1,554 research outputs found

    Conceptual design of the AGATA 2ŌÄ array at LNL

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    Conceptual design of the AGATA 2<math display="inline" id="d1e396" altimg="si24.svg"><mi>ŌÄ</mi></math> array at LNL

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    International audienceThe Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1ŌÄ, and progressively the number of ATCs will increase up to a 2ŌÄ angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem‚ÄďPIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy ő≥-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL

    Sub-barrier fusion in C12+Mg26,24 : Hindrance and oscillations

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    Background: The existence of fusion hindrance in the light heavy-ion systems of astrophysical interest is not well established, so investigating slightly heavier cases may allow a reliable extrapolation towards the lighter ones. The recent observation of a very high hindrance threshold in 12 C + 24 Mg (with a positive Q value for fusion) at ŌÉfus 0.75 mb, misses a valid interpretation within current theoretical models. Purpose: Our aim has been to search evidence for fusion hindrances in the nearby system 12 C + 26 Mg also having Qfus > 0, and to obtain information on the underlying physics from a comparison of the two cases and from coupled-channels calculations. Methods: The experiment was performed in inverse kinematics using the 26 Mg beam from the XTU Tandem accelerator of Laboratori Nazionali di Legnaro (LNL). The targets were thin 12 C evaporations isotopically enriched to 99.9%. The fusion-evaporation residues were detected at small angles by a E - E -ToF detector telescope following an electrostatic beam deflector. Results: The fusion excitation function of 12 C + 26 Mg has been measured down to ‚Čą5 őľb. The astrophysical S factor shows a maximum at an energy where the cross section is ‚Čą0.03 mb, significantly lower than for 12 C + 24 Mg. This difference is confirmed by the comparison of the two S factors. coupled channel calculations give a good account of the data, but they overpredict the cross sections below ‚Čą0.03 mb. The logarithmic slopes of the two excitation functions are superimposable to a large extent, with visible oscillations, more noticeable for 12 C + 24 Mg. Conclusions: The hindrance phenomenon is clearly observed in 12 C + 26 Mg. The difference between the corresponding threshold energies for 12 C + 24,26 Mg might (only qualitatively) be attributed to the őĪ-like structure of 24 Mg. In the Jiang‚Äôs phenomenological systematics, the different behaviors of 12 C + 24,26 Mg make the situation more complex, and call into question the extrapolation procedure toward the lighter systems of astrophysical interest

    Conceptual design of the AGATA 2<math display="inline" id="d1e396" altimg="si24.svg"><mi>ŌÄ</mi></math> array at LNL

    No full text
    International audienceThe Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1ŌÄ, and progressively the number of ATCs will increase up to a 2ŌÄ angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem‚ÄďPIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy ő≥-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL

    Are Football Players More Prone to Muscle Injury after COVID-19 Infection? The "Italian Injury Study" during the Serie a Championship

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    Introduction: Football was the first sport to resume competitions after the coronavirus disease 2019 (COVID-19) lockdown and promptly the hypothesis was raised of a potential relationship between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and musculoskeletal injuries in athletes. This study aimed to confirm the association between SARS-CoV-2 infection and muscle strain injury in a large population of elite football players and to investigate if the COVID-19 severity level could affect the risk of injury. Methods: A retrospective cohort study involving 15 Italian professional male football teams was performed during the Italian Serie A 2020-2021 season. Injuries and SARS-CoV-2 positivity data were collected by team doctors through an online database. Results: Of the 433 included players, we observed 173 SARS-CoV-2 infections and 332 indirect muscle strains. COVID-19 episodes mostly belonged to severity level I and II. The injury risk significantly increased after a COVID-19 event, by 36% (HR = 1.36, CI95% 1.05; 1.77, p-value = 0.02). The injury burden demonstrated an 86% increase (ratio = 1.86, CI95% 1.21; 2.86, p-value = 0.005) in the COVID-19 severity level II/III versus players without a previous SARS-CoV-2 infection, while level I (asymptomatic) patients showed a similar average burden (ratio = 0.92, CI95% 0.54; 1.58, p-value = 0.77). A significantly higher proportion of muscle-tendon junction injuries (40.6% vs. 27.1%, difference = 13.5%, CI95% 0.002%; 26.9%, p-value = 0.047) was found when comparing level II/III versus Non-COVID-19. Conclusions: This study confirms the correlation between SARS-CoV-2 infection and indirect muscle injuries and highlights how the severity of the infection would represent an additional risk factor

    Quasiprojectile breakup and isospin equilibration at Fermi energies: an indication of longer projectile-target contact times?

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    International audienceAn investigation of the quasiprojectile breakup channel in semiperipheral and peripheral collisions of 58,64^{58,64}Ni+58,64^{58,64}Ni at 32 and 52 MeV/nucleon is presented. Data have been acquired in the first experimental campaign of the INDRA-FAZIA apparatus in GANIL. The effect of isospin diffusion between projectile and target in the two asymmetric reactions has been highlighted by means of the isospin transport ratio technique, exploiting the neutron-to-proton ratio of the quasiprojectile reconstructed from the two breakup fragments. We found evidence that, for the same reaction centrality, a higher degree of relaxation of the initial isospin imbalance is achieved in the breakup channel with respect to the more populated binary output, possibly indicating the indirect selection of specific dynamical features. We have proposed an interpretation based on different average projectile-target contact times related to the two exit channels under investigation, with a longer interaction for the breakup channel. The time information has been extracted from AMD simulations of the studied systems coupled to GEMINI++: the model calculations support the hypothesis hereby presented

    Quasiprojectile breakup and isospin equilibration at Fermi energies: an indication of longer projectile-target contact times?

    No full text
    International audienceAn investigation of the quasiprojectile breakup channel in semiperipheral and peripheral collisions of 58,64^{58,64}Ni+58,64^{58,64}Ni at 32 and 52 MeV/nucleon is presented. Data have been acquired in the first experimental campaign of the INDRA-FAZIA apparatus in GANIL. The effect of isospin diffusion between projectile and target in the two asymmetric reactions has been highlighted by means of the isospin transport ratio technique, exploiting the neutron-to-proton ratio of the quasiprojectile reconstructed from the two breakup fragments. We found evidence that, for the same reaction centrality, a higher degree of relaxation of the initial isospin imbalance is achieved in the breakup channel with respect to the more populated binary output, possibly indicating the indirect selection of specific dynamical features. We have proposed an interpretation based on different average projectile-target contact times related to the two exit channels under investigation, with a longer interaction for the breakup channel. The time information has been extracted from AMD simulations of the studied systems coupled to GEMINI++: the model calculations support the hypothesis hereby presented

    Examination of cluster production in excited light systems at Fermi energies from new experimental data and comparison with transport model calculations

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    International audienceFour different reactions, 32^{32}S+12^{12}C and 20^{20}Ne+12^{12}C at 25 and 50 MeV/nucleon, have been measured with the FAZIA detector capable of full isotopic identification of most forward emitted reaction products. Fragment multiplicities, angular distributions and energy spectra have been measured and compared with Monte Carlo simulations, i.e. the antisymmetrized molecular dynamics (AMD) and the heavy-ion phase space exploration (HIPSE) models. These models are combined with two different afterburner codes (HFll and SIMON) to describe the decay of the excited primary fragments. In the case of AMD, the effect of including the clustering and inter-clustering processes to form bound particles and fragments is discussed. A clear confirmation of the role of cluster aggregation in the reaction dynamics and particle production for these light systems, for which the importance of the clustering process increases with bombarding energy, is obtained

    Quasiprojectile breakup and isospin equilibration at Fermi energies: an indication of longer projectile-target contact times?

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    An investigation of the quasiprojectile breakup channel in semiperipheral and peripheral collisions of 58,64^{58,64}Ni+58,64^{58,64}Ni at 32 and 52 MeV/nucleon is presented. Data have been acquired in the first experimental campaign of the INDRA-FAZIA apparatus in GANIL. The effect of isospin diffusion between projectile and target in the two asymmetric reactions has been highlighted by means of the isospin transport ratio technique, exploiting the neutron-to-proton ratio of the quasiprojectile reconstructed from the two breakup fragments. We found evidence that, for the same reaction centrality, a higher degree of relaxation of the initial isospin imbalance is achieved in the breakup channel with respect to the more populated binary output, possibly indicating the indirect selection of specific dynamical features. We have proposed an interpretation based on different average projectile-target contact times related to the two exit channels under investigation, with a longer interaction for the breakup channel. The time information has been extracted from AMD simulations of the studied systems coupled to GEMINI++: the model calculations support the hypothesis hereby presented

    Quasiprojectile breakup and isospin equilibration at Fermi energies: an indication of longer projectile-target contact times?

    No full text
    International audienceAn investigation of the quasiprojectile breakup channel in semiperipheral and peripheral collisions of 58,64^{58,64}Ni+58,64^{58,64}Ni at 32 and 52 MeV/nucleon is presented. Data have been acquired in the first experimental campaign of the INDRA-FAZIA apparatus in GANIL. The effect of isospin diffusion between projectile and target in the two asymmetric reactions has been highlighted by means of the isospin transport ratio technique, exploiting the neutron-to-proton ratio of the quasiprojectile reconstructed from the two breakup fragments. We found evidence that, for the same reaction centrality, a higher degree of relaxation of the initial isospin imbalance is achieved in the breakup channel with respect to the more populated binary output, possibly indicating the indirect selection of specific dynamical features. We have proposed an interpretation based on different average projectile-target contact times related to the two exit channels under investigation, with a longer interaction for the breakup channel. The time information has been extracted from AMD simulations of the studied systems coupled to GEMINI++: the model calculations support the hypothesis hereby presented
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