Possibility of Quasi-Steady-State Operation of Low-Temperature LHD-Type Deuterium-Deuterium (DD) Reactor Using Impurity Hole Phenomena — DD Reactor Controlled by Solid Boron Pellets —^*)

The burn control of deuterium-boron fusion reactor (DB reactor), in which the deuterium is primary fuel and the boron is additional fuel is studied numerically. Though the fusion energy which boron generates through the p-¹¹B reaction is only (1~5)% of the whole, repetitive injection of solid boron pellets realizes stable burning of a low-temperature and high-density plasma. While the operating density is controlled by the deuterium fueling, a DB reactor can be operated in the thermally unstable regime by adjusting boron pellet injection based on the temperature measurements, from a low power to a high power output mode with reduced divertor heat flux.