Simulation and Experiment Investigation of Lamination W Structure for Suppressing Surface Blistering

Tungsten (W) is a prime plasma facing materials (PFMs) in fusion reactors, facing deuterium (D) induced blistering and retention challenges. The foil gaps are the clearance between adjacent W monoblocks along the poloidal axis. They reduce D retention by acting as “gas release channels” (GRCs). By reducing monoblock thickness, we enhance GRCs effect to suppress blistering. Finite element simulations under steady-state with a flux of [[EQUATION]]D m-2s-1 modeled D transport in W monoblocks of varying thicknesses, each with a fixed-width foil gap. We accounted for the lateral escape of D into the gaps, where they recombine to form molecules(D2) released from the top. Results show that thinner monoblock (3μm) reduce near surface D retention by one order magnitude compared to 100μm W, while lowering D2 pressure in GRCs through enhanced lateral escape. To validate this approach, laminated W samples with progressively thinned W foils were fabricated and subjected to D irradiation. Experiment demonstrates three findings: (1) Blister size and density increase with fluence. (2) Thickness reduction suppresses blistering via intensified lateral escape effect (LEE), especially below 10μm and (3) Vertical cavities in W foils form GRCs suppress blistering, achieving 8.48% lower surface blister coverage than W bulk at [[EQUATION]]D m-2 fluence. This thickness-dependent suppression mechanism correlates with GRCs density optimization, where increased diffusion paths promote D recombination and release. Our combined simulation-experimental approach confirms effectiveness of laminated structure. This work presents an approach to suppress blistering in PFMs by enhancing the GRCs effect through reduced W thickness.