System for visualization of radionuclide distribution in samples of mountain rock

The system for visualization of radionuclide distribution in samples of mou ntain rock is based on a combined detector: scintillating plate + image int ensifier + charge-coupled device sensor. At optimal choice of voltages, its sensitivity allows the detection of single photons with energy higher than 60 keV The specially prepared samples are located directly on a thin metal holder of a crystal. The detector has a spatial resolution of 0.3 mm. The developed technique of measuring and digital processing of raw images resul ted in two-dimensional maps of the radionuclide distributions and shadow X- ray images of samples. Superposition of the images gives coordinate positio ning in measured distributions. For separation of gamma and beta radiation of the samples, filters of various thickness were applied. Examples of imag es of rock slices with natural radionuclides and samples with technogenic p ollution are presented.