Investigation of transient melting and splashing of metallic plasma-facing components in fusion reactors
Title: Investigation of transient melting and splashing of metallic plasma-facing components in fusion reactors
SNIC Project: SNIC 2020/13-53
Project Type: SNIC Small Compute
Principal Investigator: Ladislas Vignitchouk <ltrvi@kth.se>
Affiliation: Kungliga Tekniska högskolan
Duration: 2020-09-23 – 2021-01-01
Classification: 10303
Keywords:

Abstract

The design and operation of magnetic confinement fusion reactors, which currently represent the most promising technology to solve the world energy production problem on the long term, are restricted by the unavoidable presence of metallic dust particles produced by the interaction between the imperfectly confined plasma and the reactor chamber wall. These particles most prominently constitute a safety issue due to their becoming radioactive and chemically reactive over time. In ITER (the world’s largest experimental fusion reactor, currently under construction) and future reactors, most of the dust is expected to consist in solidified droplets splashed during transient wall surface melting events caused by plasma disruptions. The goal of this project is to explore the thermal and fluid-dynamics response of initially solid metallic surfaces exposed to fusion-relevant energy pulses using the ANSYS modelling suite. 2D simulations of a representative range of scenarios, with variations in the nature and magnitude of the energy and momentum sources involved, will allow for first estimations of the conditions required for melt layer splashing, as well as the characteristic sizes and velocities of the ejected droplets. The relatively low computational cost of simplified 2D simulations is also well suited to test numerical convergence and solver optimization, which will be crucial for future larger-scale simulations aimed at quantitative predictions of reactor wall damage and dust production in concrete, realistic scenarios.