Kinetics of the migration and clustering of extrinsic gas in bcc metals

C. S. Deo, S. G. Srinivasan, M. I. Baskes, S. A. Maloy, M. R. James, M. Okuniewski, James F Stubbins

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We study the mechanisms by which gas atoms such as helium and hydrogen diffuse and interact with other defects in bcc metals and investigate the effect of these mechanisms on the nucleation of embryonic gas bubbles. Large quantities of helium and hydrogen are produced due to spallation and transmutation in structural materials in fusion and accelerator-driven reactors. The long time evolution of the extrinsic gas atoms and their accumulation at vacancies is studied using a kinetic Monte Carlo algorithm that is parameterized by the migration energies of the point defect entities. First-order reaction kinetics are observed when gas clusters with vacancies. If gas-gas clustering is allowed, mixed-order diffusion limited kinetics are observed. When dissociation of gas from clusters is allowed, gas-vacancy clusters survive to steady state while gas-gas clusters dissolve. We obtain cluster size distributions and reaction rate constants that can be used to quantify microstructural evolution of the irradiated metal.

Original languageEnglish (US)
Title of host publicationEffects of Radiation on Materials
Subtitle of host publication23rd International Symposium
PublisherASTM International
Number of pages13
Volume1492 STP
ISBN (Print)9780803134218
StatePublished - 2008
EventEffects of Radiation on Materials: 23rd International Symposium - San Jose, CA, United States
Duration: Jun 13 2006Jun 15 2006


OtherEffects of Radiation on Materials: 23rd International Symposium
Country/TerritoryUnited States
CitySan Jose, CA


  • First wall materials
  • Helium
  • Kinetics
  • Radiation effects
  • Structural materials
  • Theory and modeling

ASJC Scopus subject areas

  • Materials Science(all)


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