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, J. Stubbins

Research output: Contribution to journalArticlepeer-review


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)
JournalJournal of ASTM International
Issue number9
StatePublished - Oct 2007


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

ASJC Scopus subject areas

  • Environmental Engineering
  • Materials Science(all)
  • Nuclear Energy and Engineering
  • Engineering(all)
  • Public Health, Environmental and Occupational Health


Dive into the research topics of 'Kinetics of the migration and clustering of extrinsic gas in bcc metals'. Together they form a unique fingerprint.

Cite this