Update of the BIPM comparison BIPM.RI(II)-K1.Cd-109 of activity measurements of the radionuclide 109^{109}Cd to include the 2012 result of the LNE-LNHB (France)

International audienceSince 1978, 10 laboratories have submitted 23 samples of $^{109}$Cd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Cd-109. In 2012, the LNE-LNHB (France) participated in the comparison to update its degree of equivalence. A graphical presentation is also given

Development of interferometric techniques for nuclei size measurement in cavitation tunnel

International audienceThe knowledge of the nuclei content is essential in naval hydrodynamics for cavitation inception prediction on propellers and hydrofoils. As a matter of fact, tip vortex cavitation which is, generally, the first cavitation to occur on foils or propellers, is very sensitive to the nuclei content. Typically, the nuclei we are looking at, are tiny bubbles which sizes range from 1µm up to 100µm.Two different types of techniques are generally used: optical techniques that measure the nuclei size and Venturi techniques which measure the critical pressure of the nuclei.We present here developments of two new optical techniques: the digital in-line holography technique and the Interferometric Laser Imaging Technique based on the PIV optical arrangement. Both techniques have been implemented in the French Large Cavitation Tunnel so called GTH and comparative measurements have been done with CSM technique

Update of the BIPM comparison BIPM.RI(II)-K1.Ce-139^{139} of activity measurements of the radionuclide 139^{139}Ce to include the 2019 result of the NMISA (South Africa) and the 2022 result of the LNE-LNHB (France)

International audienceMain text Since 1976, 13 laboratories have submitted 27 samples of $^{139}$Ce to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ce-139. Recently, the NMISA (South Africa) and the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given

Final report of the new BIPM comparison BIPM.RI(II)-K1.Ra-223 of activity measurements of the radionuclide 223^{223} Ra including the 2014 result of the NPL (United Kingdom), the 2014 result of the PTB (Germany) and the 2018 result of the LNE-LNHB (France)

International audienceSince 2014, 3 laboratories have submitted 3 samples of 223 Ra to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ra-223. The NPL (United Kingdom), the PTB (Germany) and the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been calculated for the first time. The degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/ . The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA)

Results of an international comparison of activity measurements of 68 Ge

Proceedings of the 21st International Conference on Radionuclide Metrology and its Applications (ICRM), May 15-19, 2017, Buenos Aires, Argentina. Organizer: Argentinian National Atomic Energy CommissionInternational audienceAn international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11) kBq g−1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6 mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence