Nuclear-Reaction Analysis of Helium-3 and Tritium in Tritium-Exposed Austenitic Steels

摘要

Nuclear-reaction analysis can be used to profile sup 3 He and tritium with high sensitivity and depth resolution in tritium-exposed alloys. Helium-3 is detected via the deuteron-induced reaction sup 3 He(d,p) sup 4 He with a sensitivity better than 0.1 appM and a depth resolution of tenths of a micrometer. The sup 3 He decay product provides an essentially immobile trace of the diffusing tritium as a result of strong trapping at defects. The tritium itself can be profiled using the deuteron-induced reaction T(d,n) sup 4 He; here the sensitivity is believed better than 10 appM, and the depth resolution is comparable to that for the sup 3 He. Embrittlement-related applications of these analyses have included the determination of tritium diffusivities, solubilities ad surface permeabilities and the measurement of composition in tensile specimens.