Speaker
Description
Liquid metals plasma facing component composed either of Lithium, Tin or Gallium are considered for heat exhaust in future fusion power plants. Different concepts from liquid metal in capillary structures or free flowing liquid metal layers have already been applied and considered for different devices [1,2] and are now investigated for future machines such as Renaissance Fusion stellarator concept where a liquid layer of Lithium / Lithium Hydride (Li/LiH) is used as the main plasma facing component. In addition to challenges regarding MHD stability of such layers where electric currents can flow, it is mandatory to study the impact of the contamination of the plasma by eroded and evaporated Lithium.
Following existing modelling with the SOLEDGE2D code [3], a numerical model has been designed to estimate Lithium sources from the wall when exposed to plasma fluxes. This model implements a thermal part to compute Lithium film temperature depending on plasma heat flux deposition, neutron energy absorption and liquid film flow velocity. Given Lithium temperature, evaporated and eroded fluxes are computed and taken into account as sources for edge plasma transport simulations with the SOLEDGE3X code. The impact of the vapor shielding on the heat exhaust is self-consistently taken into account by an iterative procedure coupling SOLEDGE3X transport simulations and Li/LiH wall modelling. This framework is similar to the one recently implemented by the UEDGE/Wall-Li coupling [4] and applied to NSTX. Finally, we attempt to estimate the fuel retention within the liquid layer and discuss the consequences of a low recycling coefficient on Liquid Lithium wall - as observed at LTX [5] - on edge plasma characteristics.
Acknowledgements:
This project was funded within the France 2030 programme (contract DOS0223063/00)
[1] M.A. Jaworski et al., Nucl. Fus. 53 (2013)
[2] R.J. Goldston et al., Phys. Scr. T167 (2016)
[3] L. Balbinot PhD thesis (2022) - https://hdl.handle.net/11577/3480852 (Universita degli Studi di Padova, Gent Universiteit)
[4] M.S. Islam et al., Phys. Plasmas 32 (2025)
[5] D.P. Boyle et al., Phys. Rev. Letters 119 (2017)