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Published September 1992 | public
Journal Article

Nitrogen detection by means of a broad resonance at 9.3 MeV in ^(14)N(α,α)^(14)N elastic backscattering

Abstract

Because of recent interest in using high energy helium ion backscattering to measure the nitrogen content in heavy substrates, we have determined the differential cross sections for the ^(14)N(α, α)^(14)N non-Rutherford elastic scattering in the energy region 9.1–9.6 MeV at a laboratory scattering angle of 177°. A broad (Γ ∼ 200 keV) resonance around 9.3 MeV was found. The cross section was ∼ 480 mb/sr, about 190 times higher than Rutherford scattering. The resonance, allowing a depth resolution of 40–50 nm, has been used to probe an implanted nitrogen layer in stainless steel and a thick (∼ 4.5 μm) TiN coating on the surface of a high speed steel (HSS) drill bit. For quantitative analysis of nitrogen content a computer simulation method based on fitting the low energy Rutherford portion of the backscattering spectrum is proposed to extract the pseudo-Rutherford surface height of the heavy elements in substrates without knowing their non-Rutherford cross sections at such high energies.

Additional Information

© 1992 Elsevier Science Publishers B.V. Received 20 February 1992 and in revised form 13 April 1992. Supported in part by the National Science Foundation [DMR90-11230]. We would like to thank Elzbieta Kolawa and M-A. Nicolet at Caltech for preparation of the TaN and nitrogen implanted samples as well as Steve Stryker for his help in target fabrication and running the tandem accelerator.

Additional details

Created:
August 20, 2023
Modified:
October 18, 2023