Influence of sub-surface damage evolution on low-energy-plasma-driven deuterium permeation through tungsten. (4th April 2018)

• Record Type: Journal Article
• Authors: Kapser, Stefan; Balden, Martin; da Silva, Tiago Fiorini; Elgeti, Stefan; Manhard, Armin; Schmid, Klaus; Schwarz-Selinger, Thomas; von Toussaint, Udo
• Is Part Of: Nuclear fusion. Volume 58:Number 5(2018:May)
• Publication Date: 2018-04-04
• Subjects: deuterium -- plasma -- permeation -- tungsten -- sub-surface damage evolution; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/aab571
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Low-energy-plasma-driven deuterium permeation through tungsten at 300 K and 450 K has been investigated. Microstructural analysis by scanning electron microscopy, assisted by focused ion beam, revealed sub-surface damage evolution only at 300 K. This damage evolution was correlated with a significant evolution of the deuterium amount retained below the plasma-exposed surface. Although both of these phenomena were observed for 300 K exposure temperature only, the deuterium permeation flux at both exposure temperatures was indistinguishable within the experimental uncertainty. The permeation flux was used to estimate the maximum ratio of solute-deuterium to tungsten atoms during deuterium-plasma exposure at both temperatures and thus in the presence and absence of damage evolution. Diffusion-trapping simulations revealed the proximity of damage evolution to the implantation surface as the reason for an only insignificant decrease of the permeation flux.