Conceptual design of the international fusion materials irradiation facility (IFMIF)

The International Fusion Materials Irradiation Facility (IFMIF) Conceptual Design is being carried out as an activity of the IEA Executive Committee on Fusion Materials. Initial workshops were held in 1995, in which specialists from Europe, Japan, the United States of America and the Russian Federation came together in small groups to define the concepts for three major technical systems (Accelerator, Target and Test Cell). The overall design and cost estimate is being developed in design integration meetings in which members of the four parties work together for up to a two week period. The conceptual design activity (CDA) final report was published in December 1996. The goal of the IFMIF is to provide an irradiation facility for use by fusion material scientists in the development low activation and damage resistant materials. An accelerator-based neutron source has been established through a number of international studies and workshops as an essential step for near-term materials development and testing. IFMIF would also provide calibration and validation of data from fission reactor and other accelerator-based irradiation testing. The IFMIF concept is derived from requirements from the materials community for test volumes and neutron fluences needed to obtain useful irradiation data in a reasonably short operating time. Studies indicate that a volume of about 0.5 L is required in a region producing a flux equivalent to 2 MW/m2 (0.9 x 1018 n·m-2·s-1, uncollided flux) or greater. A fraction of this volume, about 0.1 L, would be available at a flux equivalent to 5 MW/m2 for accelerated testing. The design concept consists of a deuteron accelerator producing particle energies in the range of 30 to 40 MeV. The deuterons interact with a flowing liquid lithium target (d-Li) producing high energy neutrons with a peaked flux around 14 McV. The resulting high energy neutrons will interact with a test assembly to irradiate test samples of candidate materials up to full lifetime of anticipated use in future fusion energy reactors. (author)