Metallic melt generation and dynamics in ITER and DEMO

The provision of plasma-facing components (PFCs) with sufficient lifetime is one of the major technological hurdles in the development of commercial fusion reactors.

PFC integrity is mostly threatened by high power transient events with the produced metallic melt subject to external forces that excavate and displace material, causing large-scale deformation and compromising power handling.

The in-house MEMOS-U code models macroscopic melt motion in large deformation - long displacement regimes, ubiquitous in contemporary fusion devices and expected to be realized in ITER and DEMO.

It is the only code capable of evaluating both the temperature response and melt dynamics on the large spatiotemporal scales of interest.

Although MEMOS-U has been validated against experiments in current tokamaks, transient events in ITER and DEMO will bring forth presently inaccessible plasma-material interaction regimes and new physical processes affecting melt generation and dynamics.

This project aims to identify physics processes governing melt production and macroscopic motion in ITER and DEMO, to model and incorporate them in MEMOS-U, thus facilitating realistic predictions of gross melt erosion in future fusion reactors.

The major focus lies on the cooling effect due to thermionic emission, the influence of vapor shielding on melt production and the importance of electron emission processes as well as of the dynamo term in the bulk current density responsible for the dominant Lorentz force.