with a large cross section and narrow resonance of 1.8 keV at a
laboratory-frame energy for 15N (6.385 MeV) resulting in a
depth resolution of around 1 nm. It is one of the most sensitive
techniques for a direct measurement of hydrogen concentration.
The method is demanding in terms of equipment,
experimental setup and procedures, but the data interpretation
is relatively straightforward. The performance concept of
NRA is based on the determination of the number of counts of
g photons that is related to the number of hydrogen species at
and in the studied specimen within the depth x. This concept
is represented schematically in Fig. 3.