among the promising superconducting materials is NbSn, which has already demonstrated its effectiveness in accelerator magnets, such as the MQXF quadrupoles used in the high-luminosity upgrade of the LHC. In collaboration with CERN, the Genoa and Milan divisions of INFN are spearheading the development of a 12-T NbSn dipole model configured in a cos-theta geometry, known as FalconD (Future Accelerator post-LHC Cos-theta Optimised NbSn dipole). This ambitious project focuses on pushing the limits of magnetic field strength and stability. A crucial component of this effort is the fabrication of high-performance coils, a task entrusted to the Italian company ASG Superconductors. This contribution provides an in-depth overview of the project's design considerations, including the coil architecture, material selection, and key technological challenges. Additionally, it discusses the fabrication process, testing methodologies, and future prospects for implementing these advanced dipoles in next-generation particle accelerators
Conceptual Structural Design and Analysis of a 20 T Hybrid Cos Dipole for Future Particle Colliders
No full textTo reach high collision energy for future high-energy particle colliders, like the Future Circular Collider (FCC) or the Muon Collider, it is required to achieve high field strength of the bending dipoles. Currently, the practical limit for Nb Sn technology is around 16 T and, in order to further increase the magnetic field, the superconducting magnet community is considering High Temperature Superconductors (HTS), in particular Bi-2212 and REBCO conductors. However, their relevant higher cost has led the community to consider a hybrid approach where HTS materials are used in the high field region of the coils with so-called “insert coils”, and Low Temperature Superconductors are involved in the lower field part ( 16 T) with so-called “outsert coils”. This paper describes the conceptual mechanical design of a 20 T hybrid cos dipole configuration. The high stress levels that the structure is facing due to the high magnetic field are discussed. Moreover, it presents the results of the optimization analysis of the shell-based support structure based on the key-and-bladder technology that provides the azimuthal pre-stress during room temperature assembly and cooldown to cryogenic temperatures. The aim of this work is to present a feasible design that satisfies the stress requirements
Development of SLA 3D printed volumes for leak testing of LHC Hi-Lumi cryomodules at STFC
No full textDaresbury Laboratory recently completed the build of a Radio Frequency Dipole (RFD) crab cavity cryomodule for the Super Proton Synchrotron (SPS). During the build the team faced challenges leak testing welds which could not be tested in the typical evacuation method. Each cryomodule build requires 34 unique cryogenic and insulation vacuum weld configurations, most of which are repeated across multiple weld sites. Each weld must be qualified inspected and tested (visual and leak) before the build can progress. A suite of bespoke 3D printed weld test tools and procedures have been developed with major savings to time and cost and improved quality of leak testing tooling, developing a methodology which can be adapted to many different weld configurations. All whilst maintaining a baseline leak rate of <5e-12 mbar L/s at or below 1e-3 mbar. The result was a repeatable and cost-effective means of performing high-accuracy leak tests in a short timescale. •STFC has built its first cryomodule for the CERN LHC – High luminosity project.•SLA 3D printed plastic volumes are a cost-effective material for leak detection.•Using Accura25, volumes have been printed that reach 1E-03 – 1E-04 mbar.•Accura25 vol have been used to leak test with <5E-12 mbar l/s accuracy.•SLA parts perform equally to stainless steel during helium leak testing