In reactor concepts using the Compact Fusion Advanced Rankine Cycle (CFAR), the mercury works as a coolant and starts to boil in the vicinity of the inlet of the tritium breeding zone, and fully vaporizes at the exit. The vaporized mercury is then superheated in the neutron superheating zone, after which it is subjected to further microwave superheating. Finally it generates electricity directly by a MHD generator. In the preliminary design, the Flibe and beryllium are charged in the tritium breeding zone. Though this design gave marginal results with excellent neutron multiplication ability of the beryllium, the cycle efficiency is still not satisfactory and other blanket concepts need to be studied. In the present design, the lithium-lead eutectic is proposed. Since the Q-value for neutron multiplication reaction of the lead is much more negative than the beryllium, less heat is produced in the tritium breeding zone. This means less mercury is required to cool this zone, and the final temperature of the mercury and the MHD efficiency could be increased. We performed parametric design studies for this concept to increase the plant efficiency under the condition that the tritium breeding ratio satisfies the planned value by utilizing the ANISN neutron transport code.
Blanket and first wall conceptual design issues of the spherical tokamak power plant