Study of the double beta decays of 96Ru and 104Ru.

In this work we present new improved experimental limits for the partial half-lives of the double beta processes of (96)Ru and (104)Ru, obtained by means of a γ-ray spectrometry measurement. A disc of metallic Ru of natural isotopic abundance was sandwiched between two HPGe-detectors in the 225 m deep underground laboratory HADES. After 108 days of measurement, the lower bounds for the partial half-lives were up to 6.

Natural radioactivity in winter wheat from organic and conventional agricultural systems.

The distribution of natural radionuclides was studied in winter wheat plants collected from three sites in Belgium during 2004-2007. Activity concentrations of (40)K, (226)Ra, (228)Ra and (228)Th in organically and conventionally grown wheat, and in the corresponding soil samples, were determined using ultra low-level gamma-ray spectrometry. The observed soil-to-wheat concentration ratios were calculated for the different parts of the wheat plant (root, stem and grain) in the two agricultural systems (organic and conventional).