# First-principles calculations of momentum distributions of annihilating electron-positron pairs in defects in UO$_2$

Abstract : We performed first-principles calculations of the momentum distributions of annihilating electron-positron pairs in vacancies in uranium dioxide. Full atomic relaxation effects (due to both electronic and positronic forces) were taken into account and self-consistent two-component density functional theory schemes were used. We present one-dimensional momentum distributions (Doppler-broadened annihilation radiation line shapes) along with line-shape parameters S and W. We studied the effect of the charge state of the defect on the Doppler spectra. The effect of krypton incorporation in the vacancy was also considered and it was shown that it should be possible to observe the fission gas incorporation in defects in UO$_2$ using positron annihilation spectroscopy. We suggest that the Doppler broadening measurements can be especially useful for studying impurities and dopants in UO$_2$ and of mixed actinide oxides
Document type :
Journal articles
Domain :

Cited literature [44 references]

https://hal-cea.archives-ouvertes.fr/cea-02389430
Contributor : Amplexor Amplexor <>
Submitted on : Monday, December 2, 2019 - 3:07:35 PM
Last modification on : Tuesday, April 28, 2020 - 11:28:14 AM

### File

201600000360.pdf
Files produced by the author(s)

### Citation

Julia Wiktor, Gérald Jomard, Marc Torrent, M. Bertolus. First-principles calculations of momentum distributions of annihilating electron-positron pairs in defects in UO$_2$. Journal of Physics: Condensed Matter, IOP Publishing, 2017, 29 (3), pp.035503. ⟨10.1088/1361-648X/29/3/035503⟩. ⟨cea-02389430⟩

Record views