Neutron activation analysis of stainless steel samples and its application for monitoring thin layer wear and corrosion

الملخص EN

In this work elemental analysis for three types of stainless steel samples was performed to compare between their compositions.

First the stainless samples were analyzed using EDX and ICP spectroscopy as conventional tools for elemental analysis.

Second, the samples were subjected to detailed neutron activation analysis (NAA) using Pu-Be neutron source with applying γ-rays spectroscopic measurements for the irradiated samples.

The first sample was in the form of thin foils.

Eight radioactive isotopes were detected in the measured spectra namely 56Mn, 59Fe, 58Co, 60Co, 24Na, 187W, 99Mo and 51Cr which resulted from different neutron reaction with this sample.

The other two samples were commercial and the NAA results for one of them show that all of the elements reported in the foil sample are the same except the absence of Mo and the presence of Cr, on the other hand the third sample shows a different composition where only Mn, Fe, and Ni were identified from the measured γ- ray spectra.

Stacks of irradiated stainless steal foil and pellets were measured to obtain the activity as a function of thickness using the most intense gamma ray lines of the produced radionuclides.

The obtained linear activity-thickness relations for the measured radionuclides were fitted to determine the slope and the maximum thickness which can be measured by this technique.

The comparison between these curves showed that the most sensitive radioisotope for detecting slight changes in the thickness is 51Cr which is formed through the 50Cr(n,γ)51Cr reaction.