Study on damage behavior of the outer horizontal target in the EAST lower divertor after plasma operations

Abstract

The EAST lower divertor features a partially implemented flat-type structure, and visible damage has been observed, particularly at the outer horizontal target location after plasma operations. This study conducts a detailed analysis of the damage to the outer horizontal target. The findings reveal instances of plastic deformation, cracking, and even tungsten flake detachment at specific locations on the outer horizontal target. Furthermore, different degrees of recrystallization are identified in the tungsten plates after plasma operations, with a more pronounced effect closer to the surface of the tungsten plates. These observations offer pertinent insights for ongoing research into the microstructural enhancement design of tungsten materials and the enhancement of crack thresholds at the W/Cu interface.