Preparation of radiochemically pure (79)Se and highly precise determination of its half-life.
Reliable knowledge of the (79)Se half-life is crucial, e.g. for the safety assessments of final repositories for nuclear waste. However, a literature survey reveals an inconsistent picture, indicating remarkably difficult experimental conditions. This work reports a new value of 3.27(8) × 10(5) a for the half-life of (79)Se. The uncertainty is less than half of the latest published result. The sample was prepared radiochemically pure from a reprocessing solution by exploitation of reductive deposition on Cu, anion exchange chromatography and sublimation. The specific activity was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) and liquid scintillation counting (LSC). Hydride generation multicollector inductively coupled plasma mass spectrometry (HG-MC-ICP-MS) was applied for the establishment of the isotopic composition.
Jörg
Gerhard
G
Lehrstuhl für Radiochemie (RCM), Technische Universität München, Walther-Meissner-Str. 3, 85748 Garching, Germany. gerhard.joerg@radiochemie.de
Bühnemann
Rolf
R
Hollas
Simon
S
Kivel
Niko
N
Kossert
Karsten
K
Van Winckel
Stefaan
S
Gostomski
Christoph Lierse V
CL