226Ra measurement in Mo, Cd and Nd2O3 samples with the emanation method

Measurements of 226Ra content in materials and chemical reagents used to construct the double beta decay sources in the NEMO-3 experiment have been done with the emanation method technique. Three different radon emanation technologies were used in these studies. The first was the “traditional” method of dissolving the sample. The second was an extraction of Rn from a melted sample and finally a technique of heating fine-grained powder was used. It is shown that there is good agreement of the data received with the emanation method and low background high purity germanium detectors. The sensitivity of this method is 0.02 mBq/l of solution (for the “standard” emanation method) or 0.02 mBq/kg (for methods in which radon is extracted from a powder or melt).