Standardisation and decay data of Re-186

A solution of Re-186 was standardised using the 4 pi(PC)-gamma-coincidence technique. Two gamma channels were employed to provide separate detection e fficiency data arising from the two decay modes (bera and electron capture) : the resulting data were analysed using a two-dimensional extrapolation. C alibration factors for a high pressure re-entrant ionisation chamber as wel l as for the NPL secondary standard radionuclide calibrator were also deter mined. An efficiency-calibrated germanium spectrometer was used to measure the emission probabilities of the X- and gamma-rays. Crown Copyright (C) 20 00 Published by Elsevier Science Ltd. All rights reserved.