Heat shock tests on beryllium samples before and after neutron irradiation

Beside carbon materials and tungsten, beryllium will play an important role as plasma facing material (PFM) in the International Thermonuclear Experim ental Reactor (ITER). It will mainly be used for the primary wall, the limi ter and the upper baffle. During off normal operation the surface of Be may be loaded by severe thermal shocks, caused by plasma disruptions with ener gies of several ten MJ/m(2) within tens of milliseconds. The influence of high heat fluxes on several un-irradiated Be grade have be en investigated before. During the operation of ITER the material will suff er irradiation with 14 MeV neutrons generated in the fusion process. In ord er to study the material degradation caused by fast neutrons, different sam ples have been neutron irradiated in the High Flux Reactor (HFR) at Petten. The thermal shock behaviour of the different beryllium grade before and af ter neutron irradiation is now compared.