Surface Topographical Change of Divertor Target Plates Under Conditions Relevant to ITER ELMs

The ITER (International Thermonuclear Experimental Reactor) ELM (Large Amplitude Essential Mode) is an important problem for the terrain change on the surface of the Divertor target plate during the operation of ITER. The main function of the Divertor target plate is to filter out high-energy particles and ions in thermonuclear reactants and maintain the stable operation of subsequent devices. Due to the overload caused by ITER ELM and local extremely high heat emissions, significant terrain changes may occur on the surface of the target plate, leading to operational issues. In this paper, the surface topography of Divertor target under ITER ELM is studied by theoretical simulation and experimental research. Based on experimental measurement results and theoretical simulation predictions, the terrain changes were analyzed and explained. The research shows that ITER ELM operation will cause local high temperature and thermal stress on the surface of the target plate of the Divertor, and the surface will undergo significant deformation and distortion. In addition, the experimental results also indicate that the terrain changes on the surface of the target plate show significant differences not only in the longitudinal and transverse directions, but also in different areas of the target plate surface. Through theoretical simulation and experimental research, this paper obtained the experimental results and theoretical predictions of the terrain changes on the surface of the Divertor target under the operation of ITER ELM, which has important reference value for understanding the lubrication and preventing radiation pollution in the field of thermonuclear fusion.