Non-Destructive Analysis for Hydrogen Concentrations in Materials.

摘要

The objective of the proposed research is to conduct several preliminary experiments to verify calculations made by these investigators that show it to be possible to non destructively and quantitatively determine hydrogen content in steel and possibly other host materials at the parts per million level (minimum level of from 100 to 1 ppm). The hydrogen analysis is based on the fact that 24 keV neutrons readily penetrate large thicknesses of materials composed mainly of iron with little scattering and the scattering that does occur is nearly isotropic. However, the presence of a light material (small mass number) such as hydrogen will cause significant scattering of the neutrons in a preferred forward angle, which permits these hydrogen-scattered neutrons to be distinguished from other neutrons by their particular scattering angle and energy. The number of neutrons scattered at angles and energies peculiar to hydrogen will be directly proportional to the concentration of hydrogen in the host material. Thus, the measurement of the number of hydrogen scattered neutrons will permit the quantitative, non-destructive measurement of the hydrogen concentration in test articles or samples and/or whole prototypes.