Cross-section measurements of the $N14(α,p)O17$ and $N14(α,α)N14$ reactions between 3.5 and 6 MeV

The cross-section of the $N14(α,p0)O17$ reaction at angles of $90°$⁠, $135°$⁠, and $165°$ was measured for incident energies between 3.5 and 6.0 MeV simultaneously with the cross-section of the $N14(α,α)N14$ reaction at $165°$⁠. Interference between these two reactions at the angle of $165°$ and around 3.9 MeV was taken into account. The technique used is very powerful, thanks to the $Ta450nm/C$ target being implanted with a high dose of nitrogen. The $N14(α,p0)O17$ reaction exhibits some resonances allowing traces of nitrogen to be quantified. This reaction also offers an alternative to the $N14(d,α)C12$ and $N14(H3e,p)O16$ nuclear reactions for profiling nitrogen in the first few microns below the surface. Moreover, by using $α$-particles, Rutherford backscattering spectroscopy can be performed simultaneously with a good mass resolution to depth profile high $Z$ elements in the sample. The sensitivity of these reactions (0.1%) has been tested by measuring the nitrogen traces in a titanium oxide film deposited on silicon. Depth profiling of nitrogen in a TiN layer on a silicon substrate was also performed. In addition, we publish for the first time some cross-sections values for the $N14(α,p1)O17$ reaction at $90°$ and $165°$⁠; this measurement is a challenging task.