1 EX / P 7-10 Observation of Heat Load on the Castellated Tungsten Block by BackScattered Particles from Intentionally Misaligned Protruding Edge

During the intentionally misaligned leading edge experiment on KSTAR, an interesting feature was observed: there was clear evidence of heat load on the “aligned” castellated tungsten block in front of the misaligned ones by back-scattered particles from intentionally misaligned protruding edge. The line profiles show three different peaks corresponding to: one from the protruding edge, two others from the edge and surface of block in front of the protruding one. The deconvoluted heat flux profile and corresponding intensity ratio of each peak show that up to 46 % of IR intensity was originated from the block in front of the protruding one: around 44 % from the edge and 2 % from the surface. The peak intensity of back scattered profile depends strongly on the strike point location, which indicates the contribution of energetic ions during ELM.