Measurement of the 211Pb half-life using recoil atoms from 219Rn decay

The radioactive half-life of 211Pb was measured, by α-particle counting of samples of radiochemically pure 211Pb in equilibrium with its α-emitting progeny, 211Bi and 211Po. The samples were prepared by the collection of 215Po recoil atoms from the decay of the 219Rn decay progeny produced from a 223Ra sample onto stainless steel discs. The radioactive decay of the 211Pb was measured utilising a 2π proportional counter operating on the α plateau. A half-life of 36.164 (13) min was determined, which is in agreement with currently available literature. A full uncertainty budget is presented. A recommended half-life of T1/2(211Pb)=36.161 (17) min has been evaluated from the current literature values.