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Andersson Sundén, Erik
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Publications (10 of 51) Show all publications
Tarrio, D., Prokofiev, A. V., Gustavsson, C., Jansson, K., Andersson Sundén, E., Al-Adili, A. & Pomp, S. (2017). Characterization of the Medley setup for measurements of neutron-induced fission cross sections at the GANIL-NFS facility. Paper presented at ND 2016: International Conference on Nuclear Data for Science and Technology. EPJ Web of Conferences, 146, Article ID 03026.
Open this publication in new window or tab >>Characterization of the Medley setup for measurements of neutron-induced fission cross sections at the GANIL-NFS facility
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2017 (English)In: EPJ Web of Conferences, ISSN 2101-6275, E-ISSN 2100-014X, Vol. 146, 03026Article in journal (Refereed) Published
Abstract [en]

Neutron-induced fission cross sections of 235U and 238U are widely used as standards for monitoring of neutron beams and fields. An absolute measurement of these cross sections at an absolute scale, i.e., versus the H(n,p) scattering cross section, is planned with the white neutron beam under construction at the Neutrons For Science (NFS) facility in GANIL. The experimental setup, based on PPACs and ΔE-ΔE-E telescopes containing Silicon and CsI(Tl) detectors, is described. The expected uncertainties are discussed.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-338734 (URN)10.1051/epjconf/201714603026 (DOI)
Conference
ND 2016: International Conference on Nuclear Data for Science and Technology
Available from: 2018-01-12 Created: 2018-01-12 Last updated: 2018-01-17Bibliographically approved
Branger, E., Grape, S., Jacobsson, S., Jansson, P. & Andersson Sundén, E. (2017). Comparison of prediction models for Cherenkov light emissions from nuclear fuel assemblies. Journal of Instrumentation, 12, Article ID P06007.
Open this publication in new window or tab >>Comparison of prediction models for Cherenkov light emissions from nuclear fuel assemblies
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2017 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, P06007Article in journal (Refereed) Published
Abstract [en]

The Digital Cherenkov Viewing Device (DCVD) is a tool used by nuclear safeguards inspectors to verify irradiated nuclear fuel assemblies in wet storage based on the Cherenkov light produced by the assembly. Verification that no rods have been substituted in the fuel, so-called partial-defect verification, is made by comparing the intensity measured with a DCVD with a predicted intensity, based on operator fuel declaration. The prediction model currently used by inspectors is based on simulations of Cherenkov light production in a BWR 8x8 geometry. This work investigates prediction models based on simulated Cherenkov light production in a BWR 8x8 and a PWR 17x17 assembly, as well as a simplified model based on a single rod in water. Cherenkov light caused by both fission product gamma and beta decays were considered.The simulations reveal that there are systematic differences between the models, most noticeably with respect to the fuel assembly cooling time. Consequently, a prediction model that is based on another fuel assembly configuration than the fuel type being measured, will result in systematic over or underestimation of short-cooled fuel as opposed to long-cooled fuel. While a simplified model may be accurate enough for fuel assemblies with fairly homogeneous cooling times, the prediction models may differ by up to 18 \,\% for more heterogeneous fuel. Accordingly, these investigations indicate that the currently used model may need to be exchanged with a set of more detailed, fuel-type specific models, in order minimize the model dependant systematic deviations.

Keyword
Cherenkov and transition radiation; Cherenkov detectors; Search for radioactive and; fissile materials; Interaction of radiation with matter
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-309739 (URN)10.1088/1748-0221/12/06/P06007 (DOI)000405090600007 ()
Funder
Swedish Radiation Safety Authority, SSM2012-2750Swedish National Infrastructure for Computing (SNIC), p2007011
Available from: 2016-12-07 Created: 2016-12-07 Last updated: 2017-10-24Bibliographically approved
Binda, F., Eriksson, J., Ericsson, G., Hellesen, C., Conroy, S., Nocente, M. & Andersson Sundén, E. (2017). Generation of the neutron response function of an NE213 scintillator for fusion applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 866, 222-229.
Open this publication in new window or tab >>Generation of the neutron response function of an NE213 scintillator for fusion applications
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2017 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 866, 222-229 p.Article in journal (Refereed) Published
Abstract [en]

In this work we present a method to evaluate the neutron response function of an NE213 liquid scintillator. This method is particularly useful when the proton light yield function of the detector has not been measured, since it is based on a proton light yield function taken from literature, MCNPX simulations, measurements of gammarays from a calibration source and measurements of neutrons from fusion experiments with ohmic plasmas. The inclusion of the latter improves the description of the proton light yield function in the energy range of interest (around 2.46 MeV). We apply this method to an NE213 detector installed at JET, inside the radiation shielding of the magnetic proton recoil (MPRu) spectrometer, and present the results from the calibration along with some examples of application of the response function to perform neutron emission spectroscopy (NES) of fusion plasmas. We also investigate how the choice of the proton light yield function affects the NES analysis, finding that the result does not change significantly. This points to the fact that the method for the evaluation of the neutron response function is robust and gives reliable results.

Keyword
NE213 scintillator, Neutron spectroscopy, Response function, Proton light yield
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-330537 (URN)10.1016/j.nima.2017.04.023 (DOI)000407863700029 ()
Available from: 2017-10-04 Created: 2017-10-04 Last updated: 2017-11-16Bibliographically approved
Branger, E., Grape, S., Jacobsson, S., Jansson, P. & Andersson Sundén, E. (2017). On Cherenkov light production by irradiated nuclear fuel rods. Journal of Instrumentation, 12, Article ID T06001.
Open this publication in new window or tab >>On Cherenkov light production by irradiated nuclear fuel rods
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2017 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, T06001Article in journal (Refereed) Published
Abstract [en]

Safeguards verification of irradiated nuclear fuel assemblies in wet storage is frequently done by measuring the Cherenkov light in the surrounding water produced due to radioactive decays of fission products in the fuel. This paper accounts for the physical processes behind the Cherenkov light production caused by a single fuel rod in wet storage, and simulations are presented that investigate to what extent various properties of the rod affect the Cherenkov light production. The results show that the fuel properties has a noticeable effect on the Cherenkov light production, and thus that the prediction models for Cherenkov light production which are used in the safeguards verifications could potentially be improved by considering these properties.It is concluded that the dominating source of the Cherenkov light is gamma-ray interactions with electrons in the surrounding water. Electrons created from beta decay may also exit the fuel and produce Cherenkov light, and e.g. Y-90 was identified as a possible contributor to significant levels of the measurable Cherenkov light in long-cooled fuel. The results also show that the cylindrical, elongated fuel rod geometry results in a non-isotropic Cherenkov light production, and the light component parallel to the rod's axis exhibits a dependence on gamma-ray energy that differs from the total intensity, which is of importance since the typical safeguards measurement situation observes the vertical light component. It is also concluded that the radial distributions of the radiation sources in a fuel rod will affect the Cherenkov light production.

Keyword
Nuclear safeguards, Geant4, Cherenkov light, DCVD, Nuclear fuel rod
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-309736 (URN)10.1088/1748-0221/12/06/T06001 (DOI)000405090900001 ()
Funder
Swedish Radiation Safety Authority, SSM2012-2750Swedish National Infrastructure for Computing (SNIC), p2007011
Available from: 2016-12-07 Created: 2016-12-07 Last updated: 2017-10-10Bibliographically approved
Eriksson, J., Conroy, S., Andersson Sundén, E. & Hellesen, C. (2016). Calculating fusion neutron energy spectra from arbitrary reactant distributions. Computer Physics Communications, 199, 40-46.
Open this publication in new window or tab >>Calculating fusion neutron energy spectra from arbitrary reactant distributions
2016 (English)In: Computer Physics Communications, ISSN 0010-4655, E-ISSN 1879-2944, Vol. 199, 40-46 p.Article in journal (Refereed) Published
Abstract [en]

The Directional Relativistic Spectrum Simulator (DRESS) code can perform Monte-Carlo calculations of reaction product spectra from arbitrary reactant distributions, using fully relativistic kinematics. The code is set up to calculate energy spectra from neutrons and alpha particles produced in the D(d, n)3He and T(d, n)4He fusion reactions, but any two-body reaction can be simulated by including the corresponding cross section. The code has been thoroughly tested. The kinematics calculations have been benchmarked against the kinematics module of the ROOT Data Analysis Framework. Calculated neutron energy spectra have been validated against tabulated fusion reactivities and against an exact analytical expression for the thermonuclear fusion neutron spectrum, with good agreement. The DRESS code will be used as the core of a detailed synthetic diagnostic framework for neutron measurements at the JET and MAST tokamaks.

Keyword
neutron energy spectra, relativistic kinematics
National Category
Fusion, Plasma and Space Physics Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-247991 (URN)10.1016/j.cpc.2015.10.010 (DOI)000367113200006 ()
Available from: 2015-03-25 Created: 2015-03-25 Last updated: 2017-12-04Bibliographically approved
Skiba, M., Ericsson, G., Hjalmarsson, A., Hellesen, C., Conroy, S., Andersson Sundén, E. & Eriksson, J. (2016). Kinematic Background Discrimination Methods Using a Fully Digital Data Acquisition System for TOFOR. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 838, 82-88.
Open this publication in new window or tab >>Kinematic Background Discrimination Methods Using a Fully Digital Data Acquisition System for TOFOR
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2016 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 838, 82-88 p.Article in journal (Other academic) Published
Abstract [en]

A fully digital, prototype data acquisition system upgrade for the TOFOR neutron time-of-flight neutron spectrometer at the JET experimental fusion reactor in Culham, England, has been constructed. This upgrade, TOFu (Time-of-Flight upgrade), enables digitization of associated time and energy deposition information from the TOFOR scintillator detectors, facilitating discrimination of spectral background due to unrelated neutron events based on kinematic considerations. In this publication, a kinematic background discrimination method is presented using synthetic data and validated with experimental results. It is found that an improvement in signal-to-background ratio of 500% in certain spectral regions is possible with the new DAQ system.

Keyword
Fusion; Time-of-flight spectrometry; JET; Neutron spectrometry; TOFOR; Data acquisition
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-304381 (URN)10.1016/j.nima.2016.09.030 (DOI)000386061200013 ()
Available from: 2016-10-04 Created: 2016-10-04 Last updated: 2017-11-30Bibliographically approved
Jansson, K., Gustavsson, C., Al-Adili, A., Hjalmarsson, A., Andersson Sundén, E., Prokofiev, A. V., . . . Pomp, S. (2015). Designing an upgrade of the Medley setup for light-ion production and fission cross-section measurements. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 794, 141-150.
Open this publication in new window or tab >>Designing an upgrade of the Medley setup for light-ion production and fission cross-section measurements
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2015 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 794, 141-150 p.Article in journal (Refereed) Published
Abstract [en]

Abstract Measurements of neutron-induced fission cross-sections and light-ion production are planned in the energy range 1-40 MeV at the upcoming Neutrons For Science (NFS) facility. In order to prepare our detector setup for the neutron beam with continuous energy spectrum, a simulation software was written using the Geant4 toolkit for both measurement situations. The neutron energy range around 20 MeV is troublesome when it comes to the cross-sections used by Geant4 since data-driven cross-sections are only available below 20 MeV but not above, where they are based on semi-empirical models. Several customisations were made to the standard classes in Geant4 in order to produce consistent results over the whole simulated energy range. Expected uncertainties are reported for both types of measurements. The simulations have shown that a simultaneous precision measurement of the three standard cross-sections H(n,n), 235U(n,f) and 238U(n,f) relative to each other is feasible using a triple layered target. As high resolution timing detectors for fission fragments we plan to use Parallel Plate Avalanche Counters (PPACs). The simulation results have put some restrictions on the design of these detectors as well as on the target design. This study suggests a fissile target no thicker than 2 µm (1.7 mg/cm2) and a PPAC foil thickness preferably less than 1 µm . We also comment on the usability of Geant4 for simulation studies of neutron reactions in this energy range.

Keyword
Neutron-induced fission, Light-ion production, Geant4, Standard cross-section, PPAC
National Category
Accelerator Physics and Instrumentation
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-255210 (URN)10.1016/j.nima.2015.05.001 (DOI)000356356100019 ()
Funder
Swedish Research Council
Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2017-12-04Bibliographically approved
Andersson, P., Bjelkenstedt, T., Andersson Sundén, E., Sjöstrand, H. & Jacobsson, S. (2015). Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops. In: : . Paper presented at 10th World Conference on Neutron Radiography (WCNR-10) Grindelwald, Switzerland October 5–10, 2014 (pp. 202-209). .
Open this publication in new window or tab >>Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops
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2015 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Detailed knowledge of the lateral distribution of steam (void) and water in a nuclear fuel assembly is of great value for nuclear reactor operators and fuel manufacturers, with consequences for both reactor safety and economy of operation. Therefore, nuclear relevant two-phase flows are being studied at dedicated thermal-hydraulic test loop, using twophase flow systems ranging from simplified geometries such as heated circular pipes to full scale mock-ups of nuclear fuel assemblies. Neutron tomography (NT) has been suggested for assessment of the lateral distribution of steam and water in such test loops, motivated by a good ability of neutrons to penetrate the metallic structures of metal pipes and nuclear fuel rod mock-ups, as compared to e. g. conventional X-rays, while the liquid water simultaneously gives comparatively good contrast. However, these stationary test loops require the measurement setup to be mobile, which is often not the case for NT setups. Here, it is acknowledged that fast neutrons of 14 MeV from mobile neutron generators constitute a viable option for a mobile NT system. We present details of the development of neutron tomography for this purpose at the division of Applied Nuclear Physics at Uppsala University. Our concept contains a portable neutron generator, exploiting the fusion reaction of deuterium and tritium, and a detector with plastic scintillator elements designed to achieve adequate spatial and energy resolution, all mounted in a light-weight frame without collimators or bulky moderation to allow for a mobile instrument that can be moved about the stationary thermal hydraulic test sections. The detector system stores event-to-event pulse-height information to allow for discrimination based on the energy deposition in the scintillator elements. Experimental results from the tomographic assessment of axially symmetric test objects are shown, as well as simulation results from a scaled up version of the instrument for nonsymmetrical objects in quarter fuel-bundle size objects. In conclusion, the application of tomography on inch-wide vertical pipes has been experimentally demonstrated and simulation results indicate that tomography of the void distribution in nonsymmetrical vertical flows in quarter BWR fuel bundles is also feasible.

Series
Physics Procedia, ISSN 1875-3892 ; 69
Keyword
Void distribution measurement; fast neutrons; neutron generator
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-262264 (URN)10.1016/j.phpro.2015.07.029 (DOI)000380606800029 ()
Conference
10th World Conference on Neutron Radiography (WCNR-10) Grindelwald, Switzerland October 5–10, 2014
Available from: 2015-09-11 Created: 2015-09-11 Last updated: 2017-05-05Bibliographically approved
Romanelli, F., Abhangi, M., Abreu, P., Aftanas, M., Afzal, M., Aggarwal, K. M., . . . Zychor, I. (2015). Overview of the JET results. Paper presented at 25th Fusion Energy Conference (FEC), OCT 13-18, 2014, Govt Russian Federat, St Petersburg, RUSSIA. Nuclear Fusion, 55(10), Article ID 104001.
Open this publication in new window or tab >>Overview of the JET results
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2015 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 55, no 10, 104001Article in journal, Meeting abstract (Refereed) Published
Abstract [en]

Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in confinement and pedestal behaviour before and after the ITER-like wall installation have been better characterized towards the development of high fusion yield scenarios in DT. Post-mortem analyses of the plasma-facing components have confirmed the previously reported low fuel retention obtained by gas balance and shown that the pattern of deposition within the divertor has changed significantly with respect to the JET carbon wall campaigns due to the absence of thermally activated chemical erosion of beryllium in contrast to carbon. Transport to remote areas is almost absent and two orders of magnitude less material is found in the divertor.

Keyword
JET, tokamaks, magnetic confinement
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-309696 (URN)10.1088/0029-5515/55/10/104001 (DOI)000363762900002 ()
Conference
25th Fusion Energy Conference (FEC), OCT 13-18, 2014, Govt Russian Federat, St Petersburg, RUSSIA
Available from: 2016-12-07 Created: 2016-12-07 Last updated: 2017-11-29Bibliographically approved
Binda, F., Ericsson, G., Eriksson, J., Hellesen, C., Conroy, S. & Sundén, E. A. (2014). Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET. Review of Scientific Instruments, 85(11), 11E123.
Open this publication in new window or tab >>Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET
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2014 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 85, no 11, 11E123- p.Article in journal (Refereed) Published
Abstract [en]

In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-240136 (URN)10.1063/1.4895565 (DOI)000345646000143 ()25430302 (PubMedID)
Available from: 2015-01-07 Created: 2015-01-05 Last updated: 2017-12-05
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