The design of the DONES lithium target system

Abstract

In the framework of the EU fusion roadmap implementing activities, an accelerator-based Li(d,xn) neutron source called DONES (Demo-Oriented early NEutron Source) is being designed within the EUROfusion Work Package Early Neutron Source as an essential irradiation facility for testing candidate materials for DEMO reactor and future fusion power plants. DONES will employ a high speed liquid lithium jet struck by a 125 mA, 40 MeV deuteron beam to generate the intense neutron flux used to irradiate the material samples up to the desired level of displacement damage (˜10 dpa/fpy for iron in 0.3 l) and He production rates (˜10-13 appm He/dpa). In order to rapidly achieve a sound and stable design, a new configuration of the DONES target system based on the so-called integral concept has been proposed as reference solution in place of the former baseline design that envisaged a target assembly endowed with a replaceable back-plate, being the latter solution not yet fully qualified and thus not readily implementable. Moreover, following the outcomes of detailed dedicated analyses taking into account different aspects, the design of several components (Quench Tank, Lithium inlet pipe, Vacuum Chamber, etc.) has been changed. In this paper, a brief description of the current design of the DONES Target System is presented including all the above-mentioned aspects, showing the capability of the system to fulfil the prescribed requirements.