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  • BIPM-5

    • X-ray and Gamma-ray Decay Data
    Standards for Detector Calibration and Other Applications

    Recommended Decay Data, High-Energy Gamma-Ray Standards and Angular Correlation Coefficients

    Closing date of evaluations and database assembly: December 2005

    The database contains recommended half-lives and X-ray and γ-ray emission probabilities for a set of radionuclides identified as appropriate for the efficiency calibration of X/γ-ray detectors. This database also extends to high-energy γ-ray emissions from a series of nuclear reactions, and a set of angular correlation coefficients. Links are provided to the tables and files of the recommended data.

    The decay data files include the following:

    - recommended half-lives;
    - recommended X-ray energies and emission probabilities;
    - recommended γ-ray energies and emission probabilities (with the emphasis of the evaluation efforts placed on the emission probabilities);
    - recommended γ-ray energies and emission probabilities for high-energy γ rays;
    - recommended angular correlation coefficients for two successive cascading γ rays (specified for eleven radionuclides).

    Detailed descriptions of the evaluation work and the recommended decay data can be found in the final technical report (Volume 1, Volume 2, Volume 1+2 ). A short outlineof the work programmes is given on the Coordinated Research Project page, along with a list of evaluators involved in these studies.

    A major aim has been to re-define and produce data files that will be internationally accepted so as to improve the uniformity and consistency of subsequent measurements of photon emission probabilities. The various decay data evaluations were undertaken over a rather lengthy period of time from September 1996 to December 2005, depending on the radionuclide being assessed. These decay data should be willingly accepted by γ-ray spectroscopists, and adopted in their work. High-quality decay data are essential in the efficiency calibration of X- and γ-ray detectors that are used to quantify the radionuclidic content of materials/samples through the determination of the intensities of the resulting X-ray and γ-ray emissions. Recommended values of the half-lives and photon emission probabilities of a selected set of radionuclides have been evaluated and assembled as easily accessible data files. The decay data can also be applied in other specific fields of nuclear science (e.g. dosimetry, nuclear medicine, environmental monitoring, waste management and safeguards).

    Efforts to improve many of the recommended decay data to be found on this web site continue through the Decay Data Evaluation Project (DDEP) under the coordination of Laboratoire National Henri Becquerel ( LNHB ), France, and as adopted by Bureau International des Poids et Mesures (BIPM). These studies are reported in some detail in refs. [1, 2, 3, 4] ( BIPM-5 ).

    References

    [1] BÉ, M.-M., CHISTÉ, V., DULIEU, C., BROWNE, E., CHECHEV, V., KUZMENKO, N., HELMER, R., NICHOLS, A., SCHÖNFELD, E., DERSCH, R., Table of Radionuclides, Vol. 1 - A = 1 to 150, Monographie BIPM-5 (2004) Bureau International des Poids et Mesures.

    [2] BÉ, M.-M., CHISTÉ, V., DULIEU, C., BROWNE, E., CHECHEV, V., KUZMENKO, N., HELMER, R., NICHOLS, A., SCHÖNFELD, E., DERSCH, R., Table of Radionuclides, Vol. 2 - A = 151 to 242, Monographie BIPM-5 (2004) Bureau International des Poids et Mesures.

    [3] BÉ, M.-M., CHISTÉ, V., DULIEU, C., BROWNE, E., BAGLIN, C., CHECHEV, V., KUZMENKO, N., HELMER, R., KONDEV, F., MACMAHON, D., LEE, K.B., Table of Radionuclides, Vol. 3 - A = 3 to 244, Monographie BIPM-5 (2006) Bureau International des Poids et Mesures.

    [4] BÉ, M.-M., CHISTÉ, V., DULIEU, C., BROWNE, E., CHECHEV, V., KUZMENKO, N., KONDEV, F., LUCA, A., GALÁN, M., PEARCE, A., HUANG, X., Table of Radionuclides, Vol. 4 - A = 133 to 252, Monographie BIPM-5 (2008) Bureau International des Poids et Mesures.