Radiation Testing of ATLAS ZDC Detector Components for the HL-LHC using a Live Irradiation Setup in the 2026 LHC pp Run

To qualify radiation-hard components for the High-Luminosity (HL) Zero Degree Calorimeters (ZDCs) at LHC, we have developed a compact, live irradiation setup (LIS). The LIS is scheduled for deployment within the Target Absorbers for Neutrals (TAN) during the 2026 LHC proton-proton run. The LIS will be integrated into the existing ATLAS ZDC readout chain and will be irradiated to a total dose of ~10 MGy.

The LIS will be used to characterize the impact of radiation on fused silica rods, LED calibration boards, and PMTs with both borosilicate and fused silica windows. Radiation testing of LED calibration boards, including SMD LEDs and inductors, informs future component selection of radiation-hard calibration boards in the HL-ZDCs. CERN FLUKA simulations provide the expected radiation dose in the TAN and motivate the placement and shielding for the LIS. PMT gain and radiation damage to fused silica rods will be monitored in real time.

Based on the studies, the HL-ZDC material selections will be finalized. Other applications of the radiation-hard materials studies presented include the forward detectors at the Electron-Ion Collider.