Modelling deuterium release from tungsten after high flux high temperature deuterium plasma exposure

Research output: Contribution to journalArticle

Authors

Institutes & Expert groups

  • UGent - Universiteit Gent
  • PbPU - Peter the Great St.Petersburg Polytechnic University - Russia
  • FZJ - Forschungszentrum Jülich GmbH

Documents & links

Abstract

Tungsten is a primary candidate for plasma facing materials for future fusion devices. An important safety concern in the design of plasma facing components is the retention of hydrogen isotopes. Available experimental data is vast and scattered, and a consistent physical model of retention of hydrogen isotopes in tungsten is still missing. In this work we propose a model of non-equilibrium hydrogen isotopes trapping under fusion relevant plasma exposure conditions. The model is coupled to a diffusion-trapping simulation tool and is used to interpret recent experiments involving high plasma flux exposures. From the computational analysis performed, it is concluded that high flux high temperature exposures (T=1000 K, flux=1024 D/m2/s and fluence of 1026 D/m2) result in generation of sub-surface damage and bulk diffusion, so that the retention is driven by both sub-surface plasma-induced defects (bubbles) and trapping at natural defects. On the basis of the non-equilibrium trapping model we have estimated the amount of H stored in the sub-surface region to be ~10-5 at-1, while the bulk retention is about 4×10-7 at-1, calculated by assuming the sub-surface layer thickness of about 10 μm and adjusting the trap concentration to comply with the experimental result for the integral retention.

Details

Original languageEnglish
Pages (from-to)181-189
Number of pages8
JournalJournal of Nuclear Materials
Volume481
DOIs
Publication statusPublished - 1 Dec 2016

Keywords

  • Modeling, Deuterium release, tungsten, high , Temperature, flux, plasma , exposure

ID: 2179052