Tungsten Mesh Material Analysis and Assessment of Droplet Ejection Reduction*

Favorable properties of Liquid Metal Plasma Facing Components (LM-PFCs) include their ‘self-regeneration’[1], relatively benign interactions with neutrons [3], increased control of Edge Localized Modes [4], and the avoidance of thermo-mechanical cracks [2]. Particle ejection to the plasma, however, poses a key challenge, as this efflux causes MHD instabilities. The largest source of particle outflow— as seen in the HT-7 Fusion Device— arises from JXB induced droplet ejection produced by plasma current [1]. The following research seeks to quantify a wettable tungsten mesh’s ability to reduce such ejection. The mesh sample tested was produced by the ENEA-Frascati research group for Capillary Porous System LM-PFCs. Through tensile tests, single thread imaging, and JXB droplet ejection testing with PPPL’s LMX-U (Liquid Metal eXperiment Upgrade) channel, we assess the material’s possible implementation in medium speed LM concepts, such as Divertorlets [5].

[1] G.Z. Zuo et al. Fusion Eng. and Des. 89. doi:10.1016/j.fusengdes.2014.05.020.[2] Y. Hirooka et al. NF 60 doi:10.1088/1741-4326/ab4ede[3]E. Oyarzabal et al. Fusion Eng. and Des. 190 doi:10.1016/j.fusengdes.2023.113711.[4]R.E. Nygren et al. Nuclear Materials and Energy 9 doi:10.1016/j.nme.2016.08.008. [5] F.Saenz, et al. NF 62. doi: 10.1088/1741-4326/ac6682/pdf