Use of polarized helium-3 for the energy production

After the discovery of plentiful of minable helium-3 on the lunar surface, fusion scientists have tried to find out the methods for utilizing this attractive fuel for fusion reactors. Among various approaches, a field-reversed configuration (FRC) for confinement of fusion plasma appears the most promising candidate for a D-3He fueled fusion reactor. A conceptual design of D-3He fueled FRC reactor “ARTEMIS” (Momota et al., in: Proc. 7th Int. Conf. on Emerging Nuclear Energy Systems, Chiba, Japan, 1993) has been carried out showing that bases of engineering needed for achieving a commercial reactor are conventional and the cost of electricity from “ARTEMIS” is estimated as cheap as approximately 30 mills/(kWh). A low neutron yield allows us large freedom of reactor materials and reduces the problem of disposal of radioactive waste. In this paper, we will examine the use of polarized D-3He fuels. A favorable characteristic of polarized fuels lies on the reduction of neutron yield and the compactness of the fusion core. Because of the enhancement of reactivity of D-3He reaction by applying polarization, the neutron fraction in the total fusion power decreases to 1.3% with the same volume of “ARTEMIS” and consequently neutron wall loading is 72 kW/m2. The wall loading should be compared with 180 kW/m2 from “ARTEMIS” or 10 000 kW/m2 from a D-T fueled reactor. Consequently, this low neutron mode gives us large freedom in choosing reactor materials. The fusion reactor using polarized fuels with the same neutron yields as “ARTEMIS” decreases its size from 196 to 33 m3. This operation mode gives us the possibility of developing an economic fusion reactor.