INSITU NRA STUDIES OF HYDROGEN INGRESS INTO ZR-2.5 WT-PERCENT NB AT THE LIQUID SOLID INTERFACE

Deuterium ingress into thin (3-5-mu-m) foils of Zr-2.5 wt.% Nb has been studied with the D(He-3,p)He-4 nuclear reaction. The foils were mounted in a compact cell in a vacuum chamber and a He-3 beam bombarded the foil and liquid in the cell. We introduced approximately 30 at.% of D into the foil by removing the native oxide layer with a solution of 0.1 wt.% NH4HF2 in D2O and then cathodically charging the foil using a 0.1M H2SO4 in D2O solution. We anodized these foils, as well as unetched ones, using 0.1M H2SO4 in D2O solution, and then measured the deuterium content in situ as well as in separate experiments with the anodized surface turned toward the beam.