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

Abstract 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.