It was recalled that it was difficult to determine where H was trapped, relative to the dislocation core, and that the most promising method for doing so was small angle neutron scattering. The measured scattering intensity was governed by the spatial distribution of the square of the neutron scattering density; averaged over all orientations of the dislocation. The neutron scattering density was the sum of all of the nuclear neutron scattering lengths per unit volume. The advantage of the method lay in the fact that it was possible to observe interference between the density change of the metal, and the H or D scattering lengths. In particular, the H and D scattering lengths had opposite signs.

D.K.Ross, K.L.Stefanopoulos, K.S.Forcey, I.Iordanova: Zeitschrift für Physikalische Chemie, 1994, 183[I-II], 29-37