A simple measurement of the Ni-63 diffusion profiles by residual activity method using a liquid scintillation counter

A simple and sensitive technique based on a solid scintillator in place of the commonly used liquid scintillation (LS) cocktail has been developed to measure the low-energy surface radioactivity with the LS counter. As a test case, the method was applied to the successful determination of the nickel-63 self-diffusion profile in commercial purity nickel by means of the Gruzin′s residual activity method. On the same sample, the additional three methods of diffusion profile determination were used to compare with the proposed new method: (i) proportional counter activity detection, (ii) serial sectioning method and (iii) an integral sample measurement in LS cocktail. In conclusion, the strong and weak points are discussed for each method.