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

Measurements of Ra-226 content in materials and chemical reagents used to c onstruct the double beta decay sources in the NEMO-3 experiment have been d one with the emanation method technique. Three different radon emanation te chnologies were used in these studies. The first was the "traditional" meth od of dissolving the sample. The second was an extraction of Rn from a melt ed 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 eman ation method and low background high purity germanium detectors. The sensit ivity of this method is 0.02 mBq/1 of solution (for the "standard" emanatio n method) or 0.02 mBq/kg (for methods in which radon is extracted from a po wder or melt). (C) 2001 Elsevier Science B.V. All rights reserved.