Thermal studies of liquid tin capillary porous system at the OLMAT high heat flux facility

• Liquid tin capillary porous system studies at OLMAT high heat flux facility. • Diagnostic window metallization due to tin deposition. • Novel iterative calibration method developed for accurate target temperature analysis. Extreme heat and particle fluxes at the divertor tiles of a fusion device present one of the most critical challenges in achieving sustainable fusion energy. Solid plasma-facing components (PFCs) typically suffer from cracking, erosion, and melting, particularly during transient events, limiting their durability and effectiveness. In contrast, liquid metal PFCs may offer several advantages over their solid counterparts, primarily through their intrinsic resistance to permanent damage and the ability to dissipate heat via multiple channels, thereby enhancing the resilience and longevity of PFCs. This work investigates the thermal behaviour of a liquid tin (Sn) capillary porous system (CPS) target exposed to a high-energy particle beam at the OLMAT high heat flux (HHF) facility. To obtain accurate temperature measurements of the target, an iterative calibration method was developed, accounting for the metallization of the diagnostic window due to the shot-by-shot deposition of eroded Sn, an effect that partially affected the measurements.