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Andersson Sundén, Erik
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Publications (10 of 59) Show all publications
Jansson, K., Al-Adili, A., Andersson Sundén, E., Göök, A., Stephan, O. & Pomp, S. (2018). The impact of neutron emission on correlated fission data from the 2E-2v method. European Physical Journal A, 54, Article ID 114.
Open this publication in new window or tab >>The impact of neutron emission on correlated fission data from the 2E-2v method
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2018 (English)In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 54, article id 114Article in journal (Refereed) Published
Abstract [en]

The double-energy double-velocity (2E-2v) method allows assessing fission-fragment mass yields prior to and after prompt neutron emission with high resolution. It is, therefore, considered as a complementary technique to assess average prompt neutron multiplicity as a function of fragment properties. We have studied the intrinsic features of the 2E-2v method by means of event-wise generated fission-fragment data and found short-comings in the method itself as well as in some common practices of application. We find that the 2E-2v method leads to large deviations in the correlation between the prompt neutron multiplicity and pre-neutron mass, which deforms and exaggerates the so-called “sawtooth” shape of nubar(A). We have identified the treatment of prompt neutron emission from the fragments as the origin of the problem. The intrinsic nature of this deficiency risks to render 2E-2v experiments less interesting. We suggest a method to correct 2E-2v data that can even be applied on existing measurements.

Keywords
fission, 2E-2v, neutron
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-355518 (URN)10.1140/epja/i2018-12544-0 (DOI)000437217400002 ()
Funder
EU, FP7, Seventh Framework Programme, 605203
Available from: 2018-06-30 Created: 2018-06-30 Last updated: 2018-09-13Bibliographically approved
Binda, F., Ericsson, G., Conroy, S. & Andersson Sundén, E. (2017). Calculation of the profile-dependent neutron backscatter matrix for the JET neutron camera system. Paper presented at 29th Symposium on Fusion Technology (SOFT), SEP 05-09, 2016, Prague, CZECH REPUBLIC. Fusion engineering and design, 123, 865-868
Open this publication in new window or tab >>Calculation of the profile-dependent neutron backscatter matrix for the JET neutron camera system
2017 (English)In: Fusion engineering and design, ISSN 0920-3796, E-ISSN 1873-7196, Vol. 123, p. 865-868Article in journal (Refereed) Published
Abstract [en]

We investigated the dependence of the backscatter component of the neutron spectrum on the emissivity profile. We did so for the JET neutron camera system, by calculating a profile-dependent backscatter matrix for each of the 19 camera channels using a MCNP model of the JET tokamak. We found that, when using a low minimum energy for the summation of the counts in the neutron pulse height spectrum, the backscatter contribution can depend significantly on the emissivity profile. The maximum variation in the backscatter level was 24% (8.0% when compared to the total emission). This effect needs to be considered when a correction for the backscatter contribution is applied to the measured profile.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2017
Keywords
Neutron, Profile monitor, Backscatter, mcnp
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-341822 (URN)10.1016/j.fusengdes.2017.03.124 (DOI)000418992000181 ()
Conference
29th Symposium on Fusion Technology (SOFT), SEP 05-09, 2016, Prague, CZECH REPUBLIC
Available from: 2018-02-15 Created: 2018-02-15 Last updated: 2018-03-13Bibliographically approved
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. In: Plompen, A.; Hambsch, FJ.; Schillebeeckx, P.; Mondelaers, W.; Heyse, J.; Kopecky, S.; Siegler, P.; Oberstedt, S. (Ed.), ND 2016: International Conference On Nuclear Data For Science And Technology. Paper presented at ND 2016: International Conference on Nuclear Data for Science and Technology, Sep 11-16, 2016, Bruges, Belgium.. Les Ulis: EDP Sciences, 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: ND 2016: International Conference On Nuclear Data For Science And Technology / [ed] Plompen, A.; Hambsch, FJ.; Schillebeeckx, P.; Mondelaers, W.; Heyse, J.; Kopecky, S.; Siegler, P.; Oberstedt, S., Les Ulis: EDP Sciences, 2017, Vol. 146, article id 03026Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
Les Ulis: EDP Sciences, 2017
Series
EPJ Web of Conferences, ISSN 2100-014X
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-338734 (URN)10.1051/epjconf/201714603026 (DOI)000426429500093 ()978-2-7598-9020-0 (ISBN)
Conference
ND 2016: International Conference on Nuclear Data for Science and Technology, Sep 11-16, 2016, Bruges, Belgium.
Funder
Swedish Research CouncilEU, FP7, Seventh Framework Programme, 605203
Available from: 2018-01-12 Created: 2018-01-12 Last updated: 2018-07-03Bibliographically 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, article id 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.

Keywords
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: 2018-08-17Bibliographically approved
Hellesen, C., Andersson Sundén, E., Conroy, S., Dzysiuk, N., Ericsson, G., Hjalmarsson, A., . . . Marcinkevicius, B. (2017). Conceptual design of a BackTOF neutron spectrometer for fuel ion ratio measurements at ITER. Nuclear Fusion, 57(6), Article ID 066021.
Open this publication in new window or tab >>Conceptual design of a BackTOF neutron spectrometer for fuel ion ratio measurements at ITER
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2017 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 57, no 6, article id 066021Article in journal (Refereed) Published
Abstract [en]

In this paper we present a conceptual design of a back scattering neutron time of flight spectrometer (BackTOF) for use at ITER. The proposed BackTOF design aims at fulfilling the requirements set on a neutron spectrometer system to be used for inferring the core fuel ion ratio in a DT plasma. Specifically we have investigated the requirements on the size, energy resolution, count rate capability, efficiency and signal to background ratio. These requirements are a compact size that fits in roughly 1 m3, an energy resolution of 4% or better, a count rate capability of at least 100 kHz, an efficiency of at least 10−5 and a signal to background ratio of 1000 or better.

Using a Monte Carlo model of the BackTOF spectrometer we find that the proposed BackTOF design is compact enough to be installed at ITER while being capable of achieving a resolution of about 4% FWHM with a count rate capability of 300 kHz and an efficiency at 1.25 10−3. This is sufficient for achieving the requirements on the fuel ion ratio at ITER. We also demonstrate how data acquisition systems capable of providing both timing and energy information can be used to effectively discriminate random background at high count rates.

Keywords
neutron spectroscopy, time of flight, burning plasma, fuel ion ratio
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-348803 (URN)10.1088/1741-4326/aa6937 (DOI)000425870000001 ()
Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2018-05-04Bibliographically approved
Kazakov, Y. O. O., Possnert, G., Sjöstrand, H., Skiba, M., Weiszflog, M., Andersson Sundén, E., . . . Kazantzidis, V. (2017). Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating. Nature Physics, 13(10), 973-978
Open this publication in new window or tab >>Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating
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2017 (English)In: Nature Physics, ISSN 1745-2473, E-ISSN 1745-2481, Vol. 13, no 10, p. 973-978Article in journal (Refereed) Published
Abstract [en]

We describe a new technique for the efficient generation of high-energy ions with electromagnetic ion cyclotron waves in multi-ion plasmas. The discussed three-ion scenarios are especially suited for strong wave absorption by a very low number of resonant ions. To observe this effect, the plasma composition has to be properly adjusted, as prescribed by theory. We demonstrate the potential of the method on the world-largest plasma magnetic confinement device, JET (Joint European Torus, Culham, UK), and the high-magnetic-field tokamak Alcator C-Mod (Cambridge, USA). The obtained results demonstrate efficient acceleration of He-3 ions to high energies in dedicated hydrogendeuterium mixtures. Simultaneously, effective plasma heating is observed, as a result of the slowing-down of the fast He-3 ions. The developed technique is not only limited to laboratory plasmas, but can also be applied to explain observations of energetic ions in space-plasma environments, in particular, He-3-rich solar flares.

National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-359272 (URN)10.1038/NPHYS4167 (DOI)000412181200018 ()
Note

For a complete list of authors see http://dx.doi.org/10.1038/NPHYS4167

Available from: 2018-09-05 Created: 2018-09-05 Last updated: 2018-09-05Bibliographically 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, p. 222-229Article 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.

Keywords
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: 2018-04-23Bibliographically approved
Al-Adili, A., Tarrío, D., Hambsch, F.-J., Göök, A., Jansson, K., Solders, A., . . . Pomp, S. (2017). Neutron-multiplicity experiments for enhanced fission modelling. In: Plompen, A.; Hambsch, FJ.; Schillebeeckx, P.; Mondelaers, W.; Heyse, J.; Kopecky, S.; Siegler, P.; Oberstedt, S. (Ed.), EPJ Web of Conferences: . Paper presented at ND 2016: International Conference on Nuclear Data for Science and Technology, September 11-16, 2016, Bruges, Belgium.. , 146, Article ID 04056.
Open this publication in new window or tab >>Neutron-multiplicity experiments for enhanced fission modelling
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2017 (English)In: EPJ Web of Conferences / [ed] Plompen, A.; Hambsch, FJ.; Schillebeeckx, P.; Mondelaers, W.; Heyse, J.; Kopecky, S.; Siegler, P.; Oberstedt, S., 2017, Vol. 146, article id 04056Conference paper, Published paper (Refereed)
Abstract [en]

The nuclear de-excitation process of fission fragments (FF) provides fundamental information for the understanding of nuclear fission and nuclear structure in neutron-rich isotopes. The variation of the prompt-neutron multiplicity, ν(A), as a function of the incident neutron energy (En) is one of many open questions. It leads to significantly different treatments in various fission models and implies that experimental data are analyzed based on contradicting assumptions. One critical question is whether the additional excitation energy (Eexc) is manifested through an increase of ν(A) for all fragments or for the heavy ones only. A systematic investigation of ν(A) as a function of En has been initiated. Correlations between prompt-fission neutrons and fission fragments are obtained by using liquid scintillators in conjunction with a Frisch-grid ionization chamber. The proof-of-principle has been achieved on the reaction 235U(nth,f) at the Van De Graff (VdG) accelerator of the JRC-Geel using a fully digital data acquisition system. Neutrons from 252Cf(sf) were measured separately to quantify the neutron-scattering component due to surrounding shielding material and to determine the intrinsic detector efficiency. Prelimenary results on ν(A) and spectrum in correlation with FF properties are presented.

Series
EPJ Web of Conferences, ISSN 2100-014X
National Category
Subatomic Physics
Research subject
Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-339390 (URN)10.1051/epjconf/201714604056 (DOI)000426429500155 ()978-2-7598-9020-0 (ISBN)
Conference
ND 2016: International Conference on Nuclear Data for Science and Technology, September 11-16, 2016, Bruges, Belgium.
Funder
Swedish Radiation Safety Authority
Available from: 2018-01-18 Created: 2018-01-18 Last updated: 2018-07-03Bibliographically 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, article id 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.

Keywords
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: 2018-08-17Bibliographically approved
Litaudon, X., Abduallev, S., Abhangi, M., Abreu, P., Afzal, M., Aggarwal, K. M., . . . Zychor, I. (2017). Overview of the JET results in support to ITER. Nuclear Fusion, 57(10), Article ID 102001.
Open this publication in new window or tab >>Overview of the JET results in support to ITER
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2017 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 57, no 10, article id 102001Article in journal (Refereed) Published
Abstract [en]

The 2014-2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L-H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent measurements of fine-scale structures in the edge radial electric. Dimensionless scans of the core and pedestal confinement provide new information to elucidate the importance of the first wall material on the fusion performance. H-mode plasmas at ITER triangularity (H = 1 at beta(N) similar to 1.8 and n/n(GW) similar to 0.6) have been sustained at 2 MA during 5 s. The ITER neutronics codes have been validated on high performance experiments. Prospects for the coming D-T campaign and 14 MeV neutron calibration strategy are reviewed.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2017
Keywords
JET, plasma, fusion, ITER
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-340063 (URN)10.1088/1741-4326/aa5e28 (DOI)000416419100001 ()
Available from: 2018-01-25 Created: 2018-01-25 Last updated: 2018-04-23Bibliographically approved
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