EXAMINATION OF MATERIAL DAMAGE ON COMPONENTS OF FUTURE FUSION-REACTORS

Nowadays materials based on beryllium, carbon or tungsten are those mo st favored for use as wall components which will be heat loaded by the plasma in future fusion reactors. These materials are subjected to ex treme heat loads (up to 20 MWm(-2)) during normal operation. In order to carry the heat away safely, the above materials are joined to metal lic heat sinks (molybdenum or copper alloys) by an appropriate joining technique. As the components and the joints are thermally cycled by t he heat load, thermal fatigue will cause material damage. Additionally , in the case of an unsteady plasma the materials will be extremely th ermoshocked by energy densities up to 140 MJm(-2). Under these conditi ons the materials facing the plasma (Be, C, W) will be strongly eroded . At the same lime local melting, recrystallisation and cracking will cause extensive material damage.