title: Thorium-229 quantified in historical Thorium-228 capsules.
abstract: Thorium-229 is a valuable, but scarce, radionuclide for nuclear clock applications or targeted alpha therapy. While it is mostly produced by the decay of233U,229Th can also be produced by neutron irradiation of226Ra. At SCK•CEN, capsules containing mainly228Th (by-product of226Ra irradiation) were characterized to quantify the present amounts of229Th,228Th,227Ac,226Ra with high resolution gamma spectroscopy, after a decay period of 40 years in which228Th has decayed. High purity229Th was quantified, and after recovery using radiochemical separation processes, it can be used to support ongoing research.
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium.
authors.forename: Sven
authors.initials: S
authors.lastname: Boden
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Vints
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium. Electronic address: simone.cagno@sckcen.be.
authors.forename: Simone
authors.initials: S
authors.lastname: Cagno
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium.
authors.forename: Dominic
authors.initials: D
authors.lastname: Maertens
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Van Hecke
authors.affiliation: Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium; KU Leuven, Department of Chemistry, Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cardinaels
keywords: (213)Bi; (225)Ac; (226)Ra; (227)Ac; (228)Th; (229)Th; In-situ gamma-ray spectroscopy; Nuclear clock; Targeted alpha therapy