Application of PIGE, BS and NRA techniques to oxygen profiling in steel joints using deuteron beam

In order to study the oxygen content and to characterize the oxygen depth profile on the surface of welded steel joints in the function of the applied shielding gases, particle induced gamma-ray emission (PIGE), backscattering spectrometry (BS) and nuclear reaction analysis (NRA) methods were used. The measurements were carried out at 1.0, 1.4 and 1.8 MeV deuteron energies. From the PIGE oxygen and carbon elemental maps (1000 × 1000 μm2) taken with a beam of 2 × 2 μm2 beam size, oxygen rich regions were chosen for the depth profile analysis. The investigated depth was ∼6 μm using particle detection (BS, NRA), which was extended to ∼11 μm with the application of the differential-PIGE method, using the numerical integration of experimental cross-section data. The oxygen depth profiles show systematic discrepancy in the oxide layer thickness and composition between the two different kind of shielding gases.