Direct determination of half-life of 214Pb by gamma spectrometry and comparison with previous indirect measurements

Abstract A new value of half-life of 214 Pb was determined using 214 Pb-enriched radioactive sources made of polyurethane foam filters treated with Rn-enriched water. Measurements based on cumulative gamma rays countings yielded a value of 27.06 (7) min. This result is 0.17 min longer than the most recent value measured by indirect methods reported in the scientific literature ( Martz et al., 1991 ). The difference between these two measurements is caused by beta recoil whose effects in glass substrates had been neglected.