Validation of the FLUKA Monte Carlo code for predicting induced radioactivity at high-energy accelerators

Samples of different materials, consisting of major elements with masses up to the one of copper, were exposed to the stray radiation field created by a 120 GeV hadron beam in a copper target. The induced specific activities of radionuclides, as measured with gamma spectrometry, then served as benchmark of the FLUKA Monte Carlo code. A careful analysis of the experimental data as well as of the reactions leading to the various isotopes in the simulation demonstrated that FLUKA is capable of predicting individual isotopes with an uncertainty of less than 20–30% in most cases. Due to the universal nature of the high energy interaction models the results also serve as indirect validation of FLUKA predictions for target materials, reactions and isotopes not covered by this study.