Determination of X- and gamma-ray emission intensities in the decay of 131 I

20th International Conference on Radionuclide Metrology and its Applications (ICRM), organized by TU Wien, 8-12 June 2015 ,Vienna, Austria.International audienceThe activity per unit mass of an iodine-131 solution was absolutely standardized by both the 4 pi beta-gamma coincidence method and the 4 pi gamma counting technique. The calibrated solution was used to prepare point sources after a preliminary deposit of AgNO3 to prevent the loss of volatile iodine. Relative and absolute photon emission intensities of 15 sgamma-rays and those of the two K X-rays of xenon were determined by gamma-ray spectrometry, with relative uncertainties of 0.8% for the three main emissions