Radiation-Enhanced Saline Leaching of Silicate Glasses

Abstract

A short ion bombardment greatly increases the hot saline etching or leaching of silicate glasses. The effect was observed for xenon, argon, neon, helium, and deuterium ion bombardment. From the relative values of the effect produced by the several ions, it was demonstrated that the effect is associated with the hot secondaries. The hot saline can cause the complete removal of material, thus producing a depression of an irradiated area, which was measured interferometrically, or it may cause a leaching of the cationic content of the glass and leave a silaceous residual film, which was studied by obtaining its spectral reflectivity. Other glasses may behave in an intermediate manner leading to some depression and some film residue. The glasses studied were soda-lime glass, light barium crown (28% BaO), and two facsimile radioactive waste storage glasses. The first two showed the enhanced etching, the first waste storage glass a tenacious film, and the second waste storage glass showed the intermediate behavior, some etching, and some film residue. The enhancement of the etching rate of the light barium crown glass was calculated as some fivefold, for the soda-lime glass about elevenfold. Enhancement of the leaching rate of the first waste storage glass was for helium ion bombardment and over for xenon or neon ion bombardment.