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6 results on '"IONIZATION-CHAMBER"'

1. 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

2. Novel methodologies for dosimetry audits: Adapting to advanced radiotherapy techniques

Author

Ciències Mèdiques Bàsiques, Universitat Rovira i Virgili, Pasler, M; Hernandez, V; Jornet, N; Clark, CH, Ciències Mèdiques Bàsiques, Universitat Rovira i Virgili, and Pasler, M; Hernandez, V; Jornet, N; Clark, CH

Abstract

With new radiotherapy techniques, treatment delivery is becoming more complex and accordingly, these treatment techniques require dosimetry audits to test advanced aspects of the delivery to ensure best practice and safe patient treatment.This review of novel methodologies for dosimetry audits for advanced radiotherapy techniques includes recent developments and future techniques to be applied in dosimetry audits. Phantom-based methods (i.e. phantom-detector combinations) including independent audit equipment and local measurement equipment as well as phantom-less methods (i.e. portal dosimetry, transmission detectors and log files) are presented and discussed. Methodologies for both conventional linear accelerator (linacs) and new types of delivery units, i.e. Tomotherapy, stereotactic devices and MR-linacs, are reviewed.Novel dosimetry audit techniques such as portal dosimetry or log file evaluation have the potential to allow parallel auditing (i.e. performing an audit at multiple institutions at the same time), automation of data analysis and evaluation of multiple steps of the radiotherapy treatment chain. These methods could also significantly reduce the time needed for audit and increase the information gained. However, to maximise the potential, further development and harmonisation of dosimetry audit techniques are required before these novel methodologies can be applied.

Published
2018

3. Large-volume and room-temperature gamma spectrometer for environmental radiation monitoring

Author

Emmanuel Rohee, Jonathan Dumazert, Karim Boudergui, Romain Coulon, Tola Tith, Laboratoire Capteurs et Architectures Electroniques (LCAE), 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, Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), and 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))

Subjects
Xenon, Nuclear engineering, RAY SPECTROMETER, Analytical chemistry, chemistry.chemical_element, NUCLEAR, Radiation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Environmental, Reliability (semiconductor), HIGH-PRESSURE XENON, SEARCH, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010303 astronomy & astrophysics, DETECTOR, Physics, SPECTROSCOPY, Spectrometer, 010308 nuclear & particles physics, Spectrometry, Detector, IONIZATION-CHAMBER, LIQUID XENON, lcsh:TK9001-9401, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Nuclear Energy and Engineering, chemistry, GAS, Ionization chamber, Measuring instrument, Radiation monitoring, lcsh:Nuclear engineering. Atomic power, ionizing radiation, HIGH-RESOLUTION
Abstract

International audience; The use of a room-temperature gamma spectrometer is an issue in environmental radiation monitoring. To monitor radionuclides released around a nuclear power plant, suitable instruments giving fast and reliable information are required. High-pressure xenon (HPXe) chambers have range of resolution and efficiency equivalent to those of other medium resolution detectors such as those using NaI(Tl), CdZnTe, and LaBr3:Ce. An HPXe chamber could be a cost-effective alternative, assuming temperature stability and reliability. The CEA LIST actively studied and developed HPXe-based technology applied for environmental monitoring. Xenon purification and conditioning was performed. The design of a 4-L HPXe detector was performed to minimize the detector capacitance and the required power supply. Simulations were done with the MCNPX2.7 particle transport code to estimate the intrinsic efficiency of the HPXe detector. A behavioral study dealing with ballistic deficits and electronic noise will be utilized to provide perspective for further analysis.

Published
2017

4. 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

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