SIMULATION OF DISRUPTIONS ON COATINGS AND BULK MATERIALS

An important issue for the next step thermonuclear fusion devices is the development of a reliable engineering solution for the first wall and in particular for the divertor. Besides severe mechanical loads, these plasma facing components (PFC) will be subjected to energetic pulses during plasma disruptions. To evaluate the performance of plasma facing materials and thus to predict the lifetime of the PFCs, simulation experiments have been performed in the JAERI electron beam irradiation stand (JEBIS). Here different candidate plasma facing materials were evaluated in short beam pulses (1.2-10 ms) with an energy deposition of 2-9 MJ m-2. The response of the individual materials to single and multiple shot beam pulses was investigated, and in these analyses special attention was given to the material erosion (melting, sublimation, particle emission). The quantification of these effects was done by weight loss measurements and by optical profilometry on the ablation craters. In addition, microstructural and morphological changes in the loaded surface were investigated.