LHC Upgrade (Phase II)

LHC Upgrade (Phase II)
Name	LHC Upgrade (Phase II)
Location	CERN
Status	Planned
Collaborators	ATLAS experiment, CMS experiment, LHCb experiment, ALICE experiment, European Organization for Nuclear Research

LHC Upgrade (Phase II)

The LHC Upgrade (Phase II) is a planned major enhancement of the Large Hadron Collider complex at CERN designed to substantially increase instantaneous luminosity and integrated luminosity for the principal experiments ATLAS experiment, CMS experiment, LHCb experiment, and ALICE experiment. It follows earlier improvement phases at the Large Hadron Collider and connects to broader accelerator development efforts such as the High-Luminosity Large Hadron Collider program and technology transfer initiatives involving institutions like Fermilab and DESY.

Overview

Phase II represents a continuation and deepening of work begun in the High-Luminosity LHC phase, integrating advanced superconducting magnet technology developed at Brookhaven National Laboratory, KEK, and Instituto Nazionale di Fisica Nucleare. The upgrade encompasses accelerator hardware, injector chain enhancements linked to the SPS and PS Booster, and comprehensive detector modernization at collaborations including ATLAS experiment and CMS experiment. Governance involves major stakeholders such as European Commission, national agencies like STFC and NSF, and consortia including CERN member states and observer partners like Japan and United States Department of Energy.

Motivation and Scientific Goals

Phase II aims to enable precision tests of the Standard Model of particle physics and searches for phenomena predicted by theories such as supersymmetry, extra dimensions, dark matter models, and composite Higgs scenarios. By targeting higher integrated luminosity, the project seeks improved sensitivity to rare processes like Higgs boson self-coupling measurements and top quark rare decays, while augmenting programmatic synergy with experiments at Belle II, Neutrino Oscillation facilities, and IceCube. Broader objectives include supporting analyses relevant to awards and recognitions in particle physics such as the Nobel Prize in Physics and fostering cross-disciplinary collaborations with institutions like European Space Agency and CERN Courier–related outreach.

Technical Upgrades and Accelerator Improvements

Key Phase II hardware targets include next-generation high-field superconducting quadrupoles based on niobium-tin developed in collaboration with University of Oxford, MIT, and PSI, energy-efficient cryogenic plants influenced by designs from ITER and LHCb upgrade experience, and advanced radio-frequency systems leveraging research from SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory. Injector chain upgrades coordinate with projects at the Proton Synchrotron and the Super Proton Synchrotron and interface with beam dynamics studies from Paul Scherrer Institute and École Polytechnique. Controls, timing, and machine protection adopt architectures inspired by European XFEL and ITER control systems, integrating diagnostics from Diamond Light Source and MAX IV Laboratory.

Detector Upgrades and Experimental Impacts

Detectors will receive major overhauls: pixel and tracking systems in ATLAS experiment and CMS experiment using silicon technologies from CERN Microelectronics, calorimeter front-ends optimized with contributions from IN2P3 and INFN, and trigger/DAQ architectures co-developed with Fermilab and TRIUMF. The LHCb experiment upgrade will enhance vertex resolution for flavour physics, complementing measurements at BaBar and Belle II, while ALICE experiment will expand heavy-ion capabilities with input from GSI Helmholtz Centre and Brookhaven National Laboratory. These improvements impact data analysis pipelines used by collaborations such as ATLAS collaboration and CMS collaboration and support theoretical interpretation from groups at CERN Theoretical Physics Department and Perimeter Institute.

Project Timeline, Funding, and Collaboration

Phase II planning aligns with long-term strategies articulated by the European Strategy for Particle Physics and coordinated funding proposals submitted to national bodies including CNRS, DFG, ERC, and DOE Office of Science. Major milestones synchronize with shutdown windows established by CERN Council and are informed by timelines from predecessor efforts like the High-Luminosity Large Hadron Collider. Collaboration networks include universities such as University of Cambridge, University of California, Berkeley, University of Tokyo, and laboratories such as KEK and TRIUMF, with industrial partners like Siemens and Thales supplying critical components.

Risks, Challenges, and Mitigation Strategies

Technical risks include superconducting magnet performance uncertainties encountered in programs at FNAL and CERN and cryogenic reliability lessons from ITER. Mitigation strategies involve staged prototyping with facilities such as STFC Rutherford Appleton Laboratory and qualification campaigns at CERN Test Beam Facility. Schedule and budget risks are managed via governance models used by LIGO Laboratory and SKA Organization with contingency plans coordinated through CERN Council and funding agencies like European Commission. Environmental, safety, and workforce challenges draw on protocols from ICRP recommendations and industrial best practice from partners such as Airbus.

Expected Physics Reach and Legacy

Phase II is expected to extend sensitivity to rare Higgs processes, enabling measurements that constrain models developed at Institute for Advanced Study and explored in publications from Physical Review Letters and Journal of High Energy Physics. The legacy encompasses enhanced capabilities for future collider proposals including the Future Circular Collider and Compact Linear Collider, technology transfer to industries such as semiconductor manufacturers and training of personnel affiliated with universities like ETH Zurich and Imperial College London. The program will further cement CERN’s role in global particle physics, inform award-winning research networks, and influence particle physics roadmaps coordinated by bodies like ICHEP and the European Strategy Group.

Category:Particle physics