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| 2. |
- Sguazzin, M., et al.
(author)
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Determining neutron-induced reaction cross sections through surrogate reactions at storage rings
- 2023
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In: Journal of Physics: Conference Series. - 1742-6588 .- 1742-6596. ; 2586:1
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Conference paper (peer-reviewed)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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| 3. |
- Sguazzin, M., et al.
(author)
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Indirect measurements of neutron -induced reaction cross sections at heavy -ion storage rings
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - 2100-014X. ; 284
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Conference paper (peer-reviewed)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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| 4. |
- Sguazzin, M., et al.
(author)
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Indirect measurements of neutron-induced reaction cross sections at storage rings
- 2023
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In: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
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Conference paper (peer-reviewed)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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| 7. |
- Sarmiento Pico, Luis, et al.
(author)
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Elucidating the nature of the proton radioactivity and branching ratio on the first proton emitter discovered 53mCo
- 2023
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In: Nature Communications. - 2041-1723. ; 14
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Journal article (peer-reviewed)abstract
- The observation of a weak proton-emission branch in the decay of the 3174keV 53mCo isomeric state marked the discovery of proton radioactivity in atomic nuclei in 1970. Here we show, based on the partial half-lives and the decay energies of the possible proton-emission branches, that the exceptionally high angular momentum barriers, lp = 9 and lp = 7, play a key role in hindering the proton radioactivity from 53mCo, making them very challenging to observe and calculate. Indeed, experiments had to wait decades for significant advances in accelerator facilities and multi-faceted state-of-the-art decay stations to gain full access to all observables. Combining data taken with the TASISpec decay station at the Accelerator Laboratory of the University of Jyväskylä, Finland, and the ACTAR TPC device on LISE3 at GANIL, France, we measured their branching ratios as bp1 = 1.3(1)% and bp2 = 0.025(4)%. These results were compared to cutting-edge shell-model and barrier penetration calculations. This description reproduces the order of magnitude of the branching ratios and partial half-lives, despite their very small spectroscopic factors.
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| 8. |
- Domínguez-Gil, B., et al.
(author)
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The Reality of Inadequate Patient Care and the Need for a Global Action Framework in Organ Donation and Transplantation
- 2022
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In: Transplantation. ; 106:11, s. 2111-2117
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Journal article (peer-reviewed)abstract
- BACKGROUND: Transplant therapy is considered the best and often the only available treatment for thousands of patients with organ failure that results from communicable and noncommunicable diseases. The number of annual organ transplants is insufficient for the worldwide need. METHODS: We elaborate the proceedings of the workshop entitled "The Role of Science in the Development of International Standards of Organ Donation and Transplantation," organized by the Pontifical Academy of Sciences and cosponsored by the World Health Organization in June 2021. RESULTS: We detail the urgency and importance of achieving national self-sufficiency in organ transplantation as a public health priority and an important contributor to reaching relevant targets of the United Nations Agenda for Sustainable Development. It details the elements of a global action framework intended for countries at every level of economic development to facilitate either the establishment or enhancement of transplant activity. It sets forth a proposed plan, by addressing the technical considerations for developing and optimizing organ transplantation from both deceased and living organ donors and the regulatory oversight of practices. CONCLUSIONS: This document can be used in governmental and policy circles as a call to action and as a checklist for actions needed to enable organ transplantation as treatment for organ failure. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.
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| 9. |
- Giovinazzo, J., et al.
(author)
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4D-imaging of drip-line radioactivity by detecting proton emission from 54mNi pictured with ACTAR TPC
- 2021
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Journal article (peer-reviewed)abstract
- Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.
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| 10. |
- Giovinazzo, J., et al.
(author)
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Proton 3D tracking and emission time from a short-lived isomer with ACTAR TPC
- 2022
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In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1042
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Journal article (peer-reviewed)abstract
- An experiment was conducted at the GANIL/LISE3 facility to produce the 10+ isomer of 54Ni and measure its proton radioactivity decay branches. The proton detection was achieved with the ACTAR TPC device that enabled the separation of the small signal of the emitted proton from the large signal of the implanted ion, while the decay half-life is of the order of 150 ns. From the measured data, the emitted proton track length and the decay time of the ion can be extracted simultaneously. The full proton radioactivity pattern could be established, with two emission branches and their relative branching ratio. Data processing and analysis that allowed to identify and separate the ion and the proton signals in order to reconstruct the particles trajectories and decay time are detailed. The evaluation of the detection efficiency for the proton radioactivity branches based on a full simulation is described.
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