Effects of ELMS and disruptions on ITER divertor armour materials

This paper describes the response of plasma facing components manufactured with tungsten (macro-brush) and CFC to energy loads characteristic of Type I ELMs and disruptions in ITER, in experiments conducted (under an EU/RF collaboration) in two plasma guns (QSPA and MK-200UG) at the TRINITI institute. Targets were exposed to a series of repetitive pulses in QSPA with beat loads in a range of 1-2 MJ/m(2) lasting 0.5 ms. Moderate tungsten erosion, of less than 0.2 mu m per pulse, was found for loads of similar to 1.5 MJ/m(2) consistent with ELM erosion being determined by tungsten evaporation and not by melt layer displacement. At energy densities of similar to 1.8 MJ/m(2) a sharp growth of tungsten erosion was measured together with intense droplet ejection. MK-200UG experiments were focused on studying mainly vapor plasma production and impurity transport during ELMs. The conditions for removal of thin metal deposits from a carbon substrate were characterized. (c) 2004 Elsevier B.V. All rights reserved.