Activation experiment at the H4IRRAD facility: A comparison between experimental data, FLUKA and ActiWiz predictions after 15 days of cooling time

An experiment was carried out in June 2011 at the H4IRRAD facility, which allows to reproduce the radiation fields commonly encountered in the CERN Large Hadron Collider. The purpose of this study was to create a set of experimental activation data that can be used to benchmark Monte Carlo codes and now the analytical ActiWiz software package, both extensively used by CERN’s Radiation Protection Group. The choice of actual specimens that have been used for the construction of the Large Hadron Collider (LHC) and the LHC experiments has been made specifically in view of future upgrades or dismantling of CERN’s accelerators and experimental areas. Six samples of materials commonly used at CERN were irradiated by the secondary particles generated from the impact of a 280 GeV/c hadron beam on a 100 cm long copper target with the samples having been placed few centimetres below. This paper discusses first the experimental results obtained by γ-spectrometry measurements after 15 days of cooling time. Then, it discusses the FLUKA simulations performed in order to obtain the radionuclide inventories as well as the mixed particle fluence spectra in the samples. Third, it discusses the predictions by the ActiWiz software and compares them with the FLUKA results for the sake of a code comparison. Finally, the experimental and computational results are compared and discussed altogether.