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Mattera, A., Pomp, S., Lantz, M., Solders, A., Rakopoulos, V., Al-Adili, A., . . . Gorelov, D. (2018). Production of Sn and Sb isotopes in high-energy neutron induced fission of natU. European Physical Journal A, 54, Article ID 33.
Open this publication in new window or tab >>Production of Sn and Sb isotopes in high-energy neutron induced fission of natU
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2018 (English)In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 54, article id 33Article in journal (Refereed) Published
Abstract [en]

The first systematic measurement of neutron-induced fission yields has been performed at the upgraded IGISOL-4 facility at the University of Jyvaskyla, Finland. The fission products from high-energy neutron-induced fission of U-nat were stopped in a gas cell filled with helium buffer gas, and were online separated with a dipole magnet. The isobars, with masses in the range A = 128-133, were transported to a tape-implantation station and identified using gamma-spectroscopy. We report here the relative cumulative isotopic yields of tin (Z = 50) and the relative independent isotopic yields of antimony (Z = 51). Isomeric yield ratios were also obtained for five nuclides. The yields of tin show a staggered behaviour around A = 131, not observed in the ENDF/B-VII. 1 evaluation. The yields of antimony also contradict the trend from the evaluation, but are in agreement with a calculation performed using the GEF model that shows the yield increasing with mass in the range A = 128-133.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-328572 (URN)10.1140/epja/i2018-12462-1 (DOI)000428637900002 ()
Funder
EU, FP7, Seventh Framework Programme, 605203Swedish Radiation Safety AuthoritySwedish Nuclear Fuel and Waste Management Company, SKB
Available from: 2017-08-26 Created: 2017-08-26 Last updated: 2018-06-04Bibliographically approved
Mattera, A., Al-Adili, A., Lantz, M., Pomp, S., Rakopoulos, V. & Solders, A. (2017). A methodology for the intercomparison of nuclear fission codes using TALYS. 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, September 11-16, 2016, Bruges, Belgium.. Les Ulis: EDP Sciences, 146, Article ID 04047.
Open this publication in new window or tab >>A methodology for the intercomparison of nuclear fission codes using TALYS
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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 04047Conference paper, Published paper (Refereed)
Abstract [en]

Codes for the calculation of fission observables are frequently used to describe experimentally observed phenomena as well as provide predictions in cases where measurements are missing. Assumptions in the models, and tuning of parameters within the codes, often result in a good reproduction of experimental data. In this work we propose a methodology, coded in the newly developed program DELFIN (De-Excitation of FIssion fragmeNts), that can be used to compare some of the assumptions of the various models. Our code makes use of the fission fragments information after scission and processes them in an independent and consistent fashion to obtain measurable fission observables (such as ν(A) distributions and Isomeric Fission Yield ratios). All the available information from the models, such as fragments' excitation energies, spin distributions and yields are provided as input to DELFIN that uses the nuclear reaction code TALYS to handle the de-excitation of the fission fragments. In this way we decouple the fragments relaxation from the actual fission models. We report here the first results of a comparison carried out on the GEF, Point-by-Point and FREYA models for thermal fission of 235U and 239Pu and spontaneous fission of 252Cf.

Place, publisher, year, edition, pages
Les Ulis: EDP Sciences, 2017
Series
EPJ Web of Conferences, ISSN 2100-014X
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-317442 (URN)10.1051/epjconf/201714604047 (DOI)000426429500146 ()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 Nuclear Fuel and Waste Management Company, SKBSwedish Radiation Safety Authority
Available from: 2017-03-14 Created: 2017-03-14 Last updated: 2018-07-03Bibliographically approved
Mattera, A., Pomp, S., Lantz, M., Rakopoulos, V., Solders, A., Al-Adili, A., . . . Eronen, T. (2017). A neutron source for IGISOL-JYFLTRAP: Design and characterisation. European Physical Journal A, 53(173)
Open this publication in new window or tab >>A neutron source for IGISOL-JYFLTRAP: Design and characterisation
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2017 (English)In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 53, no 173Article in journal (Refereed) Published
Abstract [en]

A white neutron source based on the Be(p,nx) reaction for fission studies at the IGISOLJYFLTRAP facility has been designed and tested. 30 MeV protons impinge on a 5mm thick water-cooled beryllium disc. The source was designed to produce at least 1012 fast neutrons/s on a secondary fission target, in order to reach competitive production rates of fission products far from the valley of stability.

The Monte Carlo codes MCNPX and FLUKA were used in the design phase to simulate the neutron energy spectra. Two experiments to characterise the neutron field were performed: the first was carried out at The Svedberg Laboratory in Uppsala (SE), using an Extended-Range Bonner Sphere Spectrometer and a liquid scintillator which used the time-of-flight (TOF) method to determine the energy of the neutrons; the second employed Thin-Film Breakdown Counters for the measurement of the TOF, and activation foils, at the IGISOL facility in Jyväskylä (FI). Design considerations and the results of the two characterisation measurements are presented, providing benchmarks for the simulations.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-328569 (URN)10.1140/epja/i2017-12362-x (DOI)000408661200001 ()
Funder
Swedish Radiation Safety AuthoritySwedish Nuclear Fuel and Waste Management Company, SKB
Available from: 2017-08-26 Created: 2017-08-26 Last updated: 2017-12-01Bibliographically approved
Rakopoulos, V., Lantz, M., Al-Adili, A., Gorelov, D., Jokinen, A., Kolhinen, V., . . . Pomp, S. (2017). Measurements of isomeric yield ratios of fission products from proton- induced fission on natU and 232Th via direct ion counting. 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, 11-16 september 2016, Bruges, Belgium. Les Ulis: EDP Sciences, 146, Article ID 04054.
Open this publication in new window or tab >>Measurements of isomeric yield ratios of fission products from proton- induced fission on natU and 232Th via direct ion counting
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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 04054Conference paper, Published paper (Refereed)
Abstract [en]

Independent isomeric yield ratios (IYR) of 81Ge, 96Y, 97Y, 97Nb, 128Sn and 130Sn have been determined in the 25 MeV proton-induced fission of natU and 232Th. The measurements were performed at the Ion Guide Isotope Separator On-Line (IGISOL) facility at the University of Jyväskylä. A direct ion counting measurement of the isomeric fission yield ratios was accomplished for the first time, registering the fission products in less than a second after their production. In addition, the IYRs of natU were measured by means of γ-spectroscopy in order to verify the consistency of the recently upgraded experimental setup. From the obtained results, indications of a dependence of the production rate on the fissioning system can be noticed. These data were compared with data available in the literature, whenever possible. Using the TALYS code and the experimentally obtained IYRs, we also deduced the average angular momentum of the fission fragments after scission.

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-319348 (URN)10.1051/epjconf/201714604054 (DOI)000426429500153 ()978-2-7598-9020-0 (ISBN)
Conference
ND 2016: International Conference on Nuclear Data for Science and Technology, 11-16 september 2016, Bruges, Belgium
Funder
Swedish Radiation Safety AuthoritySwedish Nuclear Fuel and Waste Management Company, SKB
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2018-07-03Bibliographically 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
Solders, A., Al-Adili, A., Gorelov, D., Jansson, K., Jokinen, A., Kolhinen, V., . . . Simutkin, V. (2017). Simulations of the stopping efficiencies of fission ion guides. 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, September 11-16, 2016, Bruges, Belgium.. Les Ulis: EDP Sciences, 146, Article ID 03025.
Open this publication in new window or tab >>Simulations of the stopping efficiencies of fission ion guides
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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 03025Conference paper, Published paper (Refereed)
Abstract [en]

With the Ion Guide Isotope Separator On-Line (IGISOL) facility, located at the University of Jyväskylä, products of nuclear reactions are separated by mass. The high resolving power of the JYFLTRAP Penning trap, with full separation of individual nuclides, capacitates the study of nuclides far from the line of stability. For the production of neutron-rich medium-heavy nuclides, fissioning of actinides is a feasible reaction. This can be achieved with protons from an in-house accelerator or, alternatively, with neutrons through the addition of a newly developed Be(p,xn)-converter. The hereby-obtained fission products are used in nuclear data measurements, for example fission yields, nuclear masses, Q-values and decay spectroscopy. Prior to separation, the ionized reaction products are stopped in a helium-filled gas cell, referred to as the ion-guide. In this work we present simulations of the stopping of fission products in an ion guide developed for neutron-induced fission. The production and extraction rates are evaluated and compared against experimental values.

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-319252 (URN)10.1051/epjconf/201714603025 (DOI)000426429500092 ()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 AuthoritySwedish Nuclear Fuel and Waste Management Company, SKB
Available from: 2017-04-02 Created: 2017-04-02 Last updated: 2018-07-03Bibliographically approved
Al-Adili, A., Tarrío, D., Hambsch, F.-J. -., Gook, A., Jansson, K., Solders, A., . . . Pomp, S. (2016). Analysis of prompt fission neutrons in U-235(nth,f) and fission fragment distributions for the thermal neutron induced fission of U-234. In: CNR*15 - 5th International Workshop On Compound-Nuclear Reactions And Related Topics: . Paper presented at 5th International Workshop on Compound-Nuclear Reactions and Related Topics (CNR), OCT 19-23, 2015, Tokyo, JAPAN. , Article ID 01007.
Open this publication in new window or tab >>Analysis of prompt fission neutrons in U-235(nth,f) and fission fragment distributions for the thermal neutron induced fission of U-234
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2016 (English)In: CNR*15 - 5th International Workshop On Compound-Nuclear Reactions And Related Topics, 2016, article id 01007Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents the ongoing analysis of two fission experiments. Both projects are part of the collaboration between the nuclear reactions group at Uppsala and the JRC-IRMM. The first experiment deals with the prompt fission neutron multiplicity in the thermal neutron induced fission of U-235(n,f). The second, on the fission fragment properties in the thermal fission of U-234(n,f). The prompt fission neutron multiplicity has been measured at the JRC-IRMM using two liquid scintillators in coincidence with an ionization chamber. The first experimental campaign focused on U-235(nth,f) whereas a second experimental campaign is foreseen later for the same reaction at 5.5 MeV. The goal is to investigate how the so-called saw-tooth shape changes as a function of fragment mass and excitation energy. Some harsh experimental conditions were experienced due to the large radiation background. The solution to this will be discussed along with preliminary results. In addition, the analysis of thermal neutron induced fission of U-234(n,f) will be discussed. Currently analysis of data is ongoing, originally taken at the ILL reactor. The experiment is of particular interest since no measurement exist of the mass and energy distributions for this system at thermal energies. One main problem encountered during analysis was the huge background of U-235(nth, f). Despite the negligible isotopic traces in the sample, the cross section difference is enormous. Solution to this parasitic background will be highlighted.

Series
EPJ Web of Conferences, ISSN 2100-014X ; 122
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-314830 (URN)10.1051/epjconf/201612201007 (DOI)000389877200007 ()
Conference
5th International Workshop on Compound-Nuclear Reactions and Related Topics (CNR), OCT 19-23, 2015, Tokyo, JAPAN
Available from: 2017-02-07 Created: 2017-02-06 Last updated: 2017-02-07Bibliographically approved
Mattera, A., Al-Adili, A., Lantz, M., Pomp, S., Solders, A. & Rakopoulos, V. (2016). Comparing Nuclear Fission Codes: GEF as standalone code vs GEF+TALYS. In: Fission Product Yields Data. Current status and perspectives: Summary report of an IAEA Technical Meeting. Paper presented at IAEA Technical Meeting on Fission Product Yields Data. IAEA Headquarters, Vienna: International Atomic Energy Agency
Open this publication in new window or tab >>Comparing Nuclear Fission Codes: GEF as standalone code vs GEF+TALYS
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2016 (English)In: Fission Product Yields Data. Current status and perspectives: Summary report of an IAEA Technical Meeting, IAEA Headquarters, Vienna: International Atomic Energy Agency, 2016Conference paper, Oral presentation with published abstract (Other academic)
Place, publisher, year, edition, pages
IAEA Headquarters, Vienna: International Atomic Energy Agency, 2016
Keywords
Fission, Fission Products, Fission Yields
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-313825 (URN)
Conference
IAEA Technical Meeting on Fission Product Yields Data
Available from: 2017-01-24 Created: 2017-01-24 Last updated: 2017-01-24Bibliographically approved
Gorelov, D., Penttilä, H., Al-Adili, A., Eronen, T., Hakala, J., Jokinen, A., . . . Äystö, J. (2016). Developments for neutron-induced fission at IGISOL-4. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Open this publication in new window or tab >>Developments for neutron-induced fission at IGISOL-4
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2016 (English)In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584Article in journal (Refereed) Published
Abstract [en]

Abstract At the IGISOL-4 facility, neutron-rich, medium mass nuclei have usually been produced via charged particle-induced fission of natural uranium and thorium. Neutron-induced fission is expected to have a higher production cross section of the most neutron-rich species. Development of a neutron source along with a new ion guide continues to be one of the major goals since the commissioning of IGISOL-4. Neutron intensities at different angles from a beryllium neutron source have been measured in an on-line experiment with a 30 MeV proton beam. Recently, the new ion guide coupled to the neutron source has been tested as well. Details of the neutron source and ion guide design together with preliminary results from the first neutron-induced fission experiment at IGISOL-4 are presented in this report.

Keywords
Isotope production, Neutron-induced fission, Target and ion source techniques, Low-energy separators, Ion guide
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-291551 (URN)10.1016/j.nimb.2016.02.049 (DOI)
Available from: 2016-05-03 Created: 2016-05-03 Last updated: 2017-11-30
Lantz, M., Al-Adili, A., Gorelov, D., Jokinen, A., Kolhinen, V. S., Mattera, A., . . . Solders, A. (2016). Fission yield measurements at IGISOL. In: Kawano, T; Chiba, S; Paris, MW; Talou, P (Ed.), CNR*15 - 5th International Workshop On Compound-Nuclear Reactions And Related Topics: . Paper presented at 5th International Workshop on Compound-Nuclear Reactions and Related Topics (CNR), OCT 19-23, 2015, Tokyo, JAPAN. , Article ID 01008.
Open this publication in new window or tab >>Fission yield measurements at IGISOL
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2016 (English)In: CNR*15 - 5th International Workshop On Compound-Nuclear Reactions And Related Topics / [ed] Kawano, T; Chiba, S; Paris, MW; Talou, P, 2016, article id 01008Conference paper, Published paper (Refereed)
Abstract [en]

The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutron-induced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyvaskyla, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

Series
EPJ Web of Conferences, ISSN 2100-014X ; 122
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-314832 (URN)10.1051/epjconf/201612201008 (DOI)000389877200008 ()
Conference
5th International Workshop on Compound-Nuclear Reactions and Related Topics (CNR), OCT 19-23, 2015, Tokyo, JAPAN
Available from: 2017-02-07 Created: 2017-02-06 Last updated: 2017-02-07Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4725-3083

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