Analyses of the quench tank configuration for DONES liquid-lithium target system

Highlights: • Quench tank design optimization for DONES liquid-lithium target. • Comparison of two design options of the quench tank. • Thermal-hydraulic analysis of lithium flow conditions in the quench tank. • Thermal-structural analysis of quench tank structure. - Abstract: In the DONES (DEMO-Oriented Neutron Source) neutron source a single accelerator line delivers 125 mA of deuterons at 40 MeV to a flowing liquid lithium target with a free (vacuum) surface facing the deuteron beam. Neutrons with fusion-relevant spectrum are generated by a stripping reaction and used for material samples irradiation. The Quench Tank (QT) system has the function to collect the open-surface high-speed (15 m/s) lithium-flow emerging from the target assembly and deliver it to the lithium piping system under controlled conditions. Several detailed studies on specific QT design features have been performed. The following design aspects have been analysed: -Influence of the shape and orientation of the QT on the flow behaviour; -Influence of QT internal elements on the control and enhancement of the mixing of the jet with the stagnant lithium; -Transient mixing of lithium with temperature step-change due to beam on/off events; -Structural analysis of the QT. As result an optimized design of the QT with enhanced flow conditions is proposed.