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1. Precise activity measurements of medical radionuclides using an ionization chamber: a case study with Terbium-161

Author

Frédéric Juget, Zeynep Talip, Youcef Nedjadi, M. Teresa Durán, Pascal V. Grundler, Jan Rijn Zeevaart, Nicholas P. van der Meulen, and Claude Bailat

Subjects
161Tb, Système International de Référence, Low-energy gamma, Activity measurement, Radionuclide dose calibrator, Medical physics. Medical radiology. Nuclear medicine, R895-920
Abstract

Abstract Background 161Tb draws an increasing interest in nuclear medicine for therapeutic applications. More than 99% of the emitted gamma and X-rays of 161Tb have an energy below 100 keV. Consequently, precise activity measurement of 161Tb becomes inaccurate with radionuclide dose calibrators when using inappropriate containers or calibration factors to account for the attenuation of this low energy radiation. To evaluate the ionization chamber response, the sample activity must be well known. This can be performed using standards traceable to the Système International de Référence, which is briefly described as well as the method to standardize the radionuclides. Methods In this study, the response of an ionization chamber using different container types and volumes was assessed using 161Tb. The containers were filled with a standardized activity solution of 161Tb and measured with a dedicated ionization chamber, providing an accurate response. The results were compared with standardized solutions of high-energy gamma-emitting radionuclides such as 137Cs, 60Co, 133Ba and 57Co. Results For the glass vial type with an irregular glass thickness, the 161Tb measurements gave a deviation of 4.5% between two vials of the same type. The other glass vial types have a much more regular thickness and no discrepancy was observed in the response of the ionization chamber for these type of vials. Measurements with a plastic Eppendorf tube showed stable response, with greater sensitivity than the glass vials. Conclusion Ionization chamber measurements for low-energy gamma emitters (

Published
2022
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2. Activity Measurement of 44Sc and Calibration of Activity Measurement Instruments on Production Sites and Clinics

Author

Frederic Juget, Teresa Durán, Youcef Nedjadi, Zeynep Talip, Pascal V. Grundler, Chiara Favaretto, Pierluigi Casolaro, Gaia Dellepiane, Saverio Braccini, Claude Bailat, and Nicholas P. van der Meulen

Subjects
Sc-44 production, medical cyclotron, positron emission tomography, precise activity measurement, dose calibrator, γ-ray spectrometry, Organic chemistry, QD241-441
Abstract

44Sc is a promising radionuclide for positron emission tomography (PET) in nuclear medicine. As a part of the implementation of a production site for 44Sc, precise knowledge of the activity of the product is necessary. At the Paul Scherrer Institute (PSI) and the University of Bern (UniBE), 44Sc is produced by enriched 44CaO-target irradiation with a cyclotron. The two sites use different techniques for activity measurement, namely a dose calibrator at the PSI and a gamma-ray spectrometry system at UniBE and PSI. In this work, the 44Sc was produced at the PSI, and samples of the product were prepared in dedicated containers for onsite measurements at PSI, UniBE, and the Institute of Radiation Physics (IRA) in Lausanne for precise activity measurement using primary techniques and for the calibration of the reference ionization chambers. An accuracy of 1% was obtained for the activity measurement, allowing for a precise calibration of the dose calibrator and gamma-ray spectrometry of the two production sites. Each production site now has the capability of measuring 44Sc activity with an accuracy of 2%.

Published
2023
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3. Production of Mass-Separated Erbium-169 Towards the First Preclinical in vitro Investigations

Author

Zeynep Talip, Francesca Borgna, Cristina Müller, Jiri Ulrich, Charlotte Duchemin, Joao P. Ramos, Thierry Stora, Ulli Köster, Youcef Nedjadi, Vadim Gadelshin, Valentin N. Fedosseev, Frederic Juget, Claude Bailat, Adelheid Fankhauser, Shane G. Wilkins, Laura Lambert, Bruce Marsh, Dmitry Fedorov, Eric Chevallay, Pascal Fernier, Roger Schibli, and Nicholas P. van der Meulen

Subjects
Er-169, electromagnetic isotope separation, lanthanide-separation, activity standardization, in vitro studies, laser resonance ionization, Medicine (General), R5-920
Abstract

The β−-particle-emitting erbium-169 is a potential radionuclide toward therapy of metastasized cancer diseases. It can be produced in nuclear research reactors, irradiating isotopically-enriched 168Er2O3. This path, however, is not suitable for receptor-targeted radionuclide therapy, where high specific molar activities are required. In this study, an electromagnetic isotope separation technique was applied after neutron irradiation to boost the specific activity by separating 169Er from 168Er targets. The separation efficiency increased up to 0.5% using resonant laser ionization. A subsequent chemical purification process was developed as well as activity standardization of the radionuclidically pure 169Er. The quality of the 169Er product permitted radiolabeling and pre-clinical studies. A preliminary in vitro experiment was accomplished, using a 169Er-PSMA-617, to show the potential of 169Er to reduce tumor cell viability.

Published
2021
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4. Half-life measurement of 44Sc and 44mSc

Author

M. Teresa Durán, Frédéric Juget, Youcef Nedjadi, Claude Bailat, Pascal V. Grundler, Zeynep Talip, Nicholas P. van der Meulen, Pierluigi Casolaro, Gaia Dellepiane, and Saverio Braccini

Subjects
Radiation, 530 Physics
Abstract

The half-lives of 44Sc and 44mSc were measured by following their decay rate using several measurement systems: two ionization chambers and three γ-spectrometry detectors with digital and/or analogue electronics. For 44Sc, the result was the combination of seven half-life values giving a result of 4.042(7) h, which agrees with the last reported value of 4.042(3) h and confirms the near to 2% deviation from the recommended half-life of 3.97(4) h. Scandium-44 is present as an impurity in the production of 44Sc by cyclotron proton irradiation. Its half-life was determined by measurements performed a few days after End of Bomardment (EoB), so that the 44Sc decayed down to a negligible level. Seven measurements were combined to obtain an average of 58.7(3) h, which is in agreement with the recommended value of 58.6(1) h.

Published
2022

5. Ytterbium-175 half-life determination

Author

Claude Bailat, Thierry Stora, Youcef Nedjadi, François Bochud, Zeynep Talip, M. Teresa Durán, Ulli Köster, Frédéric Juget, Charlotte Duchemin, and Nicholas P. van der Meulen

Subjects
Physics, Radionuclide, Spectrum analyzer, Radiation, Analogue electronics, Nuclear engineering, Detector, Nuclear data, 010403 inorganic & nuclear chemistry, 01 natural sciences, 0104 chemical sciences, Metrology, 010309 optics, Neutron capture, 0103 physical sciences, Ionization chamber
Abstract

$^{175}$Yb is a radionuclide that can be generated by neutron capture on $^{174}$Yb and whose decay properties make it useful for developing therapeutic radiopharmaceuticals. As it happens with many of the emerging radionuclides for medical uses in recent years, its nuclear data were determined decades ago and are not thoroughly documented nor accurate enough for metrological purposes. The last documented reference for the $^{175}$Yb half-life value is 4.185(1) days and dates back to 1989, so a redetermination of the value was considered appropriate before standardization at the Institute of Radiation Physics (IRA, Lausanne, Switzerland) primary measurements laboratory. Three independent measurement methods were used to this purpose: reference ionization chamber (CIR, $chambre$ $d'ionization$ $de$ $référence$), CeBr$_{3}$ γ-ray detector with digital electronics and a second CeBr$_{3}$ detector with analog electronics and single-channel analyzer (SCA) counting. The value obtained for the $^{175}$Yb half-life is 4.1615(30) days which shows a 0.56% relative deviation to the last nuclear reference value (ENSDF 2004) and is supported with a detailed calculation of the associated uncertainty.

Published
2021

6. Determination of the gamma and X-ray emission intensities of terbium-161

Author

Frédéric Juget, Zeynep Talip, Thierry Buchillier, M. Teresa Durán, Youcef Nedjadi, Laurent Desorgher, François Bochud, Pascal Grundler, Nicholas P. van der Meulen, and Claude Bailat

Subjects
Radiation
Abstract

In this study, the gamma and X-ray emission intensities of

Published
2021

7. Results of the CCRI(II)-K2. H-3 key comparison 2018: Measurement of the activity concentration of a tritiated-water source

Author

P. De Felice, C Dutsov, Ole Nähle, Philippe Cassette, K Mitev, Eduardo García-Toraño, Youcef Nedjadi, T. Ziemek, Marcell P. Takács, Raphael Galea, A Arinc, P Oropesa Verdecia, Karsten Kossert, Marco Capogni, Juncheng Liang, Cassette, P., Arinc, A., Capogni, M., Dutsov, C., Galea, R., Garcia-Torano, E., Kossert, K., Liang, J., Mitev, K., Nahle, O., Nedjadi, Y., Verdecia, P. O., Takacs, M., Ziemek, T., Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), National Physical Laboratory [Teddington] (NPL), Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Sofia University 'St. Kliment Ohridski', National Research Council of Canada (NRC), Centro de Investigaciones Energéticas Medioambientales y Tecnológicas [Madrid] (CIEMAT), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), National Institute of Metrology [Beijing], Institut de radiophysique (IRA), Centro de Isotopos (CENTIS), and National Centre for Nuclear Research Radioisotope, Centre POLATOM

Subjects
Tritiated water, Chemistry, tritium, Radiochemistry, General Engineering, Primary activity measurement, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], intercomparison, chemistry.chemical_compound, metrology, radioactivity, Activity concentration, Key (cryptography), [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], ionizing radiation
Abstract

A comparison of the activity concentration measurement of a 3H2O solution was organized by the LNE-LNHB under the auspices of the CCRI(II). The solution was sent to thirteen laboratories and eleven measurement reports were received. The results, as well as relevant information on the measurement techniques, are presented and analysed in this paper. All results are consistent within uncertainties. As the solution was traceable to the solution used in the CCRI(II)-K2.H-3 comparison in 2009, the results of both comparisons are also presented. Main text 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).

Published
2020

8. Determination of the gamma and X-ray emission intensities of erbium-169

Author

Claude Bailat, Zeynep Talip, François Bochud, Frédéric Juget, Nicholas P. van der Meulen, M. Teresa Durán, J. Ulrich, T. Buchillier, and Youcef Nedjadi

Subjects
Radiation, Materials science, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, X-ray, chemistry.chemical_element, Germanium, 010403 inorganic & nuclear chemistry, 01 natural sciences, 030218 nuclear medicine & medical imaging, 0104 chemical sciences, 03 medical and health sciences, 0302 clinical medicine, Erbium-169, chemistry, Reference values, Atomic physics, Gamma ray spectrometry, Line (formation)
Abstract

The gamma and X-ray emission intensities of 169Er were determined using radionuclidically pure 169Er. The activity of the 169Er source was standardized by the triple-to-double-coincidence ratio technique. Three independent measurements were performed to measure the emission intensities using calibrated high-purity germanium spectrometers. The efficiencies were computed with the Monte Carlo method and validated using several experimental measurements. Final results present a large uncertainty reduction compared to previous evaluations. The emission intensities per decay of 169Er are reported as 1.401(40).10−5 for the 109.8 keV line and 1.513(19).10−6 for the 118.2 keV line. The values obtained for the X-ray lines show large discrepancies with the reference values.

Published
2021

9. Activity standardisation of 223Ra

Author

Laurent Desorgher, Claude Bailat, Youcef Nedjadi, François Bochud, Frédéric Juget, and T. Buchillier

Subjects
Physics, Radiation, Monte Carlo method, Liquid scintillation counting, Radiochemistry, Detector, 010403 inorganic & nuclear chemistry, 01 natural sciences, 030218 nuclear medicine & medical imaging, 0104 chemical sciences, 03 medical and health sciences, 0302 clinical medicine, Activity concentration, Standard uncertainty, Nuclide
Abstract

We report here on the primary activity standardisation of a223Ra dichloride solution in equilibrium with its decay daughters. Both the triple-to-double-coincidence-ratio (TDCR) method with an in-house TDCR detector and the CIEMAT-NIST efficiency tracing (CNET) technique with a commercial counter were used. The liquid scintillation efficiencies for both methods are about 6 while the activities they predict with about 0.4% relative standard uncertainty agree within 0.15%. For backup, the solution was also standardised with 4πγ NaI(Tl) integral counting with a well-type NaI(Tl) detector, and efficiencies computed by Monte Carlo simulations using the GEANT code. This simple technique, unused previously for this nuclide, yielded an activity concentration compatible with, but 1% lower than, the one determined by liquid scintillation counting.

Published
2021

10. On decay constants and orbital distance to the Sun—part III: beta plus and electron capture decay

Author

M. Bruggeman, Karsten Kossert, Timotheos Altzitzoglou, Stefaan Pommé, J. Lubbe, J. Golya, Youcef Nedjadi, Raphael Galea, R. Van Ammel, A. Ceccatelli, Mikael Hult, S. Bourke, H. Schrader, C Michotte, M.-N. Amiot, Matjaž Korun, W.M. van Wyngaardt, S Courte, Aldo Fazio, V. Chisté, M. I. Reinhard, H. Stroh, L. Verheyen, Branko Vodenik, Claude Bailat, M. Marouli, T. W. Jackson, P. De Felice, K.M. Ferreira, Frédéric Juget, B.R.S. Simpson, Sean Collins, François Bochud, J. Paepen, M.W. van Rooy, John Keightley, Ole Nähle, T. Buchillier, M.J. van Staden, T. Roy, JRC Institute for Reference Materials and Measurements [Geel] (IRMM), European Commission - Joint Research Centre [Geel] (JRC), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), Institut Universitaire de Radiophysique Appliquée, Bureau International des Poids et Mesures (BIPM), National Metrology Institute of South Africa, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Australian Nuclear Science and Technology Organisation [Australie] (ANSTO), National Research Council of Canada (NRC), National Physical Laboratory [Teddington] (NPL), International Atomic Energy Agency [Vienna] (IAEA), Centre d'Etude de l'Energie Nucléaire (SCK-CEN), Jozef Stefan Institute [Ljubljana] (IJS), Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, De Felice, P., Fazio, A., Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Electron capture, UNCERTAINTY, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010403 inorganic & nuclear chemistry, 7. Clean energy, 01 natural sciences, neutrino, 0103 physical sciences, Exponential decay, 010303 astronomy & astrophysics, Engineering(all), Physics, Radionuclide, half-life, decay constant, Sun, uncertainty, radioactivity, HALF-LIFE, GAMMA-RAY SPECTROMETRY, IONIZATION-CHAMBER, General Engineering, Half-life, SOLAR INFLUENCE, Beta decay, 0104 chemical sciences, Amplitude, 13. Climate action, Neutrino, Atomic physics, Radioactive decay
Abstract

International audience; The hypothesis that seasonal changes in proximity to the Sun cause variation of decay constants at permille level has been tested for radionuclides disintegrating through electron capture and beta plus decay. Activity measurements of Na-22, Mn-54, Fe-55, Co-57, Zn-65, Sr82+85, Sr-90, Cd-109, Sb-124, Ba-133, Eu-152, and Bi-207 sources were repeated over periods from 200 d up to more than four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. Oscillations in phase with Earth's orbital distance to the sun could not be observed within 10(-4)-10(-5) range precision. The most stable activity measurements of beta(+) and EC decaying sources set an upper limit of 0.006% or less to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months.

Published
2016

11. Determining the activity of 241Pu by liquid scintillation counting

Author

Youcef Nedjadi, J. A. Corcho Alvarado, and François Bochud

Subjects
Physics, Quenching, business.industry, Health, Toxicology and Mutagenesis, Liquid scintillation counting, Counting efficiency, Public Health, Environmental and Occupational Health, Pu-241, CIEMAT/NIST, ENVIRONMENTAL-SAMPLES, MARINE SAMPLES, STANDARDIZATION, SPECTROMETRY, SOILS, Tracing, Pollution, Analytical Chemistry, Optics, Nuclear Energy and Engineering, Calibration, NIST, Radiology, Nuclear Medicine and imaging, business, Spectroscopy
Abstract

Liquid scintillation counting (LSC) is one of the most widely used methods for determining the activity of 241Pu. One of the main challenges of this counting method is the efficiency calibration of the system for the low beta energies of 241Pu (E max = 20.8 keV). In this paper we compare the two most frequently used methods, the CIEMAT/NIST efficiency tracing (CNET) method and the experimental quench correction curve method. Both methods proved to be reliable, and agree within their uncertainties, for the expected quenching conditions of the sources.

Published
2018

12. On decay constants and orbital distance to the Sun—part I: alpha decay

Author

Timotheos Altzitzoglou, L. Verheyen, R. Van Ammel, H. Stroh, Youcef Nedjadi, J. Golya, V. Chisté, Claude Bailat, J. Lubbe, Mikael Hult, S. Bourke, S Courte, Ole Nähle, T. Roy, M.-N. Amiot, Stefaan Pommé, W.M. van Wyngaardt, Branko Vodenik, François Bochud, M. I. Reinhard, J. Paepen, M. Marouli, M. Bruggeman, C Michotte, P. De Felice, Sean Collins, M.W. van Rooy, T. Buchillier, A. Ceccatelli, Frédéric Juget, Raphael Galea, T. W. Jackson, K.M. Ferreira, B.R.S. Simpson, Aldo Fazio, M.J. van Staden, John Keightley, Karsten Kossert, H. Schrader, Matjaž Korun, JRC Institute for Reference Materials and Measurements [Geel] (IRMM), European Commission - Joint Research Centre [Geel] (JRC), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), Centre Hospitalier Universitaire Vaudois [Lausanne] (CHUV), Institut Universitaire de Radiophysique Appliquée, Bureau International des Poids et Mesures (BIPM), National Metrology Institute of South Africa, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Australian Nuclear Science and Technology Organisation [Australie] (ANSTO), National Research Council of Canada (NRC), National Physical Laboratory [Teddington] (NPL), International Atomic Energy Agency [Vienna] (IAEA), Centre d'Etude de l'Energie Nucléaire (SCK-CEN), Jozef Stefan Institute [Ljubljana] (IJS), Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, De Felice, P., Fazio, A., Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
EXPONENTIAL DECAY, half-life, non-exponential decay, RADIONUCLIDE metrology, Astrophysics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010403 inorganic & nuclear chemistry, 01 natural sciences, 7. Clean energy, HALF-LIFE MEASUREMENTS, Nuclear physics, neutrino, 0103 physical sciences, IONIZATION CHAMBERS, Nuclide, Exponential decay, Engineering(all), Physics, Range (particle radiation), 010308 nuclear & particles physics, General Engineering, Sun, Half-life, SOLAR INFLUENCE, SEASONAL-VARIATIONS, 0104 chemical sciences, Amplitude, NUCLEAR DECAY, PRIMARY STANDARDIZATION, 13. Climate action, radioactivity, decay constant, High Energy Physics::Experiment, Alpha decay, Neutrino, Radioactive decay
Abstract

International audience; Claims that proximity to the Sun causes variation of decay constants at permille level have been investigated for alpha decaying nuclides. Repeated decay rate measurements of Po-209, Ra-226, Th-228, U-230, and Am-241 sources were performed over periods of 200 d up to two decades at various nuclear metrology institutes around the globe. Residuals from the exponential decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ in amplitude and phase from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha decaying sources set an upper limit between 0.0006% and 0.006% to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months. Oscillations in phase with Earth's orbital distance to the sun could not be observed within 10(-5)-10(-6) range precision.

Published
2017

13. On decay constants and orbital distance to the Sun—part II: beta minus decay

Author

François Bochud, R. Van Ammel, V. Chisté, S Courte, T. Buchillier, Karsten Kossert, W.M. van Wyngaardt, J. Paepen, Stefaan Pommé, M. I. Reinhard, Branko Vodenik, S. Bourke, M.-N. Amiot, Mikael Hult, H. Stroh, J. Lubbe, Claude Bailat, H. Schrader, Matjaž Korun, T. Roy, M. Bruggeman, C Michotte, Aldo Fazio, M.W. van Rooy, M. Marouli, P. De Felice, Raphael Galea, John Keightley, Frédéric Juget, L. Verheyen, Timotheos Altzitzoglou, Youcef Nedjadi, Ole Nähle, Sean Collins, M.J. van Staden, J. Golya, A. Ceccatelli, T. W. Jackson, K.M. Ferreira, B.R.S. Simpson, JRC Institute for Reference Materials and Measurements [Geel] (IRMM), European Commission - Joint Research Centre [Geel] (JRC), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), Institut Universitaire de Radiophysique Appliquée, Bureau International des Poids et Mesures (BIPM), National Metrology Institute of South Africa, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Australian Nuclear Science and Technology Organisation [Australie] (ANSTO), National Research Council of Canada (NRC), National Physical Laboratory [Teddington] (NPL), International Atomic Energy Agency [Vienna] (IAEA), Centre d'Etude de l'Energie Nucléaire (SCK-CEN), Jozef Stefan Institute [Ljubljana] (IJS), Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, De Felice, P., Fazio, A., Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
half-life, non-exponential decay, Instrumentation, Phase (waves), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, UNCERTAINTIES, Nuclear physics, Theoretical physics, neutrino, CS-137, decay constant, Sun, radioactivity, 0103 physical sciences, Nuclide, RATES, Exponential decay, 010303 astronomy & astrophysics, Engineering(all), Physics, 010308 nuclear & particles physics, IONIZATION-CHAMBER, General Engineering, Half-life, SOLAR INFLUENCE, Beta decay, Amplitude, High Energy Physics::Experiment, Neutrino
Abstract

International audience; Claims that proximity to the Sun causes variations of decay constants at the permille level have been investigated for beta-minus decaying nuclides. Repeated activity measurements of H-3, C-14, Co-60, Kr-85, Sr-90, Sb-124, Cs-134, Cs-137, and Eu-154 sources were performed over periods of 259 d up to 5 decades at various nuclear metrology institutes. Residuals from the exponential decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ in amplitude and phase from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within 10(-4)-10(-5) range precision. The most stable activity measurements of beta-decaying sources set an upper limit of 0.003%-0.007% to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months.

Published
2017

14. Evidence against solar influence on nuclear decay constants

Author

Karsten Kossert, Denis E. Bergeron, M. Marouli, P. De Felice, S. Bourke, L. Verheyen, M.W. van Rooy, M.-N. Amiot, François Bochud, H. Stroh, Stefaan Pommé, Timotheos Altzitzoglou, Ryan P. Fitzgerald, Youcef Nedjadi, Frédéric Juget, R. Van Ammel, M. Bruggeman, T. W. Jackson, Raphael Galea, S Courte, J. Golya, K.M. Ferreira, Aldo Fazio, V. Chisté, Branko Vodenik, Michael P. Unterweger, John Keightley, B.R.S. Simpson, Claude Bailat, W.M. van Wyngaardt, J. Paepen, H. Schrader, Matjaž Korun, Ole Nähle, M. I. Reinhard, C Michotte, A. Ceccatelli, Leticia S. Pibida, J. Lubbe, T. Buchillier, T. Roy, M.J. van Staden, Sean Collins, Mikael Hult, Bureau International des Poids et Mesures (BIPM), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Fazio, A., European Commission - Joint Research Centre [Geel] (JRC), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), Institut de radiophysique (IRA), Radioactivity Standards Laboratory (NMISA), Laboratorio Tecnologie dei Materiali Faenza, ENEA, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Australian Nuclear Science and Technology Organisation [Australie] (ANSTO), National Research Council of Canada (NRC), National Physical Laboratory [Teddington] (NPL), Environment Laboratories (IAEA), International Atomic Energy Agency [Vienna] (IAEA), National Institute of Standards and Technology [Gaithersburg] (NIST), Centre d'Etude de l'Energie Nucléaire (SCK-CEN), Jozef Stefan Institute [Ljubljana] (IJS), Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Nuclear and High Energy Physics, Electron capture, Decay constant, Astrophysics, Neutrino, Half-life, Uncertainty, Radioactivity, Sun, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, alpha-rays, Article, 010309 optics, Nuclear physics, Becquerel, 0103 physical sciences, beta-rays, Exponential decay, Neutrinos, 010306 general physics, Physics, lcsh:QC1-999, Exponential function, Amplitude, 13. Climate action, ionizing radiation, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Radioactive decay, lcsh:Physics
Abstract

International audience; The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10−6 to 10−5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

Published
2016

15. The Duffin-Kemmer-Petiau oscillator

Author

Roger Barrett and Youcef Nedjadi

Subjects
Physics, Angular momentum, Scalar (mathematics), Anharmonicity, General Physics and Astronomy, Statistical and Nonlinear Physics, Nonlinear Sciences::Exactly Solvable and Integrable Systems, Quantum harmonic oscillator, Total angular momentum quantum number, Quantum mechanics, Mathematical Physics, Harmonic oscillator, Eigenvalues and eigenvectors, Boson
Abstract

In view of the current interest in relativistic spin-1 systems and the recent work on the Dirac oscillator, we introduce the Duffin-Kemmer-Petiau (DKP) equation obtained by using an external potential linear in r. Since the spin-0 representation leads to a harmonic oscillator in the non-relativistic limit and becomes an harmonic oscillator with a spin-orbit coupling of the Thomas form for vector bosons, we call the equation the DKP oscillator. This oscillator is a relativistic generalization of the quantum harmonic oscillator for scalar and vector bosons. We show that it conserves total angular momentum and that it is exactly solvable for both scalar and vector DKP bosons. We calculate and discuss the eigenvalues and eigenstates of the DKP oscillator in the spin-0 and spin-1 representations.

Published
1994

16. Development and validation of a double focalizing magnetic spectrometer for beta spectrum measurements

Author

Guido Haefeli, Claude Bailat, Giuseppe Lorusso, Frédéric Juget, François Bochud, and Youcef Nedjadi

Subjects
Physics, beta shape measurement, Nuclear and High Energy Physics, Spectrometer, business.industry, Detector, Electron, 010403 inorganic & nuclear chemistry, magnetic spectrometer, 01 natural sciences, cl-36, Spectral line, 030218 nuclear medicine & medical imaging, 0104 chemical sciences, Magnetic field, 03 medical and health sciences, 0302 clinical medicine, Optics, Beta (plasma physics), acquisition system, Calibration, business, Instrumentation, Energy (signal processing)
Abstract

In the framework of the EMPIR project MetroBeta, the development and optimization of a double focalizing magnetic spectrometer have been realized in order to measure the beta spectra shape. The acquisition is designed to perform,after focalization by the magnetic field, an energy selection using a window on the deposited energy in the Si detector. The energy calibration is performed using conversion electrons from 109Cd, 137Cs, 133Ba and 207Bi and the measured energy resolution is 1.3% at 1 MeV. The efficiency is measured experimentally using a 204Tl source and is used to reconstruct the spectrum shape for beta emitters with end-point energy up to 750 keV. Two beta emitters with allowed transitions, 134Cs and 60Co, are used to validate the measurement and the reconstruction method. Finally the measurement of the beta shape of 36Cl, a non-unique 2nd forbidden transition is presented.

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