Exploració per tema "Nucleosynthesis"

Ara es mostren els items 1-20 de 50

    • 123-321 models of classical novae 

      José Pont, Jordi; Shore, Steven N.; Casanova Bustamante, Jordi (EDP Sciences, 2020-01-28)
      Article
      Accés obert
      Realitzat a/amb:   Università di Pisa
      Context. High-resolution spectroscopy has revealed large concentrations of CNO and sometimes other intermediate-mass elements (e.g., Ne, Na, Mg, or Al, for ONe novae) in the shells ejected during nova outbursts, suggesting ...

    • 7Be(n , p)7Li reaction and the cosmological lithium problem: measurement of the cross section in a wide energy range at n_TOF at CERN 

      Damone, L.; Barbagallo, Massimo; Mastromarco, M.; Calviño Tavares, Francisco; Casanovas Hoste, Adrià; Cortés Rossell, Guillem Pere; Tarifeño Saldivia, Ariel Esteban (American Institute of Physics (AIP), 2018-07-24)
      Article
      Accés obert
      We report on the measurement of the 7Be(n,p)7Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a ...

    • 7Be(n,alpha) and 7Be(n,p) cross-section measurement for the cosmological lithium problem at the n TOF facility at CERN 

      Barbagallo, Massimo; Colonna, Nicola; Aberle, O.; Calviño Tavares, Francisco; Casanovas Hoste, Adrià; Cortés Rossell, Guillem Pere; Tarifeño Saldivia, Ariel Esteban (EDP Sciences, 2016)
      Comunicació de congrés
      Accés obert
      The Cosmological Lithium Problem refers to the large discrepancy between the abundance of primordial 7Li predicted by the standard theory of Big Bang Nucleosynthesis and the value inferred from the so-called “Spite plateau” ...

    • Accretion onto Neutron Stars: Hydrodynamics and Nucleosynthesis 

      Moreno Guzmán, Fermín (Universitat Politècnica de Catalunya, 2009-11-25)
      Tesi
      Accés obert
      In the middle of the 70s, some authors suggested that accretion of hydrogen and helium rich material by a neutron star in a binary system, where the companion star would have low mass, could explain thermonuclear bursts ...

    • Approaching the precursor nuclei of the third r-process peak with RIBs 

      Domingo-Pardo, C; Agramunt Ros, Jorge; Algora, A.; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere (Institute of Physics (IOP), 2013)
      Comunicació de congrés
      Accés obert
      The rapid neutron nucleosynthesis process involves an enormous amount of very exotic neutron-rich nuclei, which represent a theoretical and experimental challenge. Two of the main decay properties that affect the final ...

    • Astrophysical Implications of the139La(n,gamma) and151Sm(n,gamma) Cross Section Measured at n_TOF 

      Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme (2006)
      Text en actes de congrés
      Accés obert
      The nuclear resonance parameters and the capture cross section of the neutron magic isotope 139La and of the radioactive isotope 151Sm have been measured relative to 197Au in the energy range of 0.6 eV-1 MeV at neutron ...

    • Astrophysics at n-TOF facility at CERN 

      Tagliente, G.; Abbondanno, U.; Aerts, G.; Calviño Tavares, Francisco; Pretel Sánchez, Carme (Institute of Physics (IOP), 2010)
      Text en actes de congrés
      Accés obert
      The neutron time of flight (n_TOF) facility at CERN is a spallation neutron source with white neutron energy spectrum (from thermal to several GeV), covering the full energy range of interest for nuclear astrophysics, in ...

    • Capture cross section measurements of 186,187,188-Os at n TOF: the resolved resonance region 

      Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme (EDP Sciences, 2007)
      Text en actes de congrés
      Accés obert
      The neutron capture cross sections of 186,187,188Os have been measured at the CERN neutron time-of-flight facility, n TOF, in the neutron energy range from 1 eV up to 1MeV. In this contribution, we report the results of ...

    • Coordinated analysis of two graphite grains from the CO3.0 LAP 031117 meteorite: First identification of a CO Nova graphite and a presolar iron sulfide subgrain 

      Haenecour, P.; Floss, C.; José Pont, Jordi; Amari, S.; Lodders, K.; Jadhav, M.; Wang, A.; Gyngard, F. (2016-07)
      Article
      Accés obert
      Presolar grains constitute remnants of stars that existed before the formation of the solar system. In addition to providing direct information on the materials from which the solar system formed, these grains provide ...

    • Detonations in white dwarf dynamical interactions 

      Aznar Siguan, Gabriela; García-Berro Montilla, Enrique; Lorén Aguilar, Pablo; José Pont, Jordi; Isern Vilaboy, Jordi (2013)
      Article
      Accés obert
      n old, dense stellar systems collisions of white dwarfs are a rather frequent phenomenon. Here we present the results of a comprehensive set of Smoothed Particle Hydrodynamics simulations of close encounters of white ...

    • Evidence for a sub-Chandrasekhar-mass type Ia supernova in the Ursa Minor dwarf galaxys 

      McWilliam, Andrew; Piro, Anthony; Badenes Montoliu, Carles; Bravo Guil, Eduardo (2018-04-19)
      Article
      Accés obert
      A long-standing problem is identifying the elusive progenitors of Type Ia supernovae (SNe Ia), which can roughly be split into Chandraksekhar and sub-Chandrasekhar-mass events. An important difference between these two ...

    • Explosion of white dwarfs harboring hybrid CONe cores 

      Bravo Guil, Eduardo; Gil Pons, Pilar; Gutiérrez Cabello, Jordi; Doherty, Carolyn L. (EDP Sciences, 2016-04-12)
      Article
      Accés obert
      Recently, it has been found that off-center carbon burning in a subset of intermediate-mass stars does not propagate all the way to the center, resulting in a class of hybrid CONe cores. The implications of a significant ...

    • First Measurement of 72Ge(n gamma) at n-TOF 

      Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Tarifeño Saldivia, Ariel Esteban (EDP Sciences, 2018)
      Text en actes de congrés
      Accés obert
      The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universe. Neutron capture cross sections on stable isotopes are a key nuclear physics ...

    • First measurement of beta-decay half-lives and neutron emission probabilities in several isotopes beyond N = 126 

      Caballero Folch, Roger (Universitat Politècnica de Catalunya, 2015-06-05)
      Tesi
      Accés obert
      In this work beta-decay half-lives and neutron-emission probability values have been experimentally determined for first time in several nuclei beyond the neutron-shell closure at N=126. To this aim the accelerator complex ...

    • First results of the140ce(N,¿)141ce cross-section measurement at n_tof 

      Amaducci, Simone; Colonna, Nicola; Cosentino, Luigi; Cristallo, Sergio; Finocchio, Elisabetta; Massimi, Cristian; Mastromarco, Mario; Aberle, O.; Alcayne Aicua, Víctor; Andrzejewski, Józef; Babiano Suárez, Víctor; Bacak, Michael; Barbagallo, Massimo; Berthoumieux, Eric; Calviño Tavares, Francisco; Casanovas Hoste, Adrià; Cortés Rossell, Guillem Pere (2021-06-01)
      Article
      Accés obert
      An accurate measurement of the 140Ce(n,¿) energy-dependent cross-section was performed at the n_TOF facility at CERN. This cross-section is of great importance because it represents a bottleneck for the s-process nucleosynthesis ...

    • Gamma rays from Type Ia supernova SN 2014j 

      Churazov, Eugene; Sunyaev, Rashid; Isern Vilaboy, Jordi; Bikmaev, I; Bravo Guil, Eduardo; Chugai, Nikolai; Grebenev, Sergei; Jean, Pierre; Knodlseder, Jurgen; Lebrun, François; Kuulkers, Eric (2015-10-08)
      Article
      Accés obert
      The whole set of INTEGRAL observations of Type Ia supernova SN 2014J, covering the period 19–162 days after the explosion, has been analyzed. For spectral fitting the data are split into early and late periods covering ...

    • Hydrogen burning of 29Si and its impact on presolar stardust grains from classical novae 

      Downen, Lori N.; Iliadis, Christian; Champagne, Art; Clegg, Thomas; Coc, Alain; José Pont, Jordi (Institute of Physics (IOP), 2022-04-01)
      Article
      Accés obert
      Presolar stardust grains found in primitive meteorites are believed to retain the isotopic composition of stellar outflows at the time of grain condensation. Therefore, laboratory measurements of their isotopic ratios ...

    • Level structure of the Tz=-1 nucleus Ar 34 and its relevance for nucleosynthesis in ONe novae 

      José Pont, Jordi (American Physical Society, 2021-03-08)
      Article
      Accés obert
      The 24Mg+12C fusion reaction was used to perform a detailed ¿-ray spectroscopy study of the astrophysically important nucleus 34Ar. In particular, an experimental setup, coupling the advanced ¿-ray tracking array GRETINA ...

    • Measurement of 73Ge(n,gamma) cross sections and implications for stellar nucleosynthesis 

      Lederer-Woods, C.; Battino, U.; Ferreira, P.A.; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Riego Pérez, Albert (Elsevier, 2019-03-10)
      Article
      Accés obert
      73Ge(n,gamma) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar ...

    • Measurement of the 24,25,26Mg(n, gamma) reaction cross-section at n-TOF 

      Massimi, Cristian; Andriamonje, S.; Andrzejewski, Józef; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Gómez Hornillos, María Belén (PoS - Proceedings of Science, 2010)
      Text en actes de congrés
      Accés obert
      We have measured the neutron-induced capture cross-section of the importants-process isotopesof magnesium. The measurement has been performed at the neutron time-of-flight facility n_TOFat CERN. From a preliminary analysis ...