Strontium-92 half-life measurement through accurate γ-ray spectrometry 05/2008; DOI: 10.1051/ndata:07440

ABSTRACT Many aspects of the nuclear fuel cycle require an accurate knowledge of the energy release from the decay of radioactive nuclides produced in a reactor, especially half-life data for short-lived radionuclides. Short-lived fission products are also important for fission rate distribution measurements performed in low power facilities, such as EOLE and MINERVE at CEA Cadarache, and their nuclear decay data need to be known with a high precision. For these reasons, the half-life of 92Sr has been measured to solve a recently observed inconsistency with the quoted value in the nuclear data libraries: T1/2 = 2.71 ± 0.01 h. In this work, a new value is proposed: T1/2 = 2.594 ± 0.005 h. A better accuracy is achieved compared to previous evaluations. It also shows a good agreement with the most recent studies: T1/2 = 2.627 ± 0.009 h.

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    ABSTRACT: 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 T1/2 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 T1/2 attained.In this work, 140La samples were obtained in the 139La(n,γ)140La 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 140La T1/2=1.6808(18) d, λ=0.47749(20)×10−5, agreeing within the uncertainities with the most accurate evaluated ones (T1/2=1.6781(3) d, λ=0.47807(9)×10−5) [2] were obtained in two series of measurements.
    Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 03/2002; DOI:10.1016/S0168-583X(01)01137-5 · 1.19 Impact Factor
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    ABSTRACT: Gamma rays emitted in the decay of 2.71 h 92Sr have been investigated with a Ge(Li) detector. Sources were prepared by separating Sr from fission products. A total of 10 γ-rays were attributed to the decay of 92Sr in a complex spectra with interferences from 91Sr and 92Y. Gamma-gamma coincidences in the decay of 92Sr were observed with a NaI(Tl)Ge(Li) setup. The decay scheme of 92Sr was constructed, involving placement of 8 of the γ-rays emitted between 92Y excited states at 241.4, 892.8, 953.3 and 1383.9 keV. The observed level structure is compared with previously reported predictions based on effective interaction calculations. The value for the half-life of 92Sr was determined to be 2.71 ± 0.01 h.
    Nuclear Physics A 11/1971; DOI:10.1016/0375-9474(71)90455-6 · 2.50 Impact Factor