Surface Wear Studies in Some Materials Using α-induced Reactions

Abstract

The radio-activity produced during the irradiation of 63,65 Cu, 59 Co, 93 Nb and 121,123 Sb targets with α-particles have been measured using activation technique. The yields of radioactive isotopic products 66,67,68 Ga, 61 Cu, 96g,m Tc and 123,124,126 I have been determined in the energy range ≈ 10-40 MeV using stacked foil technique. Radioactive counting of samples was performed with a high-resolution gamma-spectrometer. As light ion beams produce an extremely narrow layer of activities in the surface of a material, these reactions may be useful for thin layer activation study. 1. IntR oDUctIon The thin layer activation (TLA) technique has become a widely used sensitive tool to study the surface wear of micron order in metallic surfaces in various engineering components. It is known that reliability of industrial equipments, transport systems, power plants both nuclear as well as conventional etc., is considerable influenced by the process of wear, corrosion and erosion. As such, the development of effective methods for the detection, measurements and monitoring of these processes are quite important. This is an important aspects in the sense that dangerous accidents during operation of industrial installation, and production losses may be avoided due to machine break-down. The charged particle activation for measurement and monitoring of corrosion and wear is important particularly when the parts of the surface are not really accessible. In TLA method, radioactivities in thin layers of the metallic foils are induced by bombarding them with light charged particles like protons, deuterons and α-particles. The incident charged particles may produce radio-active residues in the target material through nuclear reactions. The yield of the radio-active residues as a function of the depth gives the profile of surface wear. The yield of a particular radio-isotope may be determined from the measured cross-sections for that reaction responsible for the formation of the residue. The cross-sections for the production of