Construction of proANUBIS: A proof-of-concept detector for the ANUBIS experiment

The ANUBIS experiment aims to search for long-lived particles at the Large Hadron Collider (LHC) at CERN. To assess the feasibility of the project, a prototype detector, pro ANUBIS, was designed, constructed, and prepared for installation in the UX15 ATLAS experimental cavern at the LHC. The primary physics goals of pro ANUBISare to determine the technical limitations of the detector technology and to explore the ANUBIS detector concept through in-situ measurements of muon and hadron fluxes inside the ATLAS cavern, which can be used to refine Monte Carlo simulations of such fluxes further. This report describes the design and construction of the pro ANUBISexperimental setup using Resistive Plate Chambers (RPCs), highlighting the possible future use case of the technology for ANUBIS. Details on the RPC technology, construction processes, quality control measures, and performance studies are discussed. Cosmic-ray measurements demonstrate stable detector operation and efficiencies exceeding 95% for the tested RPC chambers. Furthermore, the RPC front-end on-detector electronics and data acquisition components of pro ANUBISare presented.