Brazing for nuclear fusion reactor

In development of the nuclear fusion reactor, an important problem is development of armor materials and their structural design and manufacturing technique for the plasma faced machineries such as the first wall or the diverter plate directly facing to the plasma. Thermal load to diverter is extremely high even in the plasma faced machineries, which is estimated to be 10 to 30 MW/sq.m. As a structure resistant to such high load, a forced cooling structure is investigated to give forced cooling to the armor materials by means of metallic jointing of the armor materials with high melting point such as graphite, tungsten and others onto heat-sinking materials with high thermal conductivity such as copper and so on. This joint is required to have high reliability on considering of high thermal load, serious thermal shock and so forth of the diverter. In this paper, present statue and problems on jointing of copper heating-sinking material with carbon fiber reinforced carbon composites, one of representative proposed materials of the armor materials are described. (G.K.)