W0442

Small-Angle X-Ray Scattering Measurements of Helium Bubbles in Borosilicate Glass. Brent J. Heuser,¹ Maria A. Okuniewski,¹ and Robert S. Averback², Univ. of Illinois, ¹Dept. of Nuclear, Plasma, and Radiological Engineering, ²Dept. of Materials Science and Engineering, Urbana, IL 61801

Small-angle x-ray scattering (SAXS) measurements have been performed to investigate He bubble formation in borosilicate glass. Helium was implanted at energies between 0.5 and 2 MeV over a dose range of 10¹⁴ to 10¹⁶ ions/cm². The local concentration associated with this dose range spans the solubility limit (approx. 100 appm) of He in glass. The measured intensity at high Q (0.02<Q<0.5 Å^-1) shows a dependence on He dose. Two effects are evident in the SAXS response. First, the scattered intensity increases with dose. Second, a peak develops at higher dose levels. This peak corresponds to interparticle interference at high particle densities. The increase in scattering intensity and development of an interference peak indicate that the He solubility limit was exceeded at higher doses, as expected.