Hydrogen uptake by high purity niobium studied by nuclear analytical methods

Niobium RF superconducting cavities form the basic component of particle accelerators. The presence of trace amounts of hydrogen in niobium is believed to have a detrimental effect on the mechanical and superconducting properties. We have used prompt gamma-ray activation analysis (PGAA) and neutron incoherent scattering to measure bulk hydrogen content in niobium, and the nuclear reaction method to study hydrogen as a function of depth. The methods were used to study native hydrogen concentrations in the niobium. and to study the effects of vacuum heating and acid treatment on the hydrogen concentration. (authors)