The development of limiters has been central to the advancement of tokamak technology, playing a critical role in plasma confinement and protecting the vacuum vessel during diverse operational phases. As tokamaks evolved toward stronger magnetic confinement and higher power densities, plasma particles incident on limiters became increasingly energetic. Early designs using high-Z materials, such as steel and molybdenum, were replaced by low-Z materials like graphite and beryllium to minimize core plasma contamination. Subsequent advancements introduced pump limiters, helical magnetic limiters, and liquid metal limiters, each addressing specific challenges in plasma-material interactions. Recent research has focused on liquid metal limiters, particularly those based on lithium and tin, owing to their regenerative plasma-facing surfaces and superior thermal management. This paper reviews the historical evolution, technological innovations, and future prospects of limiter designs in tokamaks, emphasizing their vital role in enabling high-performance magnetic confinement fusion.
Keywords: Tokamak, Limiters, Plasma-facing materials (PFMs), Plasma-material interactions (PMI), Plasma confinement, Liquid metal limiters, Lithium, Magnetic confinement fusion.
Citation: Shafiq, M. et al., (2026). Advances and Future Directions in Tokamak Limiter Technology : Transitioning from Solid to Liquid Metal System. I J T C Physics, 7(1):1-6. DOI : https://doi.org/10.47485/2767-3901.1072