Recent developments in in-situ γ spectrometry

The objective of the present contribution is to improve standard in-situ γ spectrometry by two means: first, results of post-Chernobyl measurements of the attenuation of radiation from cesium, ruthenium, barium and iodine isotopes on lawns and meadows are presented, allowing to derive representative values of the attenuation of radiation for different time periods after deposition. Second, a method has been developed to derive the actual attenuation of the radiation from the measured spectrum by comparing the fluences of photons with different energies from single radionuclides. The application to 16 spectra demonstrates an obvious improvement of standard in-situ γ spectrometry