Mobility determination of lead isotopes in glass for retrospective radon measurements rad

In retrospective radon measurements, the 22-y half life of 210Pb is used as an advantage. 210Pb is often considered to be relatively immobile in glass after alpha recoil implanted by 222Rn progenies. The diffusion of 210Pb could, however, lead to uncertain wrong retrospective radon exposure estimations if 210Pb is mobile and can escape from glass, or lost as a result of cleaning-induced surface modification. This diffusion was studied by a radiotracer technique, where 209Pb was used as a tracer in a glass matrix for which the elemental composition is known. Using the ion guide isotope separator on-line technique, the 209Pb atoms were implanted into the glass with an energy of 39 keV. The di…