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Rakopoulos, V., Lantz, M., Solders, A., Al-Adili, A., Mattera, A., Canete, L., . . . Pomp, S. (2018). First isomeric yield ratio measurements by direct ion counting and implications for the angular momentum of the primary fission fragments. Physical Review C: Covering Nuclear Physics, 98(2), Article ID 024612.
Open this publication in new window or tab >>First isomeric yield ratio measurements by direct ion counting and implications for the angular momentum of the primary fission fragments
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2018 (English)In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 98, no 2, article id 024612Article in journal (Refereed) Published
Abstract [en]

We report the first experimental determination of independent isomeric yield ratios using direct ion counting with a Penning trap, which offered such a high resolution in mass that isomeric states could be separated. The measurements were performed at the Ion Guide Isotope Separator On-Line (IGISOL) facility at the University of Jyvaskyla. The isomer production ratios of Ge-81, Y-96,Y-97 Sn-128(,1)30, and Sb-129 in the 25-MeV proton-induced fission of U-na(t) and Th-232 were studied. Three isomeric pairs (Ge-81, Y-96, and Sb-129) were measured for the first time for the U-na(t)(p, f) reaction, while all the reported yield ratios for the Th-232(p, f) reaction were determined for the first time. The comparison of the experimentally determined isomeric yield ratios with data available in the literature shows a reasonable agreement, except for the case of Sn-130 for unspecified reasons. The obtained results were also compared with the GEF model, where good agreement can be noticed in most cases for both reactions. Serious discrepancies can only be observed for the cases of Y-96(,)97 for both reactions. Moreover, based on the isomeric yield ratios, the root-mean-square angular momenta (J(r)(ms)) of the fission fragments after scission were estimated using the TALYS code. The experimentally determined isomeric yield ratios, and consequently the deduced J(rms), for Sn-130 are significantly lower compared to Sn-128 for both fissioning systems. This can be attributed to the more spherical shape of the fragments that contribute to the formation of Sn-130, due to their proximity to the N = 82 shell closure. The values of J(rms) for Sb-129 are higher than Sn-128 for both reactions, despite the same neutron number of both nuclides (N = 78), indicating the odd-Z effect where fission fragments with odd-Z number tend to bear larger angular momentum than even-Z fragments. The isomer production ratio for the isotopes of Sn is more enhanced in the U-na(t)(p, f) reaction than in Th-232(p, f). The opposite is observed for Y-96 and Y-97. These discrepancies might be associated to different scission shapes of the fragments for the two fission reactions, indicating the impact that the different fission modes can have on the isomeric yield ratios.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2018
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-362692 (URN)10.1103/PhysRevC.98.024612 (DOI)000441464600003 ()
Funder
EU, FP7, Seventh Framework Programme, 605203Swedish Radiation Safety AuthoritySwedish Nuclear Fuel and Waste Management Company, SKBAcademy of Finland, 275389 284516 312544 295207
Available from: 2018-10-18 Created: 2018-10-18 Last updated: 2018-11-06Bibliographically approved
Pomp, S., Mattera, A., Rakopoulos, V., Al-Adili, A., Lantz, M., Solders, A., . . . Rinta-Antila, S. (2018). Measurement of fission yields and isomeric yield ratios at IGISOL. In: Hambsch, FJ Carjan, N Rusko, I (Ed.), Scientific Workshop on Nuclear Fission Dynamics And The Emission of Prompt Neutrons and Gamma Rays (Theory-4): . Paper presented at 4th Scientific Workshop on Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays (Theory), JUN 20-22, 2017, Varna, BULGARIA. , Article ID UNSP 00017.
Open this publication in new window or tab >>Measurement of fission yields and isomeric yield ratios at IGISOL
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2018 (English)In: Scientific Workshop on Nuclear Fission Dynamics And The Emission of Prompt Neutrons and Gamma Rays (Theory-4) / [ed] Hambsch, FJ Carjan, N Rusko, I, 2018, article id UNSP 00017Conference paper, Published paper (Refereed)
Abstract [en]

Data on fission yields and isomeric yield ratios (IYR) are tools to study the fission process, in particular the generation of angular momentum. We use the IGISOL facility with the Penning trap JYFLTRAP in Jyvaskyla, Finland, for such measurements on Th-232 and U-nat targets. Previously published fission yield data from IGISOL concern the Th-232(p,f) and U-238(p,f) reactions at 25 and 50 MeV. Recently, a neutron source, using the Be(p,n) reaction, has been developed, installed and tested. We summarize the results for (p,f) focusing on the first measurement of IYR by direct ion counting. We also present first results for IYR and relative yields for Sn and Sb isotopes in the 128-133 mass range from U-nat(n,f) based on gamma-spectrometry. We find a staggering behaviour in the cumulative yields for Sn and a shift in the independent fission yields for Sb as compared to current evaluations. Plans for the future experimental program on fission yields and IYR measurements are discussed.

Series
EPJ Web of Conferences, ISSN 2100-014X ; 169
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-361441 (URN)10.1051/epjconf/201816900017 (DOI)000433153800016 ()978-2-7598-9031-6 (ISBN)
Conference
4th Scientific Workshop on Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays (Theory), JUN 20-22, 2017, Varna, BULGARIA
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10Bibliographically approved
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: 2018-11-06Bibliographically approved
Al-Adili, A., Jansson, K., Tarrio, D., Hambsch, F.-J., Gook, A., Oberstedt, S., . . . Pomp, S. (2018). Studying fission neutrons with 2E-2v and 2E. In: Hambsch, FJ Carjan, N Rusko, I (Ed.), SCIENTIFIC WORKSHOP ON NUCLEAR FISSION DYNAMICS AND THE EMISSION OF PROMPT NEUTRONS AND GAMMA RAYS (THEORY-4): . Paper presented at 4th Scientific Workshop on Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays (Theory), JUN 20-22, 2017, Varna, BULGARIA. , Article ID UNSP 00002.
Open this publication in new window or tab >>Studying fission neutrons with 2E-2v and 2E
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2018 (English)In: SCIENTIFIC WORKSHOP ON NUCLEAR FISSION DYNAMICS AND THE EMISSION OF PROMPT NEUTRONS AND GAMMA RAYS (THEORY-4) / [ed] Hambsch, FJ Carjan, N Rusko, I, 2018, article id UNSP 00002Conference paper, Published paper (Refereed)
Abstract [en]

This work aims at measuring prompt-fission neutrons at different excitation energies of the nucleus. Two independent techniques, the 2E-2v and the 2E techniques, are used to map the characteristics of the mass-dependent prompt fission neutron multiplicity, 7(A), when the excitation energy is increased. The VERDI 2E-2v spectrometer is being developed at JRC-GEEL. The Fission Fragment (FF) energies are measured using two arrays of 16 silicon (Si) detectors each. The FFs velocities are obtained by time-of-flight, measured between micro-channel plates (MCP) and Si detectors. With MCPs placed on both sides of the fission source, VERDI allows for independent timing measurements for both fragments. Cf-252(sf) was measured and the present results revealed particular features of the 2E-2v technique. Dedicated simulations were also performed using the GEF code to study important aspects of the 2E-2v technique. Our simulations show that prompt neutron emission has a non-negligible impact on the deduced fragment data and affects also the shape of 17(A). Geometrical constraints lead to a total-kinetic energy-dependent detection efficiency. The 2E technique utilizes an ionization chamber together with two liquid scintillator detectors. Two measurements have been performed, one of Cf-252(sf) and another one of thermal-neutron induced fission in U-235(n,f). Results from Cf-252(sf) are reported here.

Series
EPJ Web of Conferences, ISSN 2100-014X ; 169
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-361440 (URN)10.1051/epjconf/201816900002 (DOI)000433153800001 ()978-2-7598-9031-6 (ISBN)
Conference
4th Scientific Workshop on Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays (Theory), JUN 20-22, 2017, Varna, BULGARIA
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10Bibliographically 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: 2018-11-06Bibliographically 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
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4725-3083

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