Programme
What is (the aim of) the Decay Data Evaluation Project?
Xavier Mougeot (LNE-LNHB)
Accurate knowledge of decay schemes and nuclear data is crucial for producing primary and secondary radioactivity standards in radionuclide metrology. This data is also widely used in various fields such as simulations, detector development, and nuclear medicine. The aim of data evaluation is to compensate for the lack of direct knowledge of certain parameters for important radionuclides, recommend new measurements, and provide new recommended data to users. The Decay Data Evaluation Project (DDEP), an international collaboration initiated by the metrology community in the 1990s, is playing a key role in this field.
DDEP evaluation of Cs-137
Sylvain Leblond (LNE-LNHB)
More than 80 years after the discovery of the first radioactive Caesium isotope, a complete re-evaluation of the 137Cs decay scheme has been performed in the scope of the Decay Data Evaluation Project, taking advantage of the most recent measurements. The presentation will focus on the methodology used to deal with inconsistent data sets and the need for new measurements to resolve the remaining mysteries surrounding this widespread isotope.
DDEP evaluation of Ho-166
Brian E. Zimmerman (NIST)
The short-lived (T1/2 = 26.801(2) h) β-emitting radionuclide Ho-166 has been investigated for a wide range of therapeutic medical applications over the past several decades. The safe and effective use of these types of radionuclides for therapy requires accurate dose assessments, which in turn require the most accurate nuclear decay data as input to the calculations. The most recent evaluations of the nuclear and atomic data or 166Ho were performed by the Decay Data Evaluation Project (DDEP) in 2004 and by the Evaluated Nuclear Structure Data File (ENSDF) in 2008. Since that time, several new measurements of the photon emission rates and decay half-life have been made, many of which were prompted by the EURAMET MetroMRT project with the express goal of improving the decay data necessary for dosimetry calculations. This talk presents the procedures used in the decay data evaluation of 166Ho that includes 5 new sets of measurements of photon emission rates and the half-life and updates the atomic and beta decay data. Comparisons with previously recommended values are provided, as are suggestions for future measurements.
