title: Half-lives of 221Fr, 217At, 213Bi, 213Po and 209Pb from the 225Ac decay series.
abstract: The half-lives of (221)Fr, (217)At, (213)Bi, (213)Po, and (209)Pb were measured by means of an ion-implanted planar Si detector for alpha and beta particles emitted from weak (225)Ac sources or from recoil sources, which were placed in a quasi-2π counting geometry. Recoil sources were prepared by collecting atoms from an open (225)Ac source onto a glass substrate. The (221)Fr and (213)Bi half-lives were determined by following the alpha particle emission rate of recoil sources as a function of time. Similarly, the (209)Pb half-life was determined from the beta particle count rate. The shorter half-lives of (217)At and (213)Po were deduced from delayed coincidence measurements on weak (225)Ac sources using digital data acquisition in list mode. The resulting values: T1/2((221)Fr)=4.806 (6) min, T1/2((217)At)=32.8 (3)ms, T1/2((213)Bi)=45.62 (6)min, T1/2((213)Po)=3.708 (8) μs, and T1/2((209)Pb)=3.232 (5)h were in agreement only with the best literature data.
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Suliman
authors.forename: S
authors.initials: S
authors.lastname: Pommé
authors.forename: M
authors.initials: M
authors.lastname: Marouli
authors.forename: R
authors.initials: R
authors.lastname: Van Ammel
authors.forename: H
authors.initials: H
authors.lastname: Stroh
authors.forename: V
authors.initials: V
authors.lastname: Jobbágy
authors.forename: J
authors.initials: J
authors.lastname: Paepen
authors.forename: A
authors.initials: A
authors.lastname: Dirican
authors.forename: F
authors.initials: F
authors.lastname: Bruchertseifer
authors.forename: C
authors.initials: C
authors.lastname: Apostolidis
authors.forename: A
authors.initials: A
authors.lastname: Morgenstern
mesh_terms: D000186:Actinium / Q000737:chemistry*; D000465:Algorithms; D006207:Half-Life; D008670:Metals / Q000032:analysis* / Q000737:chemistry*; D011829:Radiation Dosage; D011868:Radioisotopes / Q000032:analysis* / Q000737:chemistry*; D011874:Radiometry / Q000379:methods*; D019275:Radiopharmaceuticals
chemical_list: D008670:Metals; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D000186:Actinium