Measurement of the ²¹²Po, ²¹⁴ Po and ²¹² Pb half-life time with Timepix3

The half-life times of the relatively short-lived α α -decaying isotopes ²¹² Po 212 Po and ²¹⁴ Po 214 Po were measured with a hybrid pixel detector of Timepix3 technology. Radon daughter products were collected at the backside of a 1 mm thick silicon sensor so that subsequent decays inject the polonium isotopes of interest shallowly into the backside of the sensor. The detector’s high spatial and time resolution allow for particle identification and application of the delayed coincidence technique with low systematic uncertainty even at high rates. We find t1/2^²¹²Po = ( 295.02 ± 0.18stat. ± 0.17syst. )\,ns t 1 / 2 212 Po = ( 295.02 ± 0.18 stat . ± 0 . 17 syst . ) ns and t1/2^²¹⁴Po = ( 163.64 ± 0.038stat. ± 0.093syst. )\, s t 1 / 2 214 Po = ( 163.64 ± 0.038 stat . ± 0 . 093 syst . ) μ s . Studying the decay of the accumulated radon daughter products after removing the detector from the ²²⁰ Rn 220 Rn field, the half-life time of the β β -decay of ²¹² Pb 212 Pb was measured to be t1/2^²¹²Pb = ( 10.620 ± 0.011stat. ± 0.014syst. )\,h t 1 / 2 212 Pb = ( 10.620 ± 0 . 011 stat . ± 0 . 014 syst . ) h . The results are discussed in the context of previous works.