New emanation method in Uranovy Pruzkum Liberec

Two new emanation methods are described also called exposure methods. In measurement, soil air is not sampled. Suitable foils are placed in sealed shallow bores and are evaluated following their removal. The alpha track technique uses the principle of several weeks-long exposure of a polymer foil used as a solid state track detector. The alpha card technique uses the measurement of surface alpha activity of radon daughters captured on a collection foil. The history is described of the techniques and their applications. The new emanation methods are not immediately dependent on the petrographic type of the rock environment. They can be used where deep gamma logging cannot be applied and in weak deposit prospecting. (M.D.). 4 refs., 8 figs