LNF: LIMPLASH, Liquid Metal Plasma Shields as new generation power exhaust solutions for magnetic fusion devices (2025-2028)
LNF - Nationally funded project
Title: LIMPLASH, Liquid Metal Plasma Shields as new generation power exhaust solutions for magnetic fusion devices
Reference: PID2024-161233OA-I00
Programme and date: Proyectos de Generación de Conocimiento, convocatoria 2024
Programme type (Modalidad de proyecto): Tipo A
Area/subarea (Área temática / subárea): Ciencias Físicas/Física de partículas y nuclear
Principal Investigator(s): Alfonso de Castro
Project type: Proyecto individual
Start-end dates: 01/09/2025 - 31/08/2028
Financing granted (direct costs): 40625 €
Description of the project
The development of new baseline, large scale, 24/7 availability, and carbon-free energy sources is paramount to reduce the global dependence on fossil fuels and its effects on biosphere modification, questions that are accelerating the climate change and nature degradation trends. Under such scenario, nuclear fusion is seen as hopeful option with intrinsic 24/7 availability and tremendously high energy density potential. It plans to use raw materials inexhaustible in the human time scale and not geographically concentrated, being the power generation theoretically free of long-lived radioactive wastes and inherently safe (no runaway reaction or explosions unlike fission energy). Within the magnetic fusion research, one of the key remaining issues for its development is the performance and resilience of the elements in unavoidable contact with the fusion plasma, the so-called Plasma Facing Components (PFCs) that will need to handle extreme heat fluxes (steady state 10 MW/m2 and transients of GW/m2 range in ms timescales). As the physics/technical feasibility of conventional PFC solutions (based on solid tungsten elements) and the related power exhaust scenario does not appear guaranteed or straightforward [1], active research on novel, advanced and alternative Liquid Metal (LM) PFCs has emerged mainly using Tin (Sn), lithium (Li) and their alloys (SnLi) as candidates [2]. Amid a fusion-relevant heat load irradiation scenario, LM surfaces can act as a sacrifice interface by favoring the creation of LM vapor/plasma clouds in front of it. The process is generally denominated vapor shielding [3] and offers an alternative and novel approach to the power exhaust problem. In this way, the power load fraction that utterly reaches the PFC substrate surface/structure can be decreased due to the volumetric dissipation that takes place in the LM cloud, thus allowing to enhance the total power exhaust capabilities beyond single conductive transfer that characterizes tungsten PFCs (additional vaporization, radiation and convection channels in the LM layer and vapor/plasma cloud). The experimental study and data analysis work on the fundamental characterization of LM enriched plasmoids and their associated thermal shielding regimes are the main objective of this proposal. Such plasmoids will be experimentally generated by the irradiation of prototypic LM targets with fusion relevant heat fluxes by means of both particle beam and high power laser irradiation [4]. This research on LM PFCs and their associated plasmoids attempts to explore an alternative solution that can help to handle the extreme power exhaust scenario expected in future magnetic fusion devices. The activities aim to answer scientific fundamental questions and generate basic knowledge to significantly advance in the comprehension and understanding of LM plasmoids capable of contributing to the major task of power exhaust in future fusion devices. This proposal pursues to continue a recently open research line with Sn prototypes (in which a novel LM embedded Langmuir Probe configuration has been developed [5] for LM plasmoid diagnosis), fully extend it to SnLi alloy targets and develop technological upgrades to eventually apply this research to pure lithium PFCs. The proposed works will be conducted in collaboration with world class, leading institutions in the fields of nuclear fusion and LM PFCs both in Europe (DiFFER, Netherlands) and USA (University of Illinois at Urbana-Champaign).
References
[1] J. Linke, J. Du, T. Loewenhoff et al., “Challenges for plasma-facing components in nuclear fusion”, Matter Radiat. Extrem. 4 (2019) 056201.
[2] R. E. Nygren and F. L. Tabares, “Liquid surfaces for fusion plasma facing components - A critical review. Part I: Physics and PSI”, Nucl. Mater. Energy 9 (2016) 6.
[3] G. G. van Eden T. W. Morgan et al., “Oscillatory vapour shielding of liquid metal walls in nuclear fusion devices”, Nat. Commun. 8 (2017) 192
[4] A. De Castro, et al. “Physics and technology research for liquid-metal divertor development, focused on a tin- Capillary Porous System solution, at the OLMAT high heat-flux facility”, J. Fus. Ener., 42 (2023) 45
[5] A. de Castro, M. Reji, D. Tafalla et al., “Dynamics of tin plasmoids and vapor shielding onset from a liquid metal CPS target using ITER intra-ELM energy-range H0/H+ beams”, Nucl. Fusion, 65 (2025) 056034