High-precision measurement of the half-life of 147Sm

The half-life of the long-lived isotope Sm-147 Was determined by means of activity determination using liquid scintillation counting. The amount of samarium was determined by ICP-OES using a NIST reference standard. The isotopic ratio N(Sm-147)/N(Sm) of the samples was measured by means of ICP-HRMS. The half-life was found to be 1.070(9) x 10(11) y. The result is in good agreement with other evaluations and the relative standard uncertainty of 0.8% is lower than in any previous work. (C) 2009 Elsevier Ltd. All rights reserved.