“…The CMSII-W coating has less porosity compared to VPS-W, and is structured with oriented, nano-sized fine grains [8]. Nevertheless, laboratory experiments have indicated that CMSII-W includes also high density of D trapping sites [18,19] Although PC-W has much lower inherent defect density compared to W coatings, D retention at depths of several m can be enhanced due to the formation of blisters [20]. The blistering is commonly observed on PC-W samples after D exposure at temperatures < 700 K in laboratory experiments, while no clear blistering was found on the AUG solid bulk PC-W tile.…”