Cross section of 15N-2D nuclear reactions from 3.3 to 7.0 MeV for simultaneous hydrogen and deuterium quantitation in surface layers with 15N ion beams

Abstract

The cross section for the combined 2D(15N,p)16N and 2D(15N,nγ)16O nuclear reactions of deuterium (2D) with incident 15N ions is evaluated and found to increase by two orders of magnitude between 3.3 and 7.0 MeV. Detecting the γ-rays at 6.1 and 7.1 MeV from these reactions allows quantifying the depth-integrated 2D content in materials in parallel with nanometer-resolved quantitative hydrogen (1H) depth profiling in surface layers through resonant 1H(15N,αγ)12C nuclear reaction analysis (NRA) using 15N ion beams. The information depth and sensitivity of 15N-2D NRA is estimated through energy loss simulations of the 15N projectiles in the analyzed material. Good agreement of the integral 2D quantitation through 2D(15N,p)16N and 2D(15N,nγ)16O NRA with 2D depth profiles obtained independently via 2D(3He,p)4He NRA is demonstrated at the example of 2D plasma-exposed tungsten samples. The simultaneous quantitation of 2D and depth-resolved 1H profiling with a single 15N ion beam promises application potential to investigate hydrogen-isotope exchange and diffusion processes in surface and thin buried layers.