Depth profiling of hydrogen under an atmospheric pressure

Nuclear reaction analysis of hydrogen with a use of the 1H(15N,αγ)12C reaction was performed under a atmospheric condition. A 100 nm-thick silicon nitride membrane coated with gold of 10 nm was used for the extraction of the 15N beam into the sample chamber filled with gas molecules. Hydrogen contained in a Y film with a thickness of 80 nm was detected in N2 of 105 Pa. This nuclear reaction analysis (NRA) setup was also applied to H2 gas, and the yield curve revealed a plateau feature. The plateau level was, furthermore, found to be constant independent of the H2 pressure. We show that this plateau intensity can be used to obtain the detection efficiency of a NRA setup.