A Long-Baseline Atom Interferometer at CERN LHC Point 4: Implementation Study

TL;DR

This study details the technical plan for installing a long-baseline atom interferometer at CERN LHC Point 4 during LS3, ensuring compatibility with LHC operations and addressing engineering, safety, and logistical challenges.

Contribution

It provides a comprehensive implementation plan and feasibility assessment for integrating a long-baseline atom interferometer at CERN without disrupting existing LHC activities.

Findings

No fundamental obstacles to implementation

Installation can be completed within 1.5 years after approval

Seamless operation of the interferometer with LHC is feasible

Abstract

Building on the feasibility study in CERN-PBC Report-2018-002 (Arduini et al. 2018), this report supported by the Physics Beyond Colliders (PBC) Study Group describes the technical implementation of modifications to the PX46 shaft at LHC Point 4 during LS3 (June 2026 - June 2030) that would enable it to accommodate the installation and operation of a vertical long-baseline Atom Interferometer during Run 4 without affecting LHC operations. We specify in detail the necessary civil-engineering work, installation of bespoke radiation shielding, deployment of access-control systems and safety alarms, and design of a mobile elevator platform. Our comprehensive technical assessment identifies no fundamental obstacles or showstoppers to implementation. Refined cost estimates and a critical-path schedule confirm that, from formal approval, all interventions can be completed within a 1.5-year window. These preparations would ensure seamless, concurrent operation of the Atom Interferometer experiment and the HL-LHC, with all technical challenges successfully addressed through established engineering solutions.