Disintegration rate measurement of A 152Eu solution

The procedure followed by the Laboratório de Metrologia Nuclear at the IPEN-CNEN/SP, in São Paulo, for the standardization of 152Eu is described. The disintegration rate of 152Eu has been measured using the 4πβ−γ coincidence technique, using a 4π proportional counter, filled with P-10 gas and operated at 0.1 MPa, coupled to one HPGe detector for the γ-ray emission. Two discrimination windows were set in the γ-channel, one related to the beta branch (344 keV) and the other related to the electron capture events (1408.03 keV), in order to determine the counting efficiencies for β, X-ray and Auger electron events in the proportional counter. The activity of solution was determined by a biparametric extrapolation curve obtained for the two selected γ-windows.