Determination of 239Pu/240Pu isotopic ratio by high-resolution alpha-particle spectrometry using the ADAM program

R Pöllänen; T Siiskonen; S Ihantola; H Toivonen; A Pelikan; K Inn; J La Rosa; B J Bene

doi:10.1016/j.apradiso.2011.12.026

Determination of 239Pu/240Pu isotopic ratio by high-resolution alpha-particle spectrometry using the ADAM program

Appl Radiat Isot. 2012 Apr;70(4):733-9. doi: 10.1016/j.apradiso.2011.12.026. Epub 2011 Dec 22.

Authors

R Pöllänen¹, T Siiskonen, S Ihantola, H Toivonen, A Pelikan, K Inn, J La Rosa, B J Bene

Affiliation

¹ STUK-Radiation and Nuclear Safety Authority, PO Box 14, FI-00881 Helsinki, Finland. roy.pollanen@stuk.fi

PMID: 22227537
DOI: 10.1016/j.apradiso.2011.12.026

Abstract

A novel analysis program to unfold alpha-particle energy spectra was introduced, demonstrated and validated using radiochemically processed test sources, which contained different amounts of (239)Pu and (240)Pu. A high-resolution alpha spectrometer was used for data acquisition. The software known as ADAM unfolds the spectra using nuclide-specific decay data as a constraint. The peaks can have different shapes and the software can also cope with the coincidences between alpha particles and electrons/photons. In the present paper, the (239)Pu/(240)Pu activity ratios from alpha spectrometry agreed, within the stated uncertainties, with the reference values. Number of counts in the (239,240)Pu peak group must be larger than 100 to obtain reliable values when using semiconductor detector of energy resolution FWHM=10.6 keV.