Radiation damage in tungsten from cascade overlap with voids and vacancy clusters

Research output: Contribution to journalArticleScientificpeer-review

Abstract

We have performed a systematic molecular dynamics investigation of the effects of overlap of collision cascades in tungsten with pre-existing vacancy-type defects. In particular, we focus on the implications for fusion neutron irradiated tungsten in relation to comparisons with damage production under ion irradiation conditions. We find that overlap of a cascade with a vacancy-type defect decreases the number of new defects with roughly the same functional dependence as previously shown for interstitial clusters. We further find that different mechanisms govern the formation of dislocation loops, resulting in different Burgers vectors, depending on the degree of overlap between the cascade and the defect. Furthermore, we show that overlapping cascades consistently decrease the size of the pre-existing defect. We also observe void-induced cascade splitting at energies far below the subcascade splitting threshold in tungsten. The impact of these mechanisms on radiation damage accumulation and dose rate effects are discussed.
Original languageEnglish
Article number405402
JournalJournal of Physics. Condensed Matter
Volume31
Issue number40
Number of pages12
ISSN0953-8984
DOIs
Publication statusPublished - 9 Oct 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • ALLOYS
  • DEFECT PRODUCTION
  • DISLOCATION LOOPS
  • EVOLUTION
  • IN-SITU
  • MOLECULAR-DYNAMICS SIMULATION
  • NEUTRON-IRRADIATION
  • PURE TUNGSTEN
  • cascade overlap
  • dislocation loops
  • molecular dynamics
  • radiation damage
  • tungsten
  • voids
  • 114 Physical sciences

Cite this