Digital gamma activation autoradiography: A method for the study of inclusions and mineralogical texture of large size geological polished thin sections

Abstract

The nuclear analytical method of element mapping in large-sized (several dozen cm²) polished sections of geological samples was worked out. The method includes activation of the sample by bremstrahlung of an electron accelerator using a developed device for uniform sample irradiation. The next step is to obtain a series of digital autoradiograms, which is processed by the program for estimation of the decay dynamics of induced radioactivity for each pixel of the image. The data obtained are converted into a series of metaimages characterizing the distribution of induced radionuclides (measured elements) over the surface of polished thin sections. The results of mapping are in a good agreement with the data of scanning electron microscopy. The developed method is suggested for screening detection of element distribution including distinguishing of the sample zones containing PGE inclusions.