Extending the energy range of materials activation modelling

Activation calculations are an essential contribution to understanding the interactions of fusion materials with neutrons. The existing state-of-the-art tools such as EASY-2003 enable calculations to be carried out with neutrons up to 20 MeV. Plans to expose fusion components to high neutron fluxes include the IFMIF materials testing facility. This accelerator-based device will produce neutrons with a high-energy tail up to about 55 MeV. In order to carry out activation calculations on materials exposed to such neutrons it is necessary to extend the energy range of the data libraries. An extension of the European Activation System (EASY) to a new version, EASY-2004, for testing has been completed. The existing reactions have been extended up to 60 MeV and new classes of reactions added using calculated cross sections. Results of preliminary calculations in an IFMIF relevant neutron field are given.