Standardisation of 238Pu using four methods of measurement

Four independent methods of measurement were used to standardise a Pu-238 solution within the frame of an international key comparison organised by the Bureau International des Poids et Mesures, Sevres: 4pi liquid-scintillation spectrometry, alpha-particle counting at a defined solid angle, alpha spectrometry using a windowless 4pi CsI(Ti)-sandwich spectrometer and a 4pi pressurised proportional counter. The solid sources were prepared by quantitative drop deposition and a special source-drying technique. The weighted mean value of the activity concentration Of Pu-238 was found to be (360.2+/-1.0)kBqg(-1) at the reference date (I April 2001). The measurement methods, the results and the applied corrections are described and discussed. (C) 2003 Elsevier Science B.V. All rights reserved.