HOME > Research Activities > Fusion Systems Research Division

Research Activities

Fusion Systems Research Division

In addition to reactor system design studies, this division promotes research on low activation materials and materials systems, blankets, reactor structure, plasma-facing components, and the relevant elementary processes, in order to develop mainly in-vessel components of fusion reactors. This division also enhances collaboration with universities as the core organization of an inter-university research institute in these research fields.

Currently, a study is being carried out on the microstructural evolution of materials by helium or hydrogen particle irradiation. For example, helium atoms push out lattice atoms and accumulate forming bubbles (see the figures to the right), because the solubility of helium in metals is very low. The effects of these microstructural changes on materials properties such as mechanical properties, hydrogen permeation, and retention are being investigated for the purpose of developing materials suitable for plasma-facing components.

Production, collection, and evaluation of the data on atomic, molecular, and plasma-wall interaction processes, which are necessary for fusion reactor development, are being carried out. A numerical database has been constructed and is available via a website on the NIFS homepage (http://dbshino.nifs.ac.jp).

Transmission Electron Microscopy images of helium bubbles in stainless steel induced by exposure to helium plasma discharges in the LHD (above); the schematic illustration of the bubble formation processes (below)