Precision half-life measurement of [formula omitted]La with Ge-detector

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2002-03, Vol.187 (3), p.419-426
• Main Authors: Adam, J., Belov, A.G., Brandt, R., Chaloun, P., Honusek, M., Kalinnikov, V.G., Krivopustov, M.I., Kulakov, B.A., Langrock, E.-J., Pronskikh, V.S., Sosnin, A.N., Stegailov, V.I., Tsoupko-Sitnikov, V.M., Wan, J.-S., Westmeier, W.
• Format: Article
• Language: English
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/S0168-583X(01)01137-5

Half-life is one of the fundamental properties of radioactive nuclei, and the precision required for its numerous applications in modern physics sometimes approaches the level of 10 −4–10 −5. Most part of the T 1/2 measurements performed up to now was made with proportional chambers, and the results were sometimes hardly reproducible within the error limits. Using Ge-detectors for that purpose brought some significant advantages but electronic unit related effects and spectra analysis procedures still remain the sources of the errors influencing the accuracy of the T 1/2 attained. In this work, 140 La samples were obtained in the 139 La( n, γ) 140 La reaction, employing a microtron as a neutron source and the half-life measurements were performed with a HPGe-detector. Influencing factors such as photopeak and background shape, electronic circuitry dead time and deadtime variations during the measurements, as well as pulse pileup are studied altogether. Values of the 140 La T 1/2=1.6808(18) d, λ=0.47749(20)×10 −5, agreeing within the uncertainities with the most accurate evaluated ones ( T 1/2=1.6781(3) d, λ=0.47807(9)×10 −5) [2] were obtained in two series of measurements.