Precise and accurate determination of alpha decay half-life of 244Pu by relative activity method using thermal ionization mass spectrometry and alpha spectrometry

Alpha decay half-life of 44Pu has been re-determined using thermal ionization mass spectrometry for atom ratios measurements and alpha spectrometry for alpha activity ratios measurements. Two different samples of enriched 244Pu were used and the 244Pu half-life was determined using 240Pu and 242Pu isotopes as reference nuclides in the relative activity method. A value of (8.12±0.03) x 107yr is recommended for the half-life of 244Pu based on the present data. This value is of high precision and accuracy compared to the two data reported in 1966 and 1969 with significantly-larger uncertainties. (orig.)