Lars-Erik De Geer - Academia.edu (original) (raw)
Papers by Lars-Erik De Geer
Journal of Environmental Radioactivity, 1990
... Aaltonen, Kari Sinkko, Aino Rantavaara Finnish Centre for Radiation and Nuclear Safety, PO Bo... more ... Aaltonen, Kari Sinkko, Aino Rantavaara Finnish Centre for Radiation and Nuclear Safety, PO Box 268, SF00101 Helsinki, Finland Sven Poul Nielsen ... cows' milk from the particulate iodine concentrations in air, a dry deposition velocity of 0.5 cm s (Erlandsson Isaksson, 1988), an ...
... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson Natio... more ... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson National Defence Research Institute FOA 215, Nuclear Detection Box ... This sample was aglass-fiber filter through which 78 740m3 of ground level air had passed between April 25, 07: ...
Atmospheric Environment, 2003
Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring sys... more Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring system comprising different verification technologies is currently being set up. The network will include 80 radionuclide (RN) stations distributed all over the globe that measure treaty-relevant radioactive species. While the seismic subsystem cannot distinguish between chemical and nuclear explosions, RN monitoring would provide the ''smoking gun'' of a possible treaty violation. Atmospheric transport modelling (ATM) will be an integral part of CTBT verification, since it provides a geo-temporal location capability for the RN technology. In this paper, the basic concept for the future ATM software system to be installed at the International Data Centre is laid out. The system is based on the operational computation of multi-dimensional source-receptor sensitivity fields for all RN samples by means of adjoint tracer transport modelling. While the source-receptor matrix methodology has already been applied in the past, the system that we suggest will be unique and unprecedented, since it is global, real-time and aims at uncovering source scenarios that are compatible with measurements. Furthermore, it has to deal with source dilution ratios that are by orders of magnitude larger than in typical transport model applications. This new verification software will need continuous scientific attention, and may well provide a prototype system for future applications in areas of environmental monitoring, emergency response and verification of other international agreements and treaties. r
Science & Global Security, 2012
Between 13 and 23 May 2010, four atmospheric radionuclide surveillance stations, in South Korea, ... more Between 13 and 23 May 2010, four atmospheric radionuclide surveillance stations, in South Korea, Japan, and the Russian Federation, detected xenon and xenon daughter radionuclides in concentrations up to 10 and 0.1 mBq/m3 respectively. All these measurements were made in air masses that had passed over North Korea a few days earlier. This article shows that these radionuclide observations are consistent with a North Korean low-yield nuclear test on 11 May 2010, even though no seismic signals from such a test have been detected. Appendix 1 presents a detailed analysis of the radioxenon data and Appendix 2 describes a hypothetical nuclear test scenario consistent with this analysis, including the possibility that the test used uranium-235 rather than plutonium-239. The analysis suggests that the technical and analytical basis to detect small nuclear tests using radionuclide signatures may be more developed than is generally assumed.
IEEE Transactions on Nuclear Science, 1982
IEEE Transactions on Nuclear Science, 1987
... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson Natio... more ... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson National Defence Research Institute FOA 215, Nuclear Detection Box ... This sample was aglass-fiber filter through which 78 740m3 of ground level air had passed between April 25, 07: ...
Applied Radiation and Isotopes, 2004
Currie Hypothesis testing is applied to gamma-ray spectral data, where an optimum part of the pea... more Currie Hypothesis testing is applied to gamma-ray spectral data, where an optimum part of the peak is used and the background is considered well known from nearby channels. With this, the risk of making Type I errors is about 100 times lower than commonly assumed. A programme, PeakMaker, produces random peaks with given characteristics on the screen and calculations are done to facilitate a full use of Poisson statistics in spectrum analyses.
Atmospheric Environment, 2003
Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring sys... more Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring system comprising different verification technologies is currently being set up. The network will include 80 radionuclide (RN) stations distributed all over the globe that measure treaty-relevant radioactive species. While the seismic subsystem cannot distinguish between chemical and nuclear explosions, RN monitoring would provide the ''smoking gun'' of a possible treaty violation. Atmospheric transport modelling (ATM) will be an integral part of CTBT verification, since it provides a geo-temporal location capability for the RN technology. In this paper, the basic concept for the future ATM software system to be installed at the International Data Centre is laid out. The system is based on the operational computation of multi-dimensional source-receptor sensitivity fields for all RN samples by means of adjoint tracer transport modelling. While the source-receptor matrix methodology has already been applied in the past, the system that we suggest will be unique and unprecedented, since it is global, real-time and aims at uncovering source scenarios that are compatible with measurements. Furthermore, it has to deal with source dilution ratios that are by orders of magnitude larger than in typical transport model applications. This new verification software will need continuous scientific attention, and may well provide a prototype system for future applications in areas of environmental monitoring, emergency response and verification of other international agreements and treaties. r G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ]
Journal of Geophysical Research, 2006
As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote reg... more As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote regions at high northern latitudes: Longyearbyen, Spitsbergen, Norway (78.2°N), and Yellowknife, Canada (62.5°N). With one exception, both stations are 2000 km or more from any single known stationary nuclear facility. Nevertheless, the short-lived anthropogenic radionuclide 133Xe (t$_{^{1}\!/\!_{2}}$ = 5.24 days) has been detected on a
Journal of Geophysical Research, 2006
As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote reg... more As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote regions at high northern latitudes: Longyearbyen, Spitsbergen, Norway (78.2°N), and Yellowknife, Canada (62.5°N). With one exception, both stations are 2000 km or more from any single known stationary nuclear facility. Nevertheless, the short-lived anthropogenic radionuclide 133Xe (t$_{^{1}\!/\!_{2}}$ = 5.24 days) has been detected on a
Pure and Applied Geophysics, 2010
Activity concentration data from ambient radioxenon measurements in ground level air, which were ... more Activity concentration data from ambient radioxenon measurements in ground level air, which were carried out in Europe in the framework of the International Noble Gas Experiment (INGE) in support of the development and build-up of a radioxenon monitoring network for the Comprehensive Nuclear-Test-Ban Treaty verification regime are presented and discussed. Six measurement stations provided data from 5 years of measurements performed between 2003 and 2008: Longyearbyen (Spitsbergen, Norway), Stockholm (Sweden), Dubna (Russian Federation), Schauinsland Mountain (Germany), Bruyères-le-Châtel and Marseille (both France). The noble gas systems used within the INGE are designed to continuously measure low concentrations of the four radioxenon isotopes which are most relevant for detection of nuclear explosions: 131mXe, 133mXe, 133Xe and 135Xe with a time resolution less than or equal to 24 h and a minimum detectable concentration of 133Xe less than 1 mBq/m3. This European cluster of six stations is particularly interesting because it is highly influenced by a high density of nuclear power reactors and some radiopharmaceutical production facilities. The activity concentrations at the European INGE stations are studied to characterise the influence of civilian releases, to be able to distinguish them from possible nuclear explosions. It was found that the mean activity concentration of the most frequently detected isotope, 133Xe, was 5–20 mBq/m3 within Central Europe where most nuclear installations are situated (Bruyères-le-Châtel and Schauinsland), 1.4–2.4 mBq/m3 just outside that region (Stockholm, Dubna and Marseille) and 0.2 mBq/m3 in the remote polar station of Spitsbergen. No seasonal trends could be observed from the data. Two interesting events have been examined and their source regions have been identified using atmospheric backtracking methods that deploy Lagrangian particle dispersion modelling and inversion techniques. The results are consistent with known releases of a radiopharmaceutical facility.
Atmospheric Environment, 2007
Among the different technologies applied to verify compliance with the Comprehensive Nuclear-Test... more Among the different technologies applied to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), radionuclide monitoring by means of a 80 stations global network may be the only technology capable of detecting ambitiously disguised, or decoupled, nuclear explosion. In preparation for such a case the PTS performs since August 2002 source attribution by receptor oriented particle trajectory modelling to help determine the region from which suspicious radio nuclides may originate. In doing so a diagnostic 3Dtransport model (FLEXPART, Stohl et al., 1998) is integrated backward in time based on global analysis wind fields yielding global fields of surface level adjoint concentrations stored in 3h frequency and at 1 0 ×1 0 horizontal resolution. This output constitutes the set of so-called source-receptor sensitivity (SRS) fields specific for each of the 80-radionuclide samples collected daily. The underlying methodology and efforts to explore its uncertainty shall be examined in the following.
Journal of Environmental Radioactivity, 1990
... Aaltonen, Kari Sinkko, Aino Rantavaara Finnish Centre for Radiation and Nuclear Safety, PO Bo... more ... Aaltonen, Kari Sinkko, Aino Rantavaara Finnish Centre for Radiation and Nuclear Safety, PO Box 268, SF00101 Helsinki, Finland Sven Poul Nielsen ... cows' milk from the particulate iodine concentrations in air, a dry deposition velocity of 0.5 cm s (Erlandsson Isaksson, 1988), an ...
... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson Natio... more ... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson National Defence Research Institute FOA 215, Nuclear Detection Box ... This sample was aglass-fiber filter through which 78 740m3 of ground level air had passed between April 25, 07: ...
Atmospheric Environment, 2003
Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring sys... more Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring system comprising different verification technologies is currently being set up. The network will include 80 radionuclide (RN) stations distributed all over the globe that measure treaty-relevant radioactive species. While the seismic subsystem cannot distinguish between chemical and nuclear explosions, RN monitoring would provide the ''smoking gun'' of a possible treaty violation. Atmospheric transport modelling (ATM) will be an integral part of CTBT verification, since it provides a geo-temporal location capability for the RN technology. In this paper, the basic concept for the future ATM software system to be installed at the International Data Centre is laid out. The system is based on the operational computation of multi-dimensional source-receptor sensitivity fields for all RN samples by means of adjoint tracer transport modelling. While the source-receptor matrix methodology has already been applied in the past, the system that we suggest will be unique and unprecedented, since it is global, real-time and aims at uncovering source scenarios that are compatible with measurements. Furthermore, it has to deal with source dilution ratios that are by orders of magnitude larger than in typical transport model applications. This new verification software will need continuous scientific attention, and may well provide a prototype system for future applications in areas of environmental monitoring, emergency response and verification of other international agreements and treaties. r
Science & Global Security, 2012
Between 13 and 23 May 2010, four atmospheric radionuclide surveillance stations, in South Korea, ... more Between 13 and 23 May 2010, four atmospheric radionuclide surveillance stations, in South Korea, Japan, and the Russian Federation, detected xenon and xenon daughter radionuclides in concentrations up to 10 and 0.1 mBq/m3 respectively. All these measurements were made in air masses that had passed over North Korea a few days earlier. This article shows that these radionuclide observations are consistent with a North Korean low-yield nuclear test on 11 May 2010, even though no seismic signals from such a test have been detected. Appendix 1 presents a detailed analysis of the radioxenon data and Appendix 2 describes a hypothetical nuclear test scenario consistent with this analysis, including the possibility that the test used uranium-235 rather than plutonium-239. The analysis suggests that the technical and analytical basis to detect small nuclear tests using radionuclide signatures may be more developed than is generally assumed.
IEEE Transactions on Nuclear Science, 1982
IEEE Transactions on Nuclear Science, 1987
... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson Natio... more ... Ingemar Vintersved, Lars-Erik De Geer, Bjbrn Bjurrnan, Rune Arntsing, and Siv Jakobsson National Defence Research Institute FOA 215, Nuclear Detection Box ... This sample was aglass-fiber filter through which 78 740m3 of ground level air had passed between April 25, 07: ...
Applied Radiation and Isotopes, 2004
Currie Hypothesis testing is applied to gamma-ray spectral data, where an optimum part of the pea... more Currie Hypothesis testing is applied to gamma-ray spectral data, where an optimum part of the peak is used and the background is considered well known from nearby channels. With this, the risk of making Type I errors is about 100 times lower than commonly assumed. A programme, PeakMaker, produces random peaks with given characteristics on the screen and calculations are done to facilitate a full use of Poisson statistics in spectrum analyses.
Atmospheric Environment, 2003
Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring sys... more Under the provisions of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global monitoring system comprising different verification technologies is currently being set up. The network will include 80 radionuclide (RN) stations distributed all over the globe that measure treaty-relevant radioactive species. While the seismic subsystem cannot distinguish between chemical and nuclear explosions, RN monitoring would provide the ''smoking gun'' of a possible treaty violation. Atmospheric transport modelling (ATM) will be an integral part of CTBT verification, since it provides a geo-temporal location capability for the RN technology. In this paper, the basic concept for the future ATM software system to be installed at the International Data Centre is laid out. The system is based on the operational computation of multi-dimensional source-receptor sensitivity fields for all RN samples by means of adjoint tracer transport modelling. While the source-receptor matrix methodology has already been applied in the past, the system that we suggest will be unique and unprecedented, since it is global, real-time and aims at uncovering source scenarios that are compatible with measurements. Furthermore, it has to deal with source dilution ratios that are by orders of magnitude larger than in typical transport model applications. This new verification software will need continuous scientific attention, and may well provide a prototype system for future applications in areas of environmental monitoring, emergency response and verification of other international agreements and treaties. r G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ] G. Wotawa et al. / Atmospheric Environment ]
Journal of Geophysical Research, 2006
As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote reg... more As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote regions at high northern latitudes: Longyearbyen, Spitsbergen, Norway (78.2°N), and Yellowknife, Canada (62.5°N). With one exception, both stations are 2000 km or more from any single known stationary nuclear facility. Nevertheless, the short-lived anthropogenic radionuclide 133Xe (t$_{^{1}\!/\!_{2}}$ = 5.24 days) has been detected on a
Journal of Geophysical Research, 2006
As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote reg... more As part of the International Noble Gas Experiment (INGE) two stations were deployed in remote regions at high northern latitudes: Longyearbyen, Spitsbergen, Norway (78.2°N), and Yellowknife, Canada (62.5°N). With one exception, both stations are 2000 km or more from any single known stationary nuclear facility. Nevertheless, the short-lived anthropogenic radionuclide 133Xe (t$_{^{1}\!/\!_{2}}$ = 5.24 days) has been detected on a
Pure and Applied Geophysics, 2010
Activity concentration data from ambient radioxenon measurements in ground level air, which were ... more Activity concentration data from ambient radioxenon measurements in ground level air, which were carried out in Europe in the framework of the International Noble Gas Experiment (INGE) in support of the development and build-up of a radioxenon monitoring network for the Comprehensive Nuclear-Test-Ban Treaty verification regime are presented and discussed. Six measurement stations provided data from 5 years of measurements performed between 2003 and 2008: Longyearbyen (Spitsbergen, Norway), Stockholm (Sweden), Dubna (Russian Federation), Schauinsland Mountain (Germany), Bruyères-le-Châtel and Marseille (both France). The noble gas systems used within the INGE are designed to continuously measure low concentrations of the four radioxenon isotopes which are most relevant for detection of nuclear explosions: 131mXe, 133mXe, 133Xe and 135Xe with a time resolution less than or equal to 24 h and a minimum detectable concentration of 133Xe less than 1 mBq/m3. This European cluster of six stations is particularly interesting because it is highly influenced by a high density of nuclear power reactors and some radiopharmaceutical production facilities. The activity concentrations at the European INGE stations are studied to characterise the influence of civilian releases, to be able to distinguish them from possible nuclear explosions. It was found that the mean activity concentration of the most frequently detected isotope, 133Xe, was 5–20 mBq/m3 within Central Europe where most nuclear installations are situated (Bruyères-le-Châtel and Schauinsland), 1.4–2.4 mBq/m3 just outside that region (Stockholm, Dubna and Marseille) and 0.2 mBq/m3 in the remote polar station of Spitsbergen. No seasonal trends could be observed from the data. Two interesting events have been examined and their source regions have been identified using atmospheric backtracking methods that deploy Lagrangian particle dispersion modelling and inversion techniques. The results are consistent with known releases of a radiopharmaceutical facility.
Atmospheric Environment, 2007
Among the different technologies applied to verify compliance with the Comprehensive Nuclear-Test... more Among the different technologies applied to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), radionuclide monitoring by means of a 80 stations global network may be the only technology capable of detecting ambitiously disguised, or decoupled, nuclear explosion. In preparation for such a case the PTS performs since August 2002 source attribution by receptor oriented particle trajectory modelling to help determine the region from which suspicious radio nuclides may originate. In doing so a diagnostic 3Dtransport model (FLEXPART, Stohl et al., 1998) is integrated backward in time based on global analysis wind fields yielding global fields of surface level adjoint concentrations stored in 3h frequency and at 1 0 ×1 0 horizontal resolution. This output constitutes the set of so-called source-receptor sensitivity (SRS) fields specific for each of the 80-radionuclide samples collected daily. The underlying methodology and efforts to explore its uncertainty shall be examined in the following.