As the most thermally loaded plasma-facing component in a foreseen demonstration (DEMO) reactor and beyond, the current divertor target designs can’t meet the requirement under the high neutron irradiation dose.
To solve this problem, scientists from the Institute of Nuclear Energy Safety Technology of the Hefei Institute of Physical Science (HFIPS) developed a novel liquid lithium jet-cooled finger-type divertor target concept, which is promising to provide a new option for solving the fusion DEMO reactor divertor heat removal issues.
The research group, led by Prof. YU Jie and CHEN Zhibin, analyzed the performance, and found the proposed design can withstand 20 MW/m2 heat load and proved a theoretical and empirical analysis that MHD effects on pressure drop and heat transfer is rather limited in the design.
"It's because the temperatures of the structural materials remained within the thermal rules," said ZHANG Shichao, member of the team, "and the maximum thermo-mechanical stress in the VM-W thimble is approximately 484 MPa."
They also compared this new design with other representative designs including water-cooled ITER-like target design and helium-cooled modular jet target design.
"It's striking to find that the proposed liquid Li cooled target design has better performance under 20 MW/m2 high heat flux and about 10 dpa neutron irradiation." said WANG Zhen, a nuclear engineer who joined the research.
This design has provided a new option for solving the DEMO reactor divertor heat removal issues.
This work was supported by the National Key R&D Program of China and the National Natural Science Foundation of China.
Structure design of liquid lithium jet-cooled W/ODS-CLAM finger-type divertor target (Image by WANG Zhen)
Velocity and temperature for the cooling scheme: streamline (left), velocity field (middle), temperature field (right) (Image by WANG Zhen)
Temperature filed for the W armor and structure materials (Image by WANG Zhen)
52 Sanlihe Rd., Beijing,