Nuclear Materials and Energy (Aug 2017)

Microstructure and defect analysis in the vicinity of blisters in polycrystalline tungsten

  • A. Manhard,
  • U. von Toussaint,
  • M. Balden,
  • S. Elgeti,
  • T. Schwarz-Selinger,
  • L. Gao,
  • S. Kapser,
  • T. Płociński,
  • J. Grzonka,
  • M. Gloc,
  • Ł. Ciupiński

Journal volume & issue
Vol. 12
pp. 714 – 719

Abstract

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Up to now, analyzing the production of dislocation-type defects in the subsurface region of plasma or ion-exposed tungsten samples has been hampered by the challenging production of suitable cross-section samples for transmission electron microscopy. We present two reliable methods based on precision electropolishing to prepare cross-sections of tungsten that allow direct imaging of dislocation-type defects by scanning as well as by transmission electron microscopy. Using these methods, we are able to demonstrate a clear enhancement of the dislocation density in the caps of blisters on tungsten exposed to H isotope plasma, i.e., of surface morphologies that are correlated to subsurface cavities. As a benchmark, we also show a cross-section of tungsten irradiated by 20 MeV W6+ ions. Keywords: Tungsten, Plasma, Blistering, Cross-section, Electropolishing, Dislocations