Journal of Applied Crystallography

Volume 39, Part 5 (October 2006)

research papers

J. Appl. Cryst. (2006). 39, 647-651 [ doi:10.1107/S0021889806025672 ]

Small-angle X-ray scattering measurements of helium-bubble formation in borosilicate glass

A. Y. Terekhov, B. J. Heuser, M. A. Okuniewski, R. S. Averback, S. Seifert and P. R. Jemian

Abstract: Small-angle X-ray scattering (SAXS) measurements have been performed to study helium-bubble formation in borosilicate glass. Helium was introduced by He⁺ implantation over an energy range of 1 to 2 MeV to give a uniform distribution over 1 µm depth. The implanted dose was varied from 9 × 10¹³ to 2.8 × 10¹⁶ ions cm^-2, corresponding to a local concentration range of 40 to 11200 atomic parts per million (a.p.p.m.) averaged over the implantation depth. The SAXS response was fit with the Percus-Yevick hard-sphere interaction potential to account for interparticle interference. The fits yield helium-bubble radii and helium-bubble volume fractions that vary from 5 to 15 Å and from 10^-3 to 10^-1, respectively, as the dose increased from 9 × 10¹³ to 2.8 × 10¹⁶ cm^-2. The SAXS data are also consistent with maximum helium solubility with respect to bubble formation between 40 and 200 a.p.p.m. in the borosilicate glass matrix.

Keywords: helium bubble; borosilicate glass; radioactive actinides.