The development of structural materials for fusion reactors

Structural materials for first-wall and breeding-blanket components will be exposed to 14 MeV neutrons, plasma particles and electromagnetic radiation . In magnetically confined systems, the operation mode will be quasi-contin uous. Typical operation conditions for next-step devices and demonstration plants will be described. The selection of suitable structural materials is based on conventional properties, their resistance to radiation-induced da mage phenomena and the additional requirement of low neutron-induced radioa ctivity. Presently, low-activating ferritic-martensitic steels, vanadium al loys and ceramic composites are investigated as promising candidates. In th e paper the present status of knowledge is reviewed and the critical issues for the different alternatives are elaborated. The necessity of an appropr iate neutron source for the testing and qualification of the materials unde r fusion-specific conditions is also stressed.