Positron annihilation spectroscopy of proton irradiated single crystal BCC iron

• Published in: Journal of nuclear materials 2006-06, Vol.351 (1), p.149-154
• Main Authors: Okuniewski, Maria A., Wells, Doug P., Selim, Farida A., Maloy, Stuart A., James, Michael R., Stubbins, James F., Deo, Chaitanya S., Srivilliputhur, Srinivasan G., Baskes, Michael I.
• Format: Article
• Language: English
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2006.02.008

Positron annihilation spectroscopy was used to analyze the open-volume defects created in single crystal, body-centered cubic iron irradiated with 1.0 MeV protons. The effects of irradiation dose and temperature were investigated. A novel technique utilizing a Bremsstrahlung beam to activate and induce positron decay in the bulk specimens, followed by Doppler broadening spectroscopy, was employed. No open-volume defects were detected in the 0.03 dpa irradiated specimens. However, the 0.3 dpa specimens exhibited an increase in the S parameter when compared to the 0.03 dpa specimens at 723 K. The 0.3 dpa specimen at 723 K indicated an increase in open-volume defects, as the radiation temperature increased compared to the 573 K, 0.3 dpa specimen. This was thought to be a consequence of the void and dislocation loop density decreasing while the void and dislocation loop diameter was increasing.