| 1. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Systematic study of Δ (1232) resonance excitations using single isobaric charge-exchange reactions induced by medium-mass projectiles of Sn
- 2022
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Ingår i: Physical Review C. - 2469-9993 .- 2469-9985. ; 106:1
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Tidskriftsartikel (refereegranskat)abstract
- The fragment separator FRS has been used for the first time to measure the (n,p)- and (p,n)-type isobaric charge-exchange cross sections of stable Sn112,124 isotopes accelerated at 1A GeV with an uncertainty of 3% and to separate quasielastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic contribution can be associated to the excitation of isobar Δ(1232) resonances and to the pion emission in s wave, in both the target and projectile nuclei, while the quasielastic contribution is associated with the nuclear spin-isospin response of nucleon-hole excitations. The data lead to interesting results, where we observe a clear quenching of the quasielastic component, and their comparisons to theoretical calculations demonstrate that the baryonic resonances can be excited in the target and projectile nuclei. To go further in this investigation, we propose to study the excitation of baryonic resonances, taking advantage of the combination of high-resolving power magnetic spectrometers with the Wide Angle Shower Apparatus (WASA) calorimeter. These new measurements will allow us to determine the momenta of the ejectiles and pions emitted in coincidence after the single isobaric charge-exchange collisions, providing us unique opportunities to study the evolution of the baryonic resonance dynamics with the neutron-proton asymmetry through the use of exotic radioactive ion beams.
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| 2. |
- Audouin, L., et al.
(författare)
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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
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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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| 3. |
- Chatillon, A., et al.
(författare)
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Accurate measurements of fission-fragment yields in U-234,U-235,U-236,U-238(gamma,f) with the SOFIA set-up
- 2016
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759819706 ; 111
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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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| 4. |
- Grente, L., et al.
(författare)
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The SOFIA experiment: Measurement of 236U fission fragment yields in inverse kinematics
- 2016
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 122:01006
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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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| 5. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
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Knockout and fragmentation reactions using a broad range of tin isotopes
- 2017
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Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 96:3, s. Art no 034303 -
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Tidskriftsartikel (refereegranskat)abstract
- Production cross sections of residual nuclei obtained by knockout and fragmentation reactions of different tin isotopes accelerated at 1A GeV have been measured with the fragment separator (FRS) at GSI, Darmstadt. The new measurements are used to investigate the neutron-excess dependence of the neutron- and proton-knockout cross sections. These cross sections are compared toGlauber model calculations coupled to a nuclear de-excitation code in order to investigate the role of the remnant excitations. This bench marking shows an overestimation of the cross sections for the removal of deeply bound nucleons. A phenomenological increase in the excitation energy induced in the remnants produced in these cases allows us to reproduce the measured cross sections.
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| 6. |
- Benlliure, J., et al.
(författare)
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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
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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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| 7. |
- 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
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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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| 8. |
- Chatillon, A., et al.
(författare)
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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
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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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| 9. |
- Chatillon, A., et al.
(författare)
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Experimental study of nuclear fission along the thorium isotopic chain: From asymmetric to symmetric fission
- 2019
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Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 99:5
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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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| 10. |
- Chatillon, A., et al.
(författare)
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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
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Ingår i: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - 2100-014X. ; 284
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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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