Lifetimes of ~(214)Po and ~(212)Po measured with Counting Test Facility at Gran Sasso National Laboratory

摘要

The decays of ~(214)Po into ~(210)Pb and of ~(212)Po into ~(208)Pb tagged by the previous decays from ~(214)Bi and ~(212)Bi have been studied inserting quartz vials inside the Counting Test Facility (CTF) at the underground laboratory in Gran Sasso (LNGS). We find that the mean lifetime of ~(214)Po is (236.00 ± 0.42(stat) ± 0.15(syst)) μs and that of ~(212)Po is (425.1 ± 0.9(stat) ± 1.2(syst)) ns. Our results are compatible with previous measurements, have a much better signal to background ratio, and reduce the overall uncertainties.