The early construction of an 'Early DEMO' requires the accelerated construction of a neutron irradiation plant. This initial irradiation plant will have reduced specifications in terms of accumulated damage of the irradiated materials (30-40 dpa instead of 150 dpa). Thus, in the European framework it was decided to design and build a facility capable of producing the specified amount of damage as soon as possible. A discussion period was opened to determine the specifications of this so-called Early Neutron Source (ENS).
Following a proposal by the LNF, the design adopted for ENS is DONES (DEMO-Oriented Neutron Source), which basically consists of a simplification of IFMIF. Currently, the ENS is one of the EUROfusion Work Packages.
DONES will thus be similar to IFMIF but will only have one accelerator, and it will only include the irradiation modules required to test the structural materials, without a laboratory for the characterization of the irradiated samples. Based on these simplifications, both the cost and the time required for the design and construction of the facility will be significantly reduced. Also, DONES is being designed in such a way that it could eventually be upgraded in order to meet the full capabilities of IFMIF. The objective of the ENS project in the framework of EUROfusion (2015-2018) is the development of the R&D and the engineering activities required to start the construction of the facility before 2020.