| 1. |
- Diakaki, M., et al.
(författare)
-
Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN -€“ n_TOF
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
-
Konferensbidrag (refereegranskat)abstract
- The U-238 fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The U-238 fission cross section has been measured relative to the U-235 fission cross section at CERN - n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.
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| 2. |
- Paradela, C., et al.
(författare)
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High-accuracy determination of the 238U/235U fission cross section ratio up to ~1 GeV at n_TOF at CERN
- 2015
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 91, s. 024602-
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Tidskriftsartikel (refereegranskat)abstract
- The U238 to U235 fission cross section ratio has been determined at n_TOF up to ≈1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3–4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n_TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to ≈1 GeV.
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| 3. |
- Antonov, A. N., et al.
(författare)
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The electron-ion scattering experiment ELISe at the International Facility for Antiproton and Ion Research (FAIR)-A conceptual design study
- 2011
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087. ; 637:1, s. 60-76
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Tidskriftsartikel (refereegranskat)abstract
- The electron-ion scattering experiment ELISe is part of the installations envisaged at the new experimental storage ring at the International Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. It offers an unique opportunity to use electrons as probe in investigations of the structure of exotic nuclei. The conceptual design and the scientific challenges of ELISe are presented. (C) 2011 Elsevier B.V. All rights reserved.
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| 4. |
- Paradela, C., et al.
(författare)
-
High accuracy 235U(n,f) data in the resonance energy region
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
-
Konferensbidrag (refereegranskat)abstract
- The U-235 neutron-induced cross section is widely used as reference cross section for measuring other fission cross sections, but in the resonance region it is not considered as an IAEA standard because of the scarce experimental data covering the full region. In this work, we deal with a new analysis of the experimental data obtained with a detection setup based on parallel plate ionization chambers (PPACs) at the CERN n_TOF facility in the range from 1 eV to 10 keV. The relative cross section has been normalised to the IAEA value in the region between 7.8 and 11 eV, which is claimed as well-known. Comparison with the ENDF/B-VII evaluation and the IAEA reference file from 100 eV to 10 keV are provided.
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| 5. |
- Graña-González, A., et al.
(författare)
-
Quasi-free (p,2p) reactions in inverse kinematics for studying the fission yield dependence on temperature
- 2023
-
Ingår i: FAIR next generation scientists - 7th Edition Workshop : FAIRness2022 - FAIRness2022. - 1824-8039. ; 419
-
Konferensbidrag (refereegranskat)abstract
- Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it is a very complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom, as well as different quantum-mechanical phenomena. To improve on the existing data on nuclear fission, we produce fission reactions of heavy nuclei in inverse kinematics by using quasi-free (p,2p) scattering, which induce fission through particle-hole excitations that can range from few to ten's of MeV. The measurement of the four-momenta of the two outgoing protons allows to reconstruct the excitation energy of the fissioning compound nucleus and therefore to study the evolution of the fission yields with temperature. The realization of this kind of experiment requires a complex experimental setup, providing full isotopic identification of both fission fragments and an accurate measurement of the momenta of the two outgoing protons. This was realized recently at the GSI/FAIR facility and here some preliminary results are presented.
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| 6. |
- Audouin, L., et al.
(författare)
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Quantifying differences between computational results and measurements in the case of a large-scale well-confined fire scenario
- 2011
-
Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 1872-759X .- 0029-5493. ; 241:1, s. 18-31
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this work was to quantify comparisons between several computational results and measurements performed during a pool fire scenario in a well-confined compartment. This collaborative work was initiated under the framework of the OECD fire research program and involves the most frequently used fire models in the fire community, including field and zone models. The experimental scenario was conducted at the French Institut de Radioprotection et de Surete Nucleaire (IRSN) and deals with a full-scale liquid pool fire in a confined and mechanically ventilated compartment representative for nuclear plants. The practical use of different metric operators and their ability to report the capabilities of fire models are presented. The quantitative comparisons between measurements and numerical results obtained from "open" calculations concern six important quantities from a safety viewpoint: gas temperature, oxygen concentration, wall temperature, total heat flux, compartment pressure and ventilation flow rate during the whole fire duration. The results indicate that it is important to use more than one metric for the validation process in order to get information on the uncertainties associated with different aspects of fire safety. (C) 2010 Elsevier B.V. All rights reserved.
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| 7. |
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| 8. |
- Leal-Cidoncha, E., et al.
(författare)
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High accuracy 234U(n,f) cross section in the resonance energy region
- 2017
-
Ingår i: ND 2016. - Les Ulis : EDP Sciences. - 9782759890200
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Konferensbidrag (refereegranskat)abstract
- New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n_TOF data [1], has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n_TOF neutron flux.
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| 9. |
- Ledoux, X., et al.
(författare)
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The Neutrons for Science Facility at SPIRAL-2
- 2014
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Ingår i: Nuclear Data Sheets. - : Elsevier BV. - 0090-3752 .- 1095-9904. ; 119, s. 353-356
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Tidskriftsartikel (refereegranskat)abstract
- The Neutrons For Science (NFS) facility is a component of SPIRAL-2 laboratory under construction at Caen (France). SPIRAL-2 is dedicated to the production of high intensity Radioactive Ions Beams (RIB). It is based on a high-power linear accelerator (LINAG) to accelerate deuterons beams in order to produce neutrons by breakup reactions on a C converter. These neutrons will induce fission in U-238 for production of radioactive isotopes. Additionally to the RIB production, the proton and deuteron beams delivered by the accelerator will be used in the NFS facility. NFS is composed of a pulsed neutron beam and irradiation stations for cross-section measurements and material studies. The beams delivered by the LINAG will allow producing intense neutron beams in the 100 keV-40 MeV energy range with either a continuous or quasi-mono-energetic spectrum. At NFS available average fluxes will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV - 40 MeV range. NFS will be a very powerful tool for fundamental physics and application related research in support of the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. The facility and its characteristics are described, and several examples of the first potential experiments are presented.
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| 10. |
- Rodriguez-Sancheza, J. L., et al.
(författare)
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Comprehensive investigation of fission yields by using spallation- and (p,2p)induced fission reactions in inverse kinematics
- 2023
-
Ingår i: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - 2100-014X. ; 284
-
Konferensbidrag (refereegranskat)abstract
- In the last decades, measurements of spallation, fragmentation and Coulex induced fission reactions in inverse kinematics have provided valuable data to accurately investigate the fission dynamics and nuclear structure at large deformations of a large variety of stable and non -stable heavy nuclei. To go a step further, we propose now to induce fission by the use of quasi -free (p,2p) scattering reactions in inverse kinematics, which allows us to reconstruct the excitation energy of the compound fissioning system by using the four-momenta of the two outgoing protons. Therefore, this new approach might permit to correlate the excitation energy with the charge and mass distributions of the fission fragments and with the fission probabilities, given for the first time direct access to the simultaneous measurement of the fission yield dependence on temperature and fission barrier heights of exotic heavy nuclei, respectively. The first experiment based on this methodology was realized recently at the GM/FAIR facility and a detailed description of the experimental setup is given here.
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| 11. |
- Audouin, L., et al.
(författare)
-
High-precision measurement of isotopic fission yields of 236 U
- 2018
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 193
-
Konferensbidrag (refereegranskat)abstract
- We report on the second SOFIA experiment, dedicated to the fission yields of 236U∗, analog to 235U(n,f). The measurement is based on the inverse kinematics method, using a relativistic, secondary beam of 236U. Both fission fragments are identified in mass and charge in the SOFIA recoil spectrometer. The obtained isotopic yields are compared with existing spectroscopy measurements and the elemental yields are used to discuss the treatment of the even-odd effect with energy in nuclear data libraries.
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| 12. |
- Chatillon, A., et al.
(författare)
-
Accurate measurements of fission-fragment yields in U-234,U-235,U-236,U-238(gamma,f) with the SOFIA set-up
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759819706 ; 111
-
Konferensbidrag (refereegranskat)abstract
- SOFIA (Studies On Fission with Aladin) is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (gamma,f) electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in U-234,U-235,U-236,U-238(gamma,f) reactions.
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| 13. |
- Chatillon, A., et al.
(författare)
-
Evidence for a New Compact Symmetric Fission Mode in Light Thorium Isotopes
- 2020
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 124:20
-
Tidskriftsartikel (refereegranskat)abstract
- Taking benefit of the R3B/SOFIA setup to measure the mass and the nuclear charge of both fission fragments in coincidence with the total prompt-neutron multiplicity, the scission configurations are inferred along the thorium chain, from the asymmetric fission in the heavier isotopes to the symmetric fission in the neutron-deficient thorium. Against all expectations, the symmetric scission in the light thorium isotopes shows a compact configuration, which is in total contrast to what is known in the fission of the heavier thorium isotopes and heavier actinides. This new main symmetric scission mode is characterized by a significant drop in deformation energy of the fission fragments of about 19 MeV, compared to the well-known symmetric scission in the uranium-plutonium region.
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| 14. |
- Chatillon, A., et al.
(författare)
-
Experimental study of nuclear fission along the thorium isotopic chain: From asymmetric to symmetric fission
- 2019
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 99:5
-
Tidskriftsartikel (refereegranskat)abstract
- The inverse kinematics technique, applied to radioactive beams and combined to the Coulomb excitation method, is a powerful tool to study low-energy fission. A novel experimental setup was developed within the R3B/SOFIA (Reactions with Relativistic Radioactive Beams/Studies On FIssion with Aladin) collaboration to identify in mass and atomic numbers both fission fragments in coincidence. These new data provide elemental, isobaric, and isotonic yields for the fission along the thorium isotopic chain. Results are also compared to previous measurements using either the same reaction mechanism or thermal-neutron induced fission. This latter comparison permits to probe the influence of the excitation energy in the fission process.
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| 15. |
- Chatillon, A., et al.
(författare)
-
Fission-fragment yields measured in Coulomb-induced fission of U-234,U-235,U-236,U-238 and Np-237,Np-238 with the (RB)-B-3/SOFIA setup
- 2023
-
Ingår i: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - 2100-014X. ; 284
-
Konferensbidrag (refereegranskat)abstract
- Low energy fission of (234,235,236,238)u and Np-237,Np-381 radioactive beams, provided by the GSI/FRS facility, has been studied using the (RB)-B-3/SOFIA setup. The latter allows, on an event-by-event basis, to simultaneously identify, in terms of their mass and atomic numbers, the fissioning nucleus in coincidence with both fission fragments after prompt-neutron emission. This presentation reports on new results on elemental, isobaric and isotopic yields.
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| 16. |
- Grente, L., et al.
(författare)
-
The SOFIA experiment: Measurement of 236U fission fragment yields in inverse kinematics
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 122:01006
-
Konferensbidrag (refereegranskat)abstract
- The SOFIA (Studies On FIssion with Aladin) experiment aims at measuring fission-fragments isotopic yields with high accuracy using inverse kinematics at relativistic energies. This experimental technique allows to fully identify the fission fragments in nuclear charge and mass number, thus providing very accurate isotopic yields for low energy fission of a large variety of fissioning systems. This report focuses on the latest results obtained with this set-up concerning electromagnetic-induced fission of 236U.
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| 17. |
- Leal-Cidoncha, E., et al.
(författare)
-
Fission Fragment Angular Distribution measurements of 235U and 238U at CERN n_TOF facility
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
-
Konferensbidrag (refereegranskat)abstract
- Neutron-induced fission cross sections of U-238 and U-235 are used as standards in the fast neutron region up to 200 MeV. A high accuracy of the standards is relevant to experimentally determine other neutron reaction cross sections. Therefore, the detection efficiency should be corrected by using the angular distribution of the fission fragments (FFAD), which are barely known above 20 MeV. In addition, the angular distribution of the fragments produced in the fission of highly excited and deformed nuclei is an important observable to investigate the nuclear fission process. In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs) has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new U-235(n,f) and U-238(n,f) data in the extended energy range up to 200 MeV compared to the existing experimental data.
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| 18. |
- Martin, J. F., et al.
(författare)
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Fission-fragment yields and prompt-neutron multiplicity for Coulomb-induced fission of and
- 2021
-
Ingår i: Physical Review C. - 2469-9993 .- 2469-9985. ; 104:4
-
Tidskriftsartikel (refereegranskat)abstract
- Low-energy fission of and radioactive beams, provided by the Fragment Separator (FRS) of the GSI Helmholtzzentrum für Schwerionenforschung facility (GSI), has been studied using the Reactions with Relativistic Radioactive Beams / Studies on Fission with Aladin (R3B/SOFIA) setup. The latter allows us, on an event-by-event basis, to simultaneously identify, in terms of their mass and atomic numbers, the fissioning nucleus in coincidence with both fission fragments after prompt-neutron emission. This article reports new results on elemental, isotonic, isobaric, and isotopic yields. Moreover, the high accuracy of our data allowed us to study in detail proton even-odd staggering, from elemental yields; neutron excess, from isotopic yields; and total prompt-neutron multiplicity, from the difference of masses of the fissioning nucleus and fission fragments. These results are then compared to previous experimental data in order to probe how these fission observables change as function of the excitation energy and atomic and neutron numbers of the compound nucleus.
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| 19. |
- Martin, J. F., et al.
(författare)
-
Studies on fission with ALADIN Precise and simultaneous measurement of fission yields, total kinetic energy and total prompt neutron multiplicity at GSI
- 2015
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 51:12, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A novel technique for fission studies, based on the inverse kinematics approach, is presented. Following pioneering work in the nineties, the SOFIA Collaboration has designed and built an experimental set-up dedicated to the simultaneous measurement of isotopic yields, total kinetic energies and total prompt neutron multiplicities, by fully identifying both fission fragments in coincidence, for the very first time. This experiment, performed at GSI, permits to study the fission of a wide variety of fissioning systems, ranging from mercury to neptunium, possibly far from the valley of stability. A first experiment, performed in 2012, has provided a large array of unprecedented data regarding the nuclear fission process. An excerpt of the results is presented. With this solid starter, further improvements of the experimental set-up are considered, which are consistent with the expected developments at the GSI facility, in order to measure more fission observables in coincidence. The completeness reached in the SOFIA data, permits to scrutinize the correlations between the interesting features of fission, offering a very detailed insight in this still unraveled mechanism.
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| 20. |
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| 21. |
- Paradela, C., et al.
(författare)
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Isotopic production cross sections of residual nuclei in the spallation reaction Xe-136 (200A MeV) + p
- 2017
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 95:4
-
Tidskriftsartikel (refereegranskat)abstract
- The residual nuclei produced in the spallation reaction of Xe-136 nuclei at 200A MeV on protons have been studied by measuring the isotopic distributions for the elements from cadmium (Z = 48) to cesium (Z = 55) by using the fragment separator (FRS) spectrometer at GSI and the inverse kinematics technique. This is one of the few measurements performed at such a low projectile energy, close to the validity limit for intranuclear cascade models such as INCL or ISABEL. The experimental results have been compared to these intranuclear cascade codes coupled to the evaporation code ABLA. Both code combinations reproduce qualitatively the measured isotopic distributions; however, both underestimate the production of residues with mass numbers between 126 and 134. The measured cross sections are of interest for the planning of future radioactive beam or neutron source facilities.
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| 22. |
- Pellereau, E., et al.
(författare)
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Accurate isotopic fission yields of electromagnetically induced fission of U 238 measured in inverse kinematics at relativistic energies
- 2017
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 95:5, s. 054603-
-
Tidskriftsartikel (refereegranskat)abstract
- SOFIA (Studies On Fission with Aladin) is a novel experimental program, dedicated to accurate measurements of fission-fragment isotopic yields. The setup allows us to fully identify, in nuclear charge and mass, both fission fragments in coincidence for the whole fission-fragment range. It was installed at the GSI facility (Darmstadt), to benefit from the relativistic heavy-ion beams available there, and thus to use inverse kinematics. This paper reports on fission yields obtained in electromagnetically induced fission of U238.
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| 23. |
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| 24. |
- Praena, J., et al.
(författare)
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Preparation and characterization of 33S samples for 33S(n,alpha)30Si cross-section measurements at the n_TOF facility at CERN
- 2018
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 890, s. 142-147
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Tidskriftsartikel (refereegranskat)abstract
- Thin 33S samples for the study of the 33S(n,alpha)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.
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| 25. |
- Tarrío, Diego, et al.
(författare)
-
Fission Fragment Angular Distribution of Th-232(n,f) at the CERN n_TOF Facility
- 2014
-
Ingår i: Nuclear Data Sheets. - Univ Santiago de Compostela, Santiago De Compostela, Spain. [Leong, L. S.; Audouin, L.; Tassan-Got, L.; Lederer, C.] IPN, CNRS, IN2P3, Orsay, France. [Altstadt, S.; Langer, C.; Lederer, C.; Reifarth, R.; Schmidt, S.; Weigand, M.] Goethe Univ Frankfurt, D-60054 Frankfurt, Germany. [Andrzejewski, J.; Marganiec, J.; Perkowski, J.] Univ Lodz, PL-90131 Lodz, Poland. [Barbagallo, M.; Colonna, N.; Mastromarco, M.; Meaze, M.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, I-70126 Bari, Italy. [Becares, V.; Cano-Ott, D.; Garcia, A. R.; Gonzalez-Romero, E.; Martinez, T.; Mendoza, E.] CIEMAT, E-28040 Madrid, Spain. [Becvar, F.; Krticka, M.; Kroll, J.; Valenta, S.] Charles Univ Prague, Prague, Czech Republic. [Belloni, F.; Berthoumieux, E.; Bosnar, D.; Chiaveri, E.; Fraval, K.; Gunsing, F.] CEA Saclay, Irfu, F-91191 Gif Sur Yvette, France. [Berthoumieux, E.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Cerutti, F.; Chiaveri, E.; Chin, M.; Ferrari, A.; Guerrero, C.; Kadi, Y.; Losito, R.; Roman, F.; Rubbia, C.; Tsinganis, A.; Versaci, R.; Vlachoudis, V.] CERN, European Org Nucl Res, CH-1211 Geneva, Switzerland. [Billowes, J.; Ware, T.; Wright, T. J.] Univ Manchester, Manchester, Lancs, England. [Zugec, P.] Univ Zagreb, Fac Sci, Dept Phys, Zagreb 41000, Croatia. [Calvino, F.; Cortes, G.; Gomez-Hornillos, M. B.; Riego, A.] Univ Politecn Cataluna, Barcelona, Spain. [Carrapico, C.; Goncalves, I. F.; Sarmento, R.; Vaz, P.] Univ Tecn Lisboa, Inst Super Tecn, Inst Tecnol Nucl, P-1096 Lisbon, Portugal. [Cortes-Giraldo, M. A.; Praena, J.; Quesada, J. M.] Univ Seville, Seville, Spain. [Diakaki, M.; Karadimos, D.; Kokkoris, M.; Vlastou, R.] Natl Tech Univ Athens, GR-10682 Athens, Greece. [Domingo-Pardo, C.; Giubrone, G.; Tain, J. L.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46003 Valencia, Spain. [Dzysiuk, N.; Mastinu, P. F.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, Milan, Italy. [Eleftheriadis, C.; Manousos, A.] Aristotle Univ Thessaloniki, GR-54006 Thessaloniki, Greece. [Ganesan, S.; Gurusamy, P.] Bhabha Atom Res Ctr, Bombay 400085, Maharashtra, India. [Griesmayer, E.; Jericha, E.; Leeb, H.; Weiss, C.] Vienna Univ Technol, Inst Atom, Vienna, Austria. [Jenkins, D. G.; Vermeulen, M. J.] Univ York, York YO10 5DD, N Yorkshire, England. [Kaeppeler, F.] Karlsruhe Inst Technol, Inst Kernphys, D-76021 Karlsruhe, Germany. [Koehler, P.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Lederer, C.; Pavlik, A.; Wallner, A.] Univ Vienna, Fac Phys, A-1010 Vienna, Austria. [Massimi, C.; Mingrone, F.; Vannini, G.] Univ Bologna, Dipartimento Fis, I-40126 Bologna, Italy. [Massimi, C.; Mingrone, F.; Vannini, G.] Sez INFN Bologna, Bologna, Italy. [Mengoni, A.; Ventura, A.] Agenzia Nazl Nuove Tecnol, Eenergia & Sviluppo Econ Sostenibile ENEA, Bologna, Italy. [Milazzo, P. M.] Ist Nazl Fis Nucl, Trieste, Italy. [Mirea, M.; Roman, F.] Horia Hulubei Natl Inst Phys & Nucl Engn, IFIN HH, Bucharest, Romania. [Mondalaers, W.; Plompen, A.; Schillebeeckx, P.] European Commiss JRC, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. [Rauscher, T.] Univ Basel, Dept Phys & Astron, Basel, Switzerland. [Rubbia, C.] Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, Assergi, AQ, Italy. : Elsevier BV. - 0090-3752 .- 1095-9904. ; 119, s. 35-37
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Tidskriftsartikel (refereegranskat)abstract
- The angular distribution of fragments emitted in neutron-induced fission of Th-232 was measured in the white spectrum neutron beam at the n_TOF facility at CERN. A reaction chamber based on Parallel Plate Avalanche Counters (PPAC) was used, where the detectors and the targets have been tilted 45 degrees with respect to the neutron beam direction in order to cover the full angular range of the fission fragments. A GEANT4 simulation has been developed to study the setup efficiency. The data analysis and the preliminary results obtained for the Th-232(n,f) between fission threshold and 100 MeV are presented here.
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| 26. |
- Tarrío, Diego, et al.
(författare)
-
Measurement of the angular distribution of fission fragments using a PPAC assembly at CERN n_TOF
- 2014
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 743, s. 79-85
-
Tidskriftsartikel (refereegranskat)abstract
- A fission reaction chamber based on Parallel Plate Avalanche Counters (PPACs) was built for measuring angular distributions of fragments emitted in neutron-induced fission of actinides at the neutron beam available at the Neutron Time-Of-Flight (n_TOF) facility at CERN. The detectors and the samples were tilted 45 degrees with respect to the neutron beam direction to cover all the possible values of the emission angle of the fission fragments. The main features of this setup are discussed and results on the fission fragment angular distribution are provided for the Th-232(n,f) reaction around the fission threshold. The results are compared with the available data in the literature, demonstrating the good capabilities of this setup.
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| 27. |
- Tarrío, Diego, et al.
(författare)
-
Neutron-induced fission cross sections of Th-232 and U-233 up to 1 GeV using parallel plate avalanche counters at the CERN n_TOF facility
- 2023
-
Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 107:4
-
Tidskriftsartikel (refereegranskat)abstract
- The neutron-induced fission cross sections of Th-232 and U-233 were measured relative to U-235 in a wide neutron energy range up to 1 GeV (and from fission threshold in the case of Th-232, and from 0.7 eV in case of U-233), using the white-spectrum neutron source at the CERN Neutron Time-of-Flight (n_TOF) facility. Parallel plate avalanche counters (PPACs) were used, installed at the Experimental Area 1 (EAR1), which is located at 185 m from the neutron spallation target. The anisotropic emission of fission fragments were taken into account in the detection efficiency by using, in the case of U-233, previous results available in EXFOR, whereas in the case of Th-232 these data were obtained from our measurement, using PPACs and targets tilted 45 degrees with respect to the neutron beam direction. Finally, the obtained results are compared with past measurements and major evaluated nuclear data libraries. Calculations using the high-energy reaction models INCL++ and ABLA07 were performed and some of their parameters were modified to reproduce the experimental results. At high energies, where no other neutron data exist, our results are compared with experimental data on proton-induced fission. Moreover, the dependence of the fission cross section at 1 GeV with the fissility parameter of the target nucleus is studied by combining those ( p, f) data with our (n, f) data on Th-232 and U-233 and on other isotopes studied earlier at n_TOF using the same experimental setup.
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| 28. |
- Boutoux, G., et al.
(författare)
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The SOFIA Experiment
- 2013
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Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3884 .- 1875-3892. ; 47, s. 166-171
-
Konferensbidrag (refereegranskat)abstract
- SOFIA (Study On FIssion with Aladin) is an innovative experimental programme on nuclear fission carried out at GSI. In August 2012, we used relativistic secondary beams of neutron-deficient actinides and pre-actinides provided by the FRS and studied their fission, induced by electromagnetic interaction, in inverse kinematics. This experiment will provide for the first time complete isotopic yields (nuclear charge and mass) for both fragments over a broad range of fissioning nuclei from 238Np down to 183Hg. In this article, we discuss the experimental set-up and present promising preliminary results.
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| 29. |
- Chatillon, A., et al.
(författare)
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Influence of proton and neutron deformed shells on the asymmetric fission of thorium isotopes
- 2022
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Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 106:2
-
Tidskriftsartikel (refereegranskat)abstract
- Mean values of the number of protons and neutrons of the primary fission fragments at scission are determined for the asymmetric fission of 16 fissioning isotopes, from Ac-219 up to Np-238. Our results confirm that the main asymmetric fission mode around the heavier uranium isotopes is indeed characterized by an average atomic number around (Z(H)) = 54 in the heavy fission fragments. However, they also unambiguously show a stabilization effect in the light fission fragments around (N-L) = 52-54 in the neutron-deficient thorium and actinium isotopes. This is a clear signature that these deformed proton and neutron shell closures around 54 play a major role in the nuclear fission process. The evolution along the thorium chain shows that the neutron shell appears to be dominant in the asymmetric fission of the lighter thorium isotopes, in contrast to the heavier thorium isotopes for which the stabilization originates from the proton shell.
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| 30. |
- Diakaki, M., et al.
(författare)
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Fission Activities at the CERN n_TOF Facility
- 2018
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Ingår i: Fission And Properties Of Neutron-Rich Nuclei. - : World Scientific. - 9789813229433 ; , s. 529-537
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Konferensbidrag (refereegranskat)abstract
- A major part of the scientific program of the CERN n_TOF facility involves the study of neutron-induced fission reactions, which is essential for nuclear technology, as well as for the development of the theoretical models of fission. An overview of the fission studies performed and the corresponding detection systems is given, with a short description of the latest highlights.
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| 31. |
- Giot, L., et al.
(författare)
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Isotopic production cross sections of the residual nuclei in spallation reactions induced by 136Xe projectiles on proton at 500 A MeV
- 2013
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Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 899, s. 116-132
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Tidskriftsartikel (refereegranskat)abstract
- Around 270 medium-mass residual nuclei, formed in spallation reactions induced by 136Xe projectiles impinging on a liquid hydrogen target at 500 A MeV, have been unambiguously identified at GSI using the magnetic spectrometer FRS. The individual production cross sections and the longitudinal momentum distributions have been determined with high accuracy. These data represent an important constraint for theoretical models describing spallation reactions. © 2013 Elsevier B.V.
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| 32. |
- Gorbinet, T., et al.
(författare)
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A sample of the results of the first SOFIA experiment
- 2015
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Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3884 .- 1875-3892. ; 64, s. 101-106
-
Konferensbidrag (refereegranskat)abstract
- The first SOFIA experiment (Studies On FIssion with Aladin) was performed in August 2012 at GSI. The fission of several neutron-deficient actinides and pre-actinides was induced in flight at 700 A MeV by electromagnetic excitation. The use of inverse kinematics provides both high detection and high geometrical efficiency. The complete identification of both fission fragments in coincidence (nuclear charge and mass) was obtained over a broad range of fissioning nuclei. After a short introduction and description of the experimental setup, the quality of the charge and mass separation is presented, followed by some results concerning the Coulex-induced fission of U-234 and U-235. (C) 2015 Published by Elsevier B.V.
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| 33. |
- Jurado, B., et al.
(författare)
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Investigation of the surrogate-reaction method via the simultaneous measurement of gamma-emission and fission probabilities
- 2017
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 146
-
Konferensbidrag (refereegranskat)abstract
- We present the results of two experiments where we have measured for the first time simultaneously the fission and gamma-decay probabilities induced by different surrogate reactions. In particular, we have investigated the 238 U(d,p), 238 U( 3 He,t) and 238 U( 3 He, 4 He) reactions as surrogates for the neutron-induced n + 238 U, n + 237 Np and n + 236 U reactions, respectively. In the region where gamma emission, neutron emission and fission compete, our results for the fission probabilities agree fairly well with the neutron-induced data, whereas our gamma-decay probabilities are significantly higher than the neutron-induced data. The interpretation of these results is not obvious and is discussed within the framework of the statistical model with preliminary results for calculated spin-parity distributions populated in surrogate reactions. We also present future plans for surrogate-reaction studies in inverse kinematics with radioactive-ion beams at storage rings.
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| 34. |
- Pellereau, E., et al.
(författare)
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SOFIA: An innovative setup to measure complete isotopic yield of fission fragments
- 2013
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 62
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Konferensbidrag (refereegranskat)abstract
- We performed an experiment dedicated to the accurate isotopic yield measurement of fission fragments over the whole range. SOFIA exploits the inverse kinematics technique: using heavy ion beams at relativistic energies, fission is induced by Coulomb excitation in a high-Z target. The fragments are emitted forward and both of them are identified in charge and mass. The setup will be presented, as well as preliminary spectra. © Owned by the authors, published by EDP Sciences, 2013.
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| 35. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Fission of highly excited nuclei investigated in complete kinematic measurements
- 2013
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 62
-
Konferensbidrag (refereegranskat)abstract
- Fission is an extremely complex mechanism that requires a dynamical approach to describe the evolution of the process in terms of intrinsic and collective excitations of the nuclear constituents. In order to determine these effects a complex experimental setup was mounted at GSI, which allowed us for the first time the full identification in charge and mass of all fission fragments thanks to a magnetic separation and the use of the inverse kinematic technique. Moreover, we also measured the neutron multiplicities and the light-charged particles emitted in coincidence with fission. These complete kinematic measurements will be used to define sensitive observables to dissipative and transient effects in fission. In this manuscript we present the first results for the total fission cross sections. © Owned by the authors, published by EDP Sciences, 2013.
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| 36. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Proton-induced fission cross sections on Pb-208 at high kinetic energies
- 2014
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 90:6, s. Art. no. 064606-
-
Tidskriftsartikel (refereegranskat)abstract
- Total fission cross sections of Pb-208 induced by protons have been determined at 370A, 500A, and 650A MeV. The experiment was performed at GSI Darmstadt where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to determine these cross sections with an uncertainty below 6%. This result was achieved by an accurate beam selection and registration of both fission fragments in coincidence which were also clearly distinguished from other reaction channels. These data solve existing discrepancies between previous measurements, providing new values for the Prokofiev systematics. The data also allow us to investigate the fission process at high excitation energies and small deformations. In particular, some fundamental questions about fission dynamics have been addressed, which are related to dissipative and transient time effects.
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| 37. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Transient effects in fission investigated with proton-on-lead reactions in complete kinematic measurements
- 2015
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Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3884 .- 1875-3892. ; 64, s. 157-162
-
Konferensbidrag (refereegranskat)abstract
- Proton-induced fission of Pb-208 has been investigated at 370, 500 and 650 A MeV in complete kinematic measurements. The experiment was performed at GSI Darmstadt where the combined use of the inverse kinematics technique with an efficient detection setup allowed to measure for the first time the atomic and mass number of both fission fragments. The performed measurement together with different model calculations allow us to investigate dissipative and transient effects in the fission process and the dependence on temperature and deformation of the dissipation strength beta. The use of spallation reactions with lead projectiles favours this study due to its high excitation energy and low angular momentum. (C) 2015 The Authors. Published by Elsevier B.V.
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| 38. |
- Benlliure, J., et al.
(författare)
-
New experimental approaches to investigate the fission dynamics
- 2016
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Ingår i: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. - 9780735414112 ; 1753
-
Konferensbidrag (refereegranskat)abstract
- The first ever achieved full identification of both fission fragments, in atomic and mass number, made it possible to define new observables sensitive to the fission dynamics along the fission path up to the scission point. Moreover, proton-induced fission of 208Pb at high energies offers optimal conditions for the investigation of dissipative, and transient effects, because of the high-excitation energy of the fissioning nuclei, its low angular momentum, and limited shape distortion by the reaction. In this work we show that the charge distribution of the final fission fragments can constrain the ground-to-saddle dynamics while the mass distribution is sensitive to the dynamics until the scission point.
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| 39. |
- Farget, F., et al.
(författare)
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Transfer-induced fission in inverse kinematics: Impact on experimental and evaluated nuclear data bases
- 2015
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 51:12, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- Inverse kinematics is a new tool to study nuclear fission. Its main advantage is the possibility to measure with an unmatched resolution the atomic number of fission fragments, leading to new observables in the properties of fission-fragment distributions. In addition to the resolution improvement, the study of fission based on nuclear collisions in inverse kinematics beneficiates from a larger view with respect to the neutron-induced fission, as in a single experiment the number of fissioning systems and the excitation energy range are widden. With the use of spectrometers, mass and kinetic-energy distributions may now be investigated as a function of the proton and neutron number sharing. The production of fissioning nuclei in transfer reactions allows studying the isotopic yields of fission fragments as a function of the excitation energy. The higher excitation energy resulting in the fusion reaction leading to the compound nucleus Cf-250 at an excitation energy of 45MeV is also presented. With the use of inverse kinematics, the charge polarisation of fragments at scission is now revealed with high precision, and it is shown that it cannot be neglected, even at higher excitation energies. In addition, the kinematical properties of the fragments inform on the deformation configuration at scission.
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| 40. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Complete characterization of the fission fragments produced in reactions induced by Pb 208 projectiles on proton at 500A MeV
- 2015
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 91:6
-
Tidskriftsartikel (refereegranskat)abstract
- The two fragments produced in fission reactions induced by Pb208 projectiles impinging on a liquid hydrogen target at 500AMeV have been fully identified in coincidence. The experiment was performed at GSI Darmstadt, where the combined use of the inverse kinematics technique with an efficient detection setup permitted one to detect and to fully identify the fission fragments in a range from Z=27 to Z=52. The corresponding isotopic cross sections and velocities of the fission fragments were measured with high accuracy. The results are compared to state-of-the-art model calculations that reproduce the measured observables. Correlations between the two fragments were used to assess the role of charge polarization and the excitation energy gained by the nascent fragments using the neutron excess of the final fragments. The analysis of the average velocities of the fission fragments allowed us to parametrize the distance between the two fission fragments at scission as a function of the size of the fissioning system.
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| 41. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Constraining the level density using fission of lead projectiles
- 2015
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 92:4
-
Tidskriftsartikel (refereegranskat)abstract
- The nuclear level density is one of the main ingredients for the statistical description of the fission process. In this work, we propose to constrain the description of this parameter by using fission reactions induced by protons and light ions on Pb208 at high kinetic energies. The experiment was performed at GSI (Darmstadt), where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to measure the atomic number of the two fission fragments in coincidence. This measurement permitted us to obtain with high precision the partial fission cross sections and the width of the charge distribution as a function of the atomic number of the fissioning system. These data and others previously measured, covering a large range in fissility, are compared to state-of-the-art calculations. The results reveal that total and partial fission cross sections cannot unambiguously constrain the level density at ground-state and saddle-point deformations and additional observables, such as the width of the charge distribution of the final fission fragments, are required.
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| 42. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Dissipative effects in fission investigated in complete kinematics measurements
- 2017
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759890200 ; 146
-
Konferensbidrag (refereegranskat)abstract
- The study of dissipative effects in fission has been carried out with fusion-fission reactions by using a limited number of observables, such as the fission probabilities, the mass distribution of the fission fragments, or the neutron multiplicities. However, the large angular momenta gained by the compound nucleus in this kind of reaction could affect the conclusions drawn from such experiments. In this work, we propose to investigate the fission dynamics by the use of spallation reactions on 208Pb because the fissioning systems are produced with low angular momentum, small deformations, and high excitation energies, enhancing the dissipative effects. The complete kinematics measurements of the fission fragments and light-charged particles were performed by the use of the SOFIA setup combined with the inverse kinematics technique, allowing us for the first time a full indentification in atomic and mass number of the two fission fragments. These measurements permit us to define new fission observables for the investigation of the temperature and deformation dependencies of the dissipation parameter.
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| 43. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Dissipative effects in fission investigated with proton-on-lead reactions
- 2016
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9788874381012 ; 117, s. Art. no. 08017-
-
Konferensbidrag (refereegranskat)abstract
- The complete kinematic measurement of the two fission fragments permitted us to investigate dissipative effects at large deformations, between the saddle-point and the corresponding scission configurations. Up to now, this kind of study has only been performed with fusionfission reactions using a limited number of observables, such as the mass distribution of the fission fragments or the neutron multiplicities. However, the large angular momenta gained by the compound nucleus could affect the conclusions drawn from such experiments. In this work, the use of spallation reactions, where the fissioning systems are produced with low angular momentum, small deformations and high excitation energies, favors the study of dissipation, and allowed us to define new observables, such as postscission neutron multiplicities and the neutron excess of the final fission fragments as a function of the atomic number of the fissioning system. These new observables are used to investigate the dissipation at large deformations.
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| 44. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Fission dynamics at high excitation energies investigated in complete kinematics measurements
- 2017
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 863:1, s. Article no 012047-
-
Konferensbidrag (refereegranskat)abstract
- Light-charged particles emitted in proton-induced fission reactions on 208 Pb have been measured at different kinetic energies: 370A, 500A, and 650A MeV. The experiment was performed by the SOFIA collaboration at the GSI facilities in Darmstadt (Germany). The inverse kinematics technique was combined with a setup especially designed to measure light-charged particles in coincidence with fission fragments. The data were compared with different model calculations to assess the ground-to-saddle dynamics. The results confirm that transient and dissipative effects are required for an accurate description of the fission observables.
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| 45. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Light charged particles emitted in fission reactions induced by protons on Pb-208
- 2016
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 94:3
-
Tidskriftsartikel (refereegranskat)abstract
- Light charged particles emitted in proton-induced fission reactions on Pb-208 have been measured at different kinetic energies: 370A, 500A, and 650A MeV. The experiment was performed by the SOFIA Collaboration at the GSI facilities in Darmstadt (Germany). The inverse kinematics technique was combined with a setup especially designed to measure light charged particles in coincidence with fission fragments. This measurement allowed us, for the first time, to obtain correlations between the light charged particles emitted during the fission process and the charge distributions of the fission fragments. These correlations were compared with different model calculations to assess the ground-to-saddle dynamics. The results confirm that transient and dissipative effects are required for an accurate description of the fission observables.
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| 46. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Presaddle and postsaddle dissipative effects in fission using complete kinematics measurements
- 2016
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 94:6
-
Tidskriftsartikel (refereegranskat)abstract
- A complete kinematics measurement of the two fission fragments was used for the first time to investigate fission dynamics at small and large deformations. Fissioning systems with high excitation energies, compact shapes, and low angular momenta were produced in inverse kinematics by using spallation reactions of lead projectiles. A new generation experimental setup allowed for the first full and unambiguous identification in mass and atomic number of both fission fragments. This measurement permitted us to accurately determine fission cross sections, the charge distribution, and the neutron excess of the fission fragments as a function of the atomic number of the fissioning system. These data are compared with different model calculations to extract information on the value of the dissipation parameter at small and large deformations. The present results do not show any sizable dependence of the nuclear dissipation parameter on temperature or deformation.
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| 47. |
- Rodriguez-Tajes, C., et al.
(författare)
-
Isotopic distributions of fission fragments from transfer-induced fission
- 2013
-
Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3884 .- 1875-3892. ; 47, s. 125-130
-
Konferensbidrag (refereegranskat)abstract
- Fissioning systems from U to Cm as well as 250Cf were produced by 238U+12C transfer and fusion reactions. The detection of the target-like transfer partner made the characterization of the fissioning systems in (Z, A) and excitation energy possible. The isotopic identification of the fission fragments was achieved by using the VAMOS spectrometer combined to with reactions in inverse kinematics. Results regarding the populated transfer channels and excitation of the target-like transfer partner are presented, as well as the 240Pu fission probability. Isotopic yields of the fission-fragments for 240,*241Pu and 250Cf, having excitation energies of about 10 and 45 MeV, respectively, are discussed.
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| 48. |
- Sguazzin, M., et al.
(författare)
-
Determining neutron-induced reaction cross sections through surrogate reactions at storage rings
- 2023
-
Ingår i: Journal of Physics: Conference Series. - 1742-6588 .- 1742-6596. ; 2586:1
-
Konferensbidrag (refereegranskat)abstract
- Determining the cross sections of neutron-induced reactions on short-lived nuclei is imperative to rate calculations in stellar nucleosynthesis and applications of nuclear physics. It is also an immense experimental challenge due to the radioactivity of the targets involved. Our goal is to circumvent this obstacle by using surrogate reactions in inverse kinematics at the heavy-ion storage rings of GSI/FAIR. We present here preliminary results from the first proof of principle experiment, where a beam of 208Pb impinged on a H2 gas jet target in the Experimental Storage Ring (ESR).
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| 49. |
- Sguazzin, M., et al.
(författare)
-
Indirect measurements of neutron -induced reaction cross sections at heavy -ion storage rings
- 2023
-
Ingår i: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - 2100-014X. ; 284
-
Konferensbidrag (refereegranskat)abstract
- Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars and for applications in nuclear technology. However, their measurement is very complicated due to the radioactivity of the targets involved. We propose to circumvent this problem by using the surrogate reaction method in inverse kinematics, where the nucleus formed in the neutroninduced reaction of interest is produced by a reaction involving a radioactive heavy -ion beam and a stable, light target nucleus. The probabilities as a function of the compound -nucleus excitation energy for y -ray emission, neutron emission and fission, which can be measured with the surrogate reaction, are particularly useful to constrain model parameters and to obtain more accurate predictions of the neutron-induced reaction cross sections of interest. Yet, the full development of the surrogate method is hampered by numerous longstanding target issues, which can be solved by combining surrogate reactions with the unique and largely unexplored possibilities at heavy -ion storage rings. In this contribution, we describe the developments we are carrying out to measure for the first time simultaneously y-ray emission, neutron emission and fission probabilities at the storage rings of the GSI/FAIR facility. In particular, we will present the first results of the proof of principle experiment, which we performed in June 2022 at the Experimental Storage Ring (ESR)
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| 50. |
- Sguazzin, M., et al.
(författare)
-
Indirect measurements of neutron-induced reaction cross sections at storage rings
- 2023
-
Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
-
Konferensbidrag (refereegranskat)abstract
- Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars. However, their measurement is very difficult due to the radioactivity of the targets involved. We propose to circumvent this problem by using for the first time the surrogate reaction method in inverse kinematics at heavy-ion storage rings. In this contribution, we describe the developments we have done to perform surrogate-reaction studies at the storage rings of GSI/FAIR. In particular, we present the first results of the proof of principle experiment, which we conducted recently at the Experimental Storage Ring (ESR).
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