Speaker
Description
Upgrades to the CERN Large Hadron Collider (LHC) and its experiments began on 29 June 2026 and are expected to last until 2030. During this time, the four large LHC experiments will be modified to withstand the higher collision rates and irradiation conditions of the new High-Luminosity LHC (HL-LHC). Dismantling and decommissioning of activated detector components will be followed by the installation of new detectors and electronics. A significant quantity of radioactive material will be removed from the radiation areas, and the evacuated material must undergo detailed radiological characterisation to determine the most appropriate disposal paths.
The CERN RP group typically uses the FLUKA Monte Carlo code to support radiation safety assessments and calculation of various operational radiation protection quantities. The Mesh-Enabled Fluence Weighting (MEFW) tool was developed to improve efficiency by building on FLUKA’s existing capabilities.
This paper summarises the results of a benchmark of Monte Carlo simulation predictions for the Compact Muon Solenoid (CMS) experiment. Thirty-eight samples representing three commonly used materials in accelerator and detector components were installed in various locations of the cavern and left in position for several months of beam irradiation. The samples were then analysed by means of gamma spectrometry with High Purity Germanium (HPGe) detectors. Benchmark simulations were performed with the FLUKA code and the MEFW tool.
The tool can be applied more broadly, as material composition, irradiation history, and cooling time are all defined at the post-processing stage, allowing a single simulation dataset to support multiple independent studies. As an example, the MEFW tool was used to classify LHCb detector components removed in 2018. Calculated quantities that will be presented include material activation, RADOS RTM 661/440 lnc detector response, total detectable gamma-ray signal, and the minimum object mass required for classification by RADOS measurement.
Overall, the tool supports rapid pre-assessment of clearance measurements and helps identify regions where further measurements may be required.
| Topics | T3. Code benchmarking and intercomparison |
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