The half-life of 62Cu

The half-life of the positron emitter 62Cu has been measured using 4πβ liquid scintillation (LS) spectrometry and counting in the National Institute of Standards and Technology (NIST) 4π-γ re-entrant ionization chamber (IC). A total of 12 independent LS measurements and two independent IC measurements were made, all of which spanned two to four half-lives. Weighted nonlinear fits of the data resulted in half-lives of 9.68 min ± 0.04 min and 9.673 min ± 0.026 min (uncertainties are combined standard uncertainties) for the LS and IC data, respectively (a difference of only 0.07%). The weighted mean of these two values is 9.67 min ± 0.03 min, which is shorter than the ENSDF-recommended value of 9.74 min ± 0.02 min by 0.7%. Since this radionuclide is being investigated for use in positron emission tomography (PET), this difference in the half-life has an important effect on the estimation of the amount of radioactivity administered to patients when decay corrections must be applied. (author)