Abstract The fusion community is looking for solutions to qualify the breeding blankets (BB) before their final testing in DEMO. Thus, ambitious and attractive proposals, like the Volumetric Neutron Source (VNS) 1, are being explored. In parallel, other possible solutions are being analyzed. Among them, IFMIF-DONES has been considered a suitable candidate since the reactions in its lithium target will produce an intense, high-energy fusion-like neutron flux, allowing the development of different fusion-related experiments. The main goal of IFMIF-DONES is the validation and qualification of structural materials to be used in DEMO, within the so-called high flux test area. In addition, the medium flux area, with a larger irradiation volume, constitutes a perfect test bench for tritium technologies validation. This paper analyzes the characteristics of the medium flux area, and presents the idea of a Test Blanket Unit (TBU), a mock-up of the BB considered representative of a certain concept (e.g. Helium Cooled Pebble Bed – HCPB or Water Cooled Lead-Lithium – WCLL). It is anticipated that the TBU will increase the TRL of this important component. Its main goal will be to contribute to the BB qualification in an irradiation environment similar to that expected in a fusion reactor, performing multi-physics experiments in an integrated testing. It is important to note that the IFMIF-DONES engineering design has been developed to maximize flexibility, and at this stage, this kind of new experiment can be proposed.
Rapisarda et al. (2025) studied this question.