The influence of impurities on the molten depths in simulated plasma disruptions
Plasma-facing components in tokamak-type fusion reactors are subjected to intense heat loads during plasma disruptions. The influence of high heat fluxes on the depths of heat-affected zones on Type 316 stainless steel with different sulfur impurities was studied for a range of energy densities and disruption times. It was demonstrated in small beam simulation experiments that under certain conditions, impurities create convective flows through their effect on surface tension, hence exercising a determining influence on the flow intensities and the resulting depth of molten layers. When a CO(2) laser is used as a heat source, the role of impurities diminishes, due to high temperatures on the surface of the specimens, and all types of stainless steel behave like pure material. However, by using an alternative heat source that produces lower surface temperatures, such as tungsten inert gas, the stainless steel containing high sulfur produces much higher melting zone thicknesses compared with the low sulfur steels. Comparisons between experimental results and existing theoretical predictions reveal significant differences in the depths of the melt layers.
Bibliographic Reference: Article: Fusion Technology, Vol. 26 (1994) pp. 7-16
Record Number: 199510053 / Last updated on: 1995-01-10
Original language: en
Available languages: en