Mechanical Design and Integration of a Live Irradiation Setup for the 2026 LHC pp Run

We have engineered a Live Irradiation Setup (LIS) for deployment into the Target Absorber for Neutrals (TAN) during the 2026 LHC proton-proton run. The LIS is designed to integrate with the LHC, TAN, and ATLAS Zero Degree Calorimeter readout chain. The LIS uses fused silica rods as Cherenkov radiators, PMTs for readout, and an LED-based calibration board for light-yield stability monitoring. The materials for the LIS (Cu, Al, and Steel) were chosen to minimize activation levels. The LIS is optimized for efficient installation in the high-radiation environment in the LHC tunnel. The fused silica elements and the PMTs will be irradiated to 10 MGy and 10 kGy respectively. Detailed FLUKA simulations are used to quantify the radiation doses received by various detector components and are used to predict the resulting activation levels. In addition to components for ATLAS and CMS forward detectors, the LIS will also be used to test the materials and components for the future Electron-Ion Collider.