Comparative study of ITER conform tungsten grades exposed to high heat flux and neutron irradiation damage

Tungsten is plasma-facing material (PFM) for the divertor and test blanket module to be deployed in ITER. During operation, sub-components made of tungsten will be subjected to cyclic heat exposure, plasma particles loads and bombardment by fast neutrons. The optimization of tungsten grades, in terms of mechanical properties, hopefully offering enhanced resistance against high heat flux and irradiation damage is ongoing, and recently A.L.M.T. has proposed an extra cross-rolling step for the industrial fabrication of thick tungsten plates. Here, we present the results of recent experiments aimed at characterizing the impact of high flux plasma load, thermal shock and neutron irradiation on the damage induced in newly released grades and conventional ITER specification tungsten. The assessment included the tensile mechanical properties before and after the irradiation as well as microstructural investigation of surface modification due to the high heat flux testing. The neutron irradiation and high heat flux tests were performed in a wide range of temperatures (400-1200 °C) and covered typical exposure conditions that will be met by PFM in the ITER divertor.