The role of direct energy conversion for the realization of fusion reactors

The stable supply of electric power is an important subject for the development of human civilized society, and nuclear fusion energy is one of the energy sources when the use of fossil fuel becomes difficult in future, together with nuclear fission energy and solar energy. It is important to convert controlled nuclear fusion energy to electric power with efficiency as high as possible for the improvement of its economical efficiency and the reduction of the effect to living bodies, and the primary significance of high efficiency direct electric power generation is in this point. As the object of direct electric power generation in nuclear fusion, there are the electrostatic recovery of the kinetic energy of charged particles leaking from the core plasma of fusion reactors, the method of converting plasma energy and magnetic energy to electric power through the coupling of an electromagnetic field, the in situ MHD electric power generation by liquid metal Rankine cycle using the kinetic energy of neutrons and the energy of bremsstrahlung and synchrotron radiation coming from the core plasma of fusion reactors and so on. In this paper, the role of direct electric power generation in nuclear fusion and the way of contribution that direct electric power generation makes to the realization of fusion reactors are explained, showing the concrete examples. (Kako, I.)