Simulation of remanent dose rates and benchmark measurements at the CERN-EU high energy reference field facility

A new approach is presented for the calculation of remanent dose rates from induced radioactivity with the FLUKA Monte-Carlo code. It is based on an explicit calculation of isotope production followed by the transport of photons, positrons, and electrons from the radioactive decay to the point of interest. The approach is benchmarked with a measurement in which samples of different materials were irradiated by the stray radiation field produced by interactions of high-energy hadrons in a copper target. Remanent dose rates were measured at different cooling times with a NaI scintillator-based survey instrument. The results of the simulations are generally in good agreement with the measurements. The method is applied to the prediction of remanent dose rates around the beam cleaning insertions of the LHC. 10 Refs.