Demonstration of Li target facility in IFMIF/EVEDA project: Li target stability in continuous operation of entire system

Highlights: • The EVEDA Li test loop (ELTL) is a main activity in the Li target facility of the IFMIF/EVEDA project. • A long-term operation of the entire system as a demonstration of the Li target facility is presented. • The Li target was continuously operated with a cold trap for 571 h. • The Li target essentially satisfied the stability requirement of <±1 mm. - Abstract: The International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based D⁺-Li neutron source in which two 40-MeV-D⁺ beams with a total current of 250 mA are injected into a liquid Li stream flowing at 15 m/s (Li target). The EVEDA Li test loop (ELTL), which simulates the hydraulic conditions of the Li target and a part of the purification system envisaged in IFMIF, is a main activity in the Li target facility of the IFMIF/EVEDA project and has been implemented under the Broader Approach (BA) agreement since 2007. The key issues to be validated in ELTL were as follows: (1) validation of the Li target, Li target diagnostics, and cold trap (CT), and (2) validation of long-term operation. This study describes the stability of the Li target in an integrated long-term operation run of the entire system as a demonstration of the IFMIF Li target facility. The Li target was continuously operated with the CT for 571 h, and its stability was evaluated periodically using a high-precision Li target diagnostic. Therefore, the Li target essentially satisfied the stability requirement of <±1 mm throughout the continuous operation.