Hydrogen precipitation in titanium observed with neutron incoherent scattering and prompt gamma neutron activation analysis

Hydrogen mass ratios above several hundred mg/kg in metals causes embrittlement and can be determined with two neutron-based techniques: prompt gamma neutron activation analysis and neutron incoherent scattering. The latter technique has been demonstrated with cold neutrons at NIST for hydrogen mass ratios up to 300 mg/kg in 1 mm thick titanium plates. In these first demonstration experiments, scattered neutrons were detected only in the forward direction and a linear relation between the hydrogen mass ratio and the count rate in that direction was established. In this paper, it is demonstrated that more information can be obtained when the scattered neutrons are detected in two directions. Differences in chemical binding can be observed in the measured data.