Direct measurement of the half-life of 223Ra

Half-lives of La132 and La135

“…Clearly, it is important to have accurate and precise nuclear data when performing medical procedures with radionuclides, and this has led to the measurement and reevaluation of several half-lives over the past few years (see, for example, Refs. [2] and [3]). …”

Two determinations of the 223 Ra half-life

“…The uncertainties that we achieved are smaller than in most of the determinations included in the current DDEP evaluation, but larger (though only slightly so for our IC-based determination) than the uncertainties in the two recent reports by Kossert et al (2015) and Collins et al (2015). We believe our uncertainties to be realistic.…”

“…Our current 223 Ra half-life determinations appear to include the first based on γ-wc measurements and the second based on IC measurements, following the very recent report by Collins et al (2015). The uncertainties that we achieved are smaller than in most of the determinations included in the current DDEP evaluation, but larger (though only slightly so for our IC-based determination) than the uncertainties in the two recent reports by Kossert et al (2015) and Collins et al (2015).…”

“…In addition, Collins et al (2015) have very recently submitted the results of their IC-based 223 Ra half-life determination, reporting a value of 11.4358(28) d. The largest contributor to their uncertainty was due to trending in the residuals. Here again, sourceto-source variability was not included since only one 223 Ra source was measured.…”

The half-life of 227Th by direct and indirect measurements

“…The half-lives of 227 Th of 18.68(9) days (Browne, 2001) and its daughter 223 Ra of 11.4354 (17) days (Collins et al, 2015a) are of a similar magnitude, whereby the temporal dependency of the 223 Ra/ 227 Th activity is shown in Fig. 2.…”