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 e xperiments at the VIKA facility are given in this paper. Plasma heat f lux specific values (w = 7.5; 10; 15; 30 MJ m(-2)), pulse duration (ta u(rho) = 0.09; 0.18; 0.27; 0.36 ms) and, in some experiments also, ini tial sample temperature (T-s = RT-1100 degrees C) were varied. The dyn amics of material response was studied in the mode of operation with a fixed level of irradiation power (similar to 100 GW m(-2)) at pulse d uration variation. It was confirmed that total mass losses (erosion de pth) under plasma irradiation is determined mainly by melt layer dynam ics for Be-like metal (Al). The absorbed energy coefficient for all ma terials decreases with both time of irradiation and the growth of plas ma load. It is shown that preheating of irradiated W and graphite samp les does not result in a reduction of mass losses values, but suppress es significantly cracking intensity for W. (C) 1998 Elsevier Science S .A. All rights reserved.