Physical and Metallurgical Phenomena During Simulations of Plasma Disruptions

Abstract The metallographic analysis executed on austenitic stainless steel specimens subjected to simulated plasma disruptions allows us to present a complete picture of the most important phenomena. 1. (i) The experiments show that for the calculation of melt layer and evaporation it is necessary to take considerable convection in the melt layer into account. 2. (ii) The rapid solidification of the melt layer leads to a change in the crystalline structure and to the formation of cracks. 3. (iii) Alloying elements with a high vapour pressure evaporate preferentially. 4. (iv) The stresses generated during cooling induce in some cases phase changes. 5. (v) During neutron irradiation helium is formed in all first wall materials by (n, α) processes. This helium forms bubbles under disruptions.