Study of material response in disruption simulation experiments with variable irradiation duration

Collection of data on response of materials, and especially metals, to ITER plasma disruption-like loads remains an actual problem, in spite of a considerable volume of research. Some data on materials (Al, Cu, SS, W, graphites) responses to plasma load in disruption simulation experiments at the VIKA facility are given in this paper. Plasma heat flux specific values (w=7.5; 10; 15; 30 MJ m−2), pulse duration (τρ=0.09; 0.18; 0.27; 0.36 ms) and, in some experiments also, initial sample temperature (TS=RT-1100°C) were varied. The dynamics of material response was studied in the mode of operation with a fixed level of irradiation power (∼100 GW m−2) at pulse duration variation. It was confirmed that total mass losses (erosion depth) under plasma irradiation is determined mainly by melt layer dynamics for Be-like metal (Al). The absorbed energy coefficient for all materials decreases with both time of irradiation and the growth of plasma load. It is shown that preheating of irradiated W and graphite samples does not result in a reduction of mass losses values, but suppresses significantly cracking intensity for W.