Joseph Frost-Schenk
(University of York)
26/06/2018, 19:00
Poster
15N(α,γ)19F is known to be one of the key formation mechanisms of 19F in AGB stars [1]. 19F may also be produced through this reaction in other stars such as Wolf-Rayet stars [2]. The 19F abundance observed in the stellar spectra strongly depends on the conditions in the astrophysical site. Its nucleosynthetic origin has been debated for several decades, however the understanding of the...
Thomas Chillery
(University of Edinburgh)
26/06/2018, 19:00
Poster, Grant assigned
Proton-induced reactions on 7Be play an important role in nuclear astrophysics studies related to solar neutrinos. Recent Earth-bound experiments measuring solar neutrino fluxes from the Sun show discrepancies between both within each other and with the standard solar model (SSM). Of the reactions involved in the production of solar neutrinos, the 7Be(p,g)8B still carries the largest...
Lihua Chen
(China Institute of Atomic Energy),
Weiping Liu
(China Institute of Atomic Energy)
26/06/2018, 19:00
Poster
Direct measurement of the cross sections for the key nuclear reactions is crucial for obtaining benchmark data for stellar model, verifying extrapolation model, constraining theoretical calculations, and solving key scientific questions in nuclear astrophysics. However, reaction cross-sections of the astrophysical reactions are extremely small. Tiny reaction rates in laboratories at the...
Viviana Mossa
(Bari University & INFN)
26/06/2018, 19:00
Poster
Deuterium is the first nucleus produced in the Universe, whose accumulation marks the beginning of the so called Big Bang Nucleosynthesis (BBN). Presently the main obstacle to an accurate theoretical deuterium abundance evaluation is due to the poor knowledge of the 2H(p,g)3He cross section at BBN energies.
The fusion cross section of the reaction is under studying at LUNA (Laboratory for...
157.
A collapsar model with disk wind: implications for supernovae associated with a gamma-ray burst
Tomoyasu Hayakawa
(Kyoto University)
26/06/2018, 19:00
Poster
We construct a simple but self-consistent collapsar model for gamma-ray bursts (GRBs) and SNe associated with GRBs (GRB-SNe).Our model includes a black hole, an accretion disk, and the envelope surrounding the central system.The evolutions of the different components are connected by the transfer of the mass and angular momentum. To address properties of the jet and the wind-driven SNe, we...
Panagiotis Gastis
(Central Michigan University)
26/06/2018, 19:00
Poster
Neutrino driven winds (NDW) in core-collapse supernovae (CCSN) constitute an important astrophysical environment for nucleosynthesis, especially for the formation of elements beyond iron. If the right proton-rich conditions are found in the wind, nuclei with atomic numbers up to Z~50 can be produced via the so called neutrino-p (vp-) process. The strength of vp-process depends on a few key...
Alain Coc
(CSNSM Orsay)
26/06/2018, 19:00
Poster
Now that the number of neutrino families and the baryonic density have been fixed by laboratory measurements or CMB observations, big bang nucleosynthesis has no free parameter.
Hence, it is possible to accurately calculate the abundances of the produced light elements.
It is now well known that there is a, yet unexplained, discrepancy of a factor of approx 3 between the primordial...
Stefan Pavetich
(The Australian National University)
26/06/2018, 19:00
Poster
Zirconium isotopes are predominantly produced by the slow neutron capture process. Maxwellian averaged cross sections (MACS) for neutron capture in the keV region are one of the key parameters to model this astrophysical process. They are particularly interesting in the mass region between 90-100 amu, as this is the matching area between the main and the weak component of the \text-process,...
Tibor Norbert Szegedi
(ATOMKI)
26/06/2018, 19:00
Poster, Grant assigned
Alpha-nucleus optical model potentials (OMP) are widely used in nuclear reaction network calculations aiming at the study of the gamma-process [1] and the weak r-process [2]. Considerable theoretical and experimental effort has been devoted in recent years to improve the knowledge of the OMP’s in order to give correct predictions for the cross sections and reaction rates [3,4] (and references...
Hannah Brinkman
(Konkoly Observatory, Hungary)
26/06/2018, 19:00
Poster, Grant assigned
Aluminium-26, a radioactive isotope with a half life of 0.72 Myr, was present in the early Solar System, as inferred from 26 Mg excess in meteorites, see e.g. [1]. It is also detected in the Galaxy via γ-ray observations from COMPTEL and INTEGRAL, see [2]. While it is known that 26 Al is produced in stars, many uncertainties are left related to the production sites and the nuclear physics...
Heshani Jayatissa
(Texas A&M University)
26/06/2018, 19:00
Poster
The 22Ne(alpha,n) reaction is a very important neutron source reaction for the slow neutron capture process (s-process) in asymptotic giant branch stars. Direct measurements are extremely difficult to carry out at Gamow energies due to the extremely small reaction cross section. The large uncertainties introduced when extrapolating direct measurements at high energies down to the Gamow...
Thomas Hensel
(Helmholtz-Zentrum Dresden-Rossendorf)
26/06/2018, 19:00
Poster, Grant assigned
One important component of the ambient background in underground laboratories are neutrons, which may cover a wide energy range from thermal up to 100 MeV and may affect γ-ray spectra for example by capture and inelastic scattering processes. Underground with more than a few meters rock overburden, cosmic-ray neutrons are removed, and the remaining flux is due to neutron production by...
Boris Pritychenko
(Brookhaven National Laboratory)
26/06/2018, 19:00
Poster
Evaluated Nuclear Data File (ENDF) libraries contain complete collections of reaction cross sections, angular distributions, fission yields and decay data. These data collections have been used worldwide in nuclear industry and national security applications. It represents a great interest to explore the recently-released ENDF/B-VIII.0 library for nuclear astrophysics purposes and compare...
Tamás Szücs
(Helmholtz-Zentrum Dresden-Rossendorf)
26/06/2018, 19:00
Poster
A new underground accelerator facility is being built in tunnels VIII and IX of the Dresden Felsenkeller. Previous gamma-ray background measurements in another part of the tunnel system showed suitable conditions for in-beam nuclear astrophysics experiments [1,2] using germanium detectors with active veto against the cosmic-ray muons. These stable ion beam experiments are of high importance to...
Stephanie Lyons
(National Superconducting Cyclotron Laboratory)
26/06/2018, 19:00
Poster
The r process is known to produce roughly half of the abundance of the isotopes of heavy elements. Models of the r-process depend upon theoretical calculations of various nuclear properties such as those from QRPA and Hauser-Feshbach. Sensitivity studies have shown that the final abundance distributions of r-process nuclei are greatly impacted by uncertainties in nuclear masses,...
Elia Lizeth Morales Gallegos
(INFN Napoli)
26/06/2018, 19:00
Poster
12C+12C reactions are among the most important processes in the evolution and nucleosynthesis of massive stars. The measurement of these reactions at astrophysical energies is very challenging due to their extremely small cross sections, heavy resonant structure and the presence of natural hydrogen and deuterium contaminants in the carbon targets. To date, no measurement of the 12C+12C...
Hannah Yasin
(Technische Universität Darmstadt)
26/06/2018, 19:00
Poster
Core-collapse supernovae represent one of the most energetic events in the universe and are the production site of many elements. The evolution during and after the supernova explosion is key for nucleosynthesis. In both phases, the equation of state (EOS) plays an
important role determining the contraction and cooling of the neutron star and thus affecting the ejecta conditions. However, the...
Maximilian Witt
(Technische Universität Darmstadt)
26/06/2018, 19:00
Poster
Core-collapse supernovae play a central role in the chemical history of the universe: they eject alpha elements that are produced during the life of massive stars, produce iron group elements and probably also elements up to Silver or even higher in some extreme cases. In order to investigate the nucleosynthesis occurring in core-collapse supernova, multidimensional simulations are required...
Aleksandra Ćiprijanović
(Department of Astronomy, Faculty of Mathematics, University of Belgrade)
26/06/2018, 19:00
Cosmology and big bang nucleosynthesis
Poster, Grant assigned
Lithium is one of the few elements produced in the Big Bang Nucleosynthesis (BBN), but it is the only one with the expected primordial abundances that do not match the observed values measured in low-metallicity environments, like in the Milky Way halo stars. Recently, the first lithium detection outside of the Milky Way was made in the low-
metallicity gas of the Small Magellanic Cloud....
Tijana Prodanovic
(University of Novi Sad)
26/06/2018, 19:00
Poster
It has been shown that galactic interaction and mergers can result in large-scale tidal shocks that propagate through interstellar gas. As a result, this can give rise to a new population of cosmic rays, additional to standard galactic cosmic rays present in star-forming galaxies. We investigate the impact of this tidal cosmic-ray population on the nucleosynthesis of lite elements. We...
György Gyürky
(ATOMKI)
26/06/2018, 19:00
Poster
After tremendous experimental and theoretical efforts and significant progress in astrophysical modeling, the origin of the heavy, proton rich isotopes -- the p nuclei -- is still not fully understood. One thing is certain: improved knowledge of the nuclear reactions rates entering the p-process models is crucial. A systematic study of low energy proton and alpha induced reactions on heavy...
Adriana Banu
(James Madison University)
26/06/2018, 19:00
Poster
The photodisintegration reaction cross-sections for 94Mo(γ,n) and 90Zr(γ,n) have been experimentally investigated with quasi-monochromatic photon beams at the High Intensity γ-Ray Source (HIγS) facility, Triangle University Nuclear Laboratory (TUNL). The measurements were focused primarily on studying the energy dependence of the photoneutron cross sections, which is the most direct way of...
Broxton Miles
(North Carolina State University)
26/06/2018, 19:00
Poster
With the advent of high-cadence, full-sky surveys, the number of observed transient events has increased at an astonishing rate.
Though the majority of these events display light curves and spectra that fit within the normal classification schemes, a growing number require further explanation.
Pair-instability supernovae (PISNe), the disruption of very high-mass (>100Msolar) stars by...
Felix Heim
(Institute for Nuclear Physics, University of Cologne)
26/06/2018, 19:00
Poster
In order to understand and describe the astrophysical processes that are responsible for the nucleosynthesis of all different kinds of elements a precise knowledge of cross sections and reaction rates is necessary.
However, in particular the network of the gamma-process, which plays an important role in the nucleosynthesis of the majority of the p nuclei, includes so many different reactions...
Thomas Rauscher
(University of Basel & University of Hertfordshire)
26/06/2018, 19:00
Poster
The Monte Carlo (MC) framework PizBuin was developed to study nuclear uncertainties by postprocessing large reaction networks with trajectories obtained from a variety of nucleosynthesis sites. We perform large-scale MC variations using temperature-dependent rate uncertainties combining experimental and theoretical uncertainties. From detailed statistical analyses, realistic uncertainties on...
David Rapagnani
(PG)
26/06/2018, 19:00
Poster
Motivations beyond the ERNA upgrade with a focus on its new jet target development
Jeremias Garcia Duarte
(INFN Napoli)
26/06/2018, 19:00
Poster, Grant assigned
Stellar model calculations are extremely sensitive to the rate of 12C(alpha,gamma)16O. Although great efforts were devoted to decrease the uncertainty in the extrapolations, more precise data are needed to provide a good input to the stellar models. The available data indicate that its cross section at E0 = 300 keV is dominated by E1 and E2 radiative capture processes into the 16O ground...
Federico Ferraro
(Genova University & INFN)
26/06/2018, 19:00
Poster
The 22Ne(p,gamma)23Na reaction takes part in the neon-sodium cycle of hydrogen burning and may affect the observed anticorrelation between sodium and oxygen abundances in globular cluster stars. Its rate is controlled by a number of low-energy resonances and a slowly varying non-resonant component. Three new resonances at Ep = 156.2, 189.5, and 259.7 keV, respectively, have recently been...
Giovanni Francesco Ciani
(Gran Sasso Science Institute)
26/06/2018, 19:00
Poster
13C(α, n)16O reaction is the main neutron source of the s process, which is responsible for the synthesis of about half of the heavy (A> 58) nuclei in the universe. This process takes place in the interiors of low mass AGB stars, with temperatures between 90 and 100 MK, corresponding to Gamow energies in the range of 140 and 230 keV.
The direct measurement of the 13C(α,n)16O reaction cross...
Dag Fahlin Strömberg
(Technische Universität Darmstadt)
26/06/2018, 19:00
Poster
In intermediate-mass stars (∼8–10 solar masses), carbon burning results in degenerate cores composed mostly out of oxygen and neon (ONe cores). Lighter stars in this mass range will shed their stellar envelopes and end as ONe white dwarfs. For heavier stars, the ONe cores will keep accumulating mass from the surrounding carbon-burning shell. The ultimate fate of this latter evolutionary path...
Adelle Goodwin
(Monash University)
26/06/2018, 19:00
Poster
Type I X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in low-mass X-ray binaries. They are highly energetic (sim 10^38 erg) events and so can release energy in the form of neutrinos. The neutrino flux released during an X-ray burst comes primarily from beta-decays. Using KEPLER, a 1D implicit hydrodynamics code that calculates the full nuclear reaction...
Inma Dominguez
(Universidad de Granada)
26/06/2018, 19:00
Poster
We study the explosion of rotating sub-Chandrasekhar mass white dwarfs using three-dimensional hydrodynamic simulations. High rotational speeds are assumed in order to significantly distort the initial spherical geometry of the white dwarf. Unlike spherically symmetric models, when He-ignition is located far from the spinning axis the detonation wave trains arrive asynchronously to the...
Shin-ichiro Fujimoto
(National Institute of Technology Japan)
26/06/2018, 19:00
Poster
We have investigated explosive nucleosynthesis in core-collapse supernovae (SNe) of massive stars, based on two-dimensional (2D) hydrodynamic simulations of the SN explosion.
Employing a simplified light-bulb scheme for neutrino transport and excising a central part of a proto-neutron star (PNS), we follow long-term evolution of the SN explosion over 1.0 second after the core bounce for 22...
Athanasios Psaltis
(McMaster University)
26/06/2018, 19:00
Poster
One of the important, but still unsettled topics in Nuclear Astrophysics is the production of the p-nuclei [1,2]. The p-process relies on an extended reaction network, which can be described theoretically by the Hauser-Feshbach statistical model, which in turn relies strongly on experimental data. To provide reliable data for p-nuclei, an experimental campaign at the Tandem Accelerator...
Daniel Robertson
(University of Notre Dame)
26/06/2018, 19:00
Poster
In the ongoing drive to extend the lower-energy limits of cross-section measurements in nuclear astrophysics, new techniques and facilities are required to enter or even approach the burning regime of interest for many astrophysically significant processes. Many unique approaches have been developed to overcome or navigate around the exponentially decreasing reaction probability at low energy...
Mous Dirk
(High Voltage Engineering Europa)
26/06/2018, 19:00
Poster
HVE has designed and built a dedicated 3.5 MV linear single-ended DC accelerator (Singletron) to satisfy the stringent demands of the LUNA MV project at LNGS (L’Aquila, Italy), in which nucleosynthesis is studied in the final Helium and Carbon burning stages that lead to the generation of heavy elements.
The beam current capability of the system include e.g. 1000 μA H+, 500 μA 4He+ (both 500...
Bernardo Becherini
(Perugia University)
26/06/2018, 19:00
Poster
The 19F(p,α)16O reaction is an important channel of fluorine destruction in H-rich environments as the outer layers of asymptotic giant branch (AGB) stars. Measurements of the 19F(p,α)16O reaction via the Trojan Horse Method (THM) have shown the presence of resonant structures not observed before [1,2,3]. As a consequence, the reaction rate at astrophysical temperatures (about 10^7−10^8 K)...
Xiaoting Fu
(University of Bologna & INAF - OAS)
26/06/2018, 19:00
Poster
Lithium is widely used as a tester to the cosmological model, a probe of stellar structure, and an age indicator of young stellar clusters. It is the very element that presents deep insights yet many problems to astrophysics. I will first introduce a stellar solution to the cosmological Li problem, which reveals that Li was first destroyed and re-accumulated by these stars shortly after they...
Esra Yuksel
(University of Zagreb & Yildiz Technical University)
26/06/2018, 19:00
Poster
Spin-isospin excitations are known as fundamental modes of excitation in nuclei that gained considerable attention with the advances in experimental facilities and progress in theoretical models. The detailed knowledge about their structure is important, not only for nuclear physics but also for the nuclear astrophysics. Especially, in the calculation of nuclear weak interaction processes...
Elia Lizeth Morales Gallegos
(NA),
Mauro Romoli
(NA)
26/06/2018, 19:00
Poster
A new detection array called GASTLY (GAs-Silicon Two-Layer sYstem) has been designed to detect and identify low-energy light charged-particles (p,d,alpha,...) emitted in nuclear reactions of astrophysical interest.
Devoted to the measurement of nano-barn cross-sections, the system is optimised for large solid angle coverage and for low-energy detection thresholds. The array consists of eight...
Klaus Stoeckel
(HZDR)
26/06/2018, 19:00
Poster
Recent, precise measurements of the primordial 2 H abundance [1] have opened thepossibility to precisely determine of the primordial baryon-to-photon ratio, independent from the cosmic microwave background. For their interpretation, the 2 H abundance data require equally precise nuclear data, in particular on the 2 H(p, γ) 3 He reaction.
Deep underground in the Gran Sasso laboratory, Italy,...
Ondrea Clarkson
(University of Victoria)
26/06/2018, 19:00
Poster, Grant assigned
Interactions between H- and He-shell convection layers have been seen in 1D stellar models of massive Pop III stars \cite{WW,LC} but until recently have not been investigated in detail. Using the 1D stellar evolution code \texttt{MESA}, we find that when this event occurs in a 45 \,\mathrm{M_Pop III model, it leads to H-burning luminosities of $\mathrm{\log L_HL_sim13$ due to...
Melanie Hampel
(Monash University)
26/06/2018, 19:00
Poster
The large majority of elements heavier than iron are formed by the slow (s) and rapid (r) neutron capture processes. However, it has become clear that a neutron capture process operating at neutron densities intermediate to the s and r process (i process) gives rise to its own characteristic abundance pattern. This i-process pattern is successful at reproducing observed heavy-element...
Nobuya Nishimura
(YITP, Kyoto University)
26/06/2018, 19:00
Poster
We evaluated the uncertainty relevant to nup-process nucleosynthesis using a Monte-Carlo centred approach. Based on a realistic and general prescription of temperature dependent uncertainty, we have examined the impact on the nup-process in several physical parameters of astrophysical models. We calculated the total uncertainty of final abundances caused by nuclear-physics inputs and...
Alvaro Tolosa Delgado
(IFIC (Instituto de Fisica Corpuscular))
26/06/2018, 19:00
Poster, Grant assigned
The distribution of solar system elemental abundances, after correction for s-process contributions, shows a maximum around A ∼ 80 sometimes called the 1 st r-process abundance peak. However the origin of the elements contributing to this peak is uncertain and several astrophysical processes have been proposed. Observations in ancient ultra metal poor stars [1] indicate that other mechanisms...
Magne Guttormsen
(University of Oslo)
26/06/2018, 19:00
Poster
The playground for the nucleosynthesis is found in the interior of stars
and/or in extreme cosmic events. The major contributors to creating heavier elements are the neutron capture processes.
The key question for these processes is whether the nuclear system after neutron absorption will keep the neutron and emitting gamma rays to dissipate the energy, or will it eject the neutron or other...
Julia Bliss
(TU Darmstadt)
26/06/2018, 19:00
Poster
Despite the rapid progress in supernova simulations and experimental nuclear astrophysics the astrophysical and nuclear physics uncertainties are still large and critically affect the nucleosynthesis. Thus, we address both sources of uncertainty and investigate their influence on the nucleosynthesis in neutron-rich neutrino-driven supernova ejecta. Our systematic study of the astrophysical...
Yudong Luo
(University of Tokyo)
26/06/2018, 19:00
Poster, Grant assigned
Cosmological theory of Big Bang nucleosynthesis (BBN) predicts the right amount of production of the light elements 2H, 3He, 4He, and 7Li in the early universe to constrain several cosmological parameters. We find that the abundance of these elements can be affected strongly by a stochas- tic primordial magnetic field (PMF) whose strength is spatially inhomogeneous. We assume a large-scale...
Shimizu Hideki
(Center for Nuclear Study, the University of Tokyo)
26/06/2018, 19:00
Poster
26mathrmAl is known as the first specific radioactivity detected via characteristic beta-delayed gamma-ray by astronomical telescopes.
Despite a lot of effort over the past three decades, the particular production sites of galactic 26Al are not well understood and there is a discrepancy between observations and theories on estimated abundance of 26mathrmAl in the interstellar medium.
Its...
Sebastian Urlass
(CERN)
26/06/2018, 19:00
Poster, Grant assigned
The fundamental role played by the 13 C(alpha,n)16O reaction rate in the understanding of stellar nucleosynthesis processes is widely recognized. Heavy elements (90 < A < 204) are produced in light Asymptotic Giant Branch (AGB) stars, with masses M/M_sun< 3, by the slow neutron capture process (s-process), which main source of neutrons is precisely the 13C(alpha,n)16O reaction. Therefore, an...
Steffen Turkat
(IKTP, TU Dresden)
26/06/2018, 19:00
Poster
The 3He(a,g)7Be reaction affects the nucleosynthesis of 7Li as well as the predicted solar 7Be and 8B neutrino fluxes. It is being studied over a wide energy range at the Rossendorf 3 MV Tandetron accelerator, with a focus on the measurement of the gamma-ray angular distribution at E=1 MeV.
There are multiple and overlapping precise experimental data sets at E=0.7-1.3 MeV. Any extrapolation...
Jose Francisco Favela Perez
(INFN Catania)
26/06/2018, 19:00
Poster
Measuring very small partial widths of carbon-12 from the Hoyle and the 9.6 MeV states above the particle emission threshold are of astrophysical interest because only after such decay carbon-12 is formed after a triple alpha process [1]. In the reaction α+ 12 C → α+( 12 C^∗ +γ) we used a multi-particle coincidence technique, developed with 4π multi-detector CHIMERA, in order to suppress the...
Fabio Marzaioli
(INFN Napoli)
26/06/2018, 19:00
Poster
Isotope fingerprints represents an attractive target for examining the nucleosynthetic origins of Solar System material, relating differentiated and primitive meteorite types, and studying mixing processes in the early solar nebula. Among the others chemical elements, Nickel is a moderately refractory and siderophile element, and also a major component of both iron and silicate meteorites,...
Claudia Travaglio
(INAF - OATO)
26/06/2018, 19:00
Poster
The explosion of massive stars as core-collapse supernovae represents one of the outstanding problems in modern astrophysics. Core-collapse supernovae figure prominently in the chemical evolution of galaxies as the dominant producers of elements between oxygen and the iron group, and they play an important role in the production of elements heavier than Fe. They represent a key ingredient in...
Jeffery Blackmon
(Louisiana State University)
26/06/2018, 19:00
Poster
Many of the atoms with atomic mass numbers 60 A 90 have their origins in the weak s process occurring in massive stars. The abundances produced in the weak s process are sensitive to individual neutron capture cross sections that can have a broad impact on nucleosynthesis. There is limited neutron capture cross section data especially at energies relevant for shell carbon burning near kT...
Zac Johnston
(Monash University)
26/06/2018, 19:00
Poster
In recent years, multizone simulations have been used to successfully model various observed features of thermonuclear X-ray bursts on neutron stars (NS), including recurrence times, burst energies, and lightcurve profiles. Although previous multizone studies have explored the dependence of burst properties on system parameters, and compared individual models with observations, no large-scale...
Iolanda Indelicato
(INFN-LNS)
26/06/2018, 19:00
Poster
The 19Fp,alpha_0 16O is the main fluorine destruction channel at the bottom of the convective envelope in Asymptotic Giant Branch (AGB). Because of the Coulomb barrier, direct measurements cannot access to the energy region of astrophysical interest (below 500 keV). We report on the indirect measurement of the alpha_0 channel using the Trojan Horse Method (THM).
Before THM measurement, only...
John Dermigny
(University of North Carolina)
26/06/2018, 19:00
Poster
The observational evidence for multiple stellar populations within globular clusters continues to confound the astronomical community.
These populations are usually interpreted as distinct generations, with the currently observed second-generation stars having formed in part from the ejecta of massive, first-generation ``polluter" stars, giving rise to anomalous abundance patterns. The...
Marius Eichler
(Technische Universitaat Darmstadt)
26/06/2018, 19:00
Poster
The recent observation of an optical afterglow (“kilo- or macronova”) in the aftermath of the gravitational wave event GW170817 has confirmed that neutron star mergers are an operating site of the r-process. In such an event, energy that is released in nuclear reactions during the r-process can thermalize with the ejecta and act as a heating
source. This feedback of energy influences the...
Kanji Mori
(National Astronomical Observatory of Japan)
26/06/2018, 19:00
Poster, Grant assigned
The 12C+12C reaction is one of the most important reactions in astrophysics. The reaction ignites type Ia supernovae (SNe Ia), which are used as a standard candle in cosmology and are the major factory of the iron group elements in galaxies. In addition, it is a possible fuel of X-ray superbursts, whose ignition mechanism is still unclear.
In spite of its importance, the cross sections of...
E. T. Li
(Shenzhen University)
26/06/2018, 19:00
Poster
The ground state of the unstable 26Al nucleus (26Alg) with T_1/2 = 0.717 Myr was the first radioisotope detected in the galaxy, via the characteristic 1.809 MeV gamma-emission of 26Mg. The observation is direct proof of ongoing stellar nucleosynthesis in our Galaxy and indicates that there are approximately 2-3 M_odot of 26Alg. It is therefore fundamental to understand the production of 26Alg...
Debra Richman
(NSCL, Michigan State University)
26/06/2018, 19:00
Poster
60Fe is created by neutron capture in massive stars prior to core collapse supernova. This isotope is one of only a handful whose gamma-rays from β-decay indicate ongoing nucleosynthesis in the Galaxy [1]. For this reason the reactions involved for the creation and destruction of 60Fe in this environment must be well understood. Due to the short half-life of 59Fe it is challenging to perform a...
Nobuya Nishimura
(YITP, Kyoto University)
26/06/2018, 19:00
Poster
Magnetically driven supernovae of massive stars are expected as viable sites of heavy-nuclei including r-process nuclei as well as the central engine of gamma-ray bursts and magnetar formation supernovae. In this talk, I show recent results of r-process nucleosynthesis based on magneto-hydrodynamical models taking into account the enhancement processes of magnetic fields due to...
Ms
Borbála Cseh
(Konkoly Observatory, MTA CSFK)
26/06/2018, 19:00
Poster
Barium stars belong to a binary system where the companion star has evolved through the AGB phase and transferred elements heavier than Fe produced by the slow neutron-capture process onto the secondary star, which is now observed. A new large set of homogeneous high resolution spectra of Ba stars makes it now possible to meaningfully compare the observational data with different AGB models...
Pablo Jimenez Bonilla
(University of Seville)
26/06/2018, 19:00
Poster
Maxwellian-averaged cross-sections (MACS) are needed as an input for the models of stellar s- and r-processes nucleosynthesis. In many cases, MACS can be obtained from activation measurements, irradiating a flat sample with the neutron field generated by the 7Li(p,n)7Be reaction at 1912 keV proton energy (a quasi-maxwellian neutron spectrum or QMNS). In most measurements, the sample is placed...
Shuo Wang
(Shandong University)
26/06/2018, 19:00
Poster
Jinping Underground laboratory for Nuclear Astrophysics (JUNA) is one of the major research programs in China JinPing underground Laboratory (CJPL). To study key nuclear reactions in astrophysics, a new 400 kV accelerator, with high stability and high intensity, has already been constructed by CIAE and IMP in 2017 and will be installed into CJPL in 2019.
Currently, the beam characteristics...
Diego Vescovi
(GSSI & INFN Perugia)
26/06/2018, 19:00
Poster
Recent improvements in stellar models for intermediate-mass and massive stars are recalled, together with their expectations for the production of radioactive nuclei with lifetime tau 25 Myr, in order to re-examine the origins of now extinct radioactivities, found to be alive in the Early Solar System. While the inheritance from Galactic evolution broadly explains the concentrations of most...
Frank Leonel Bello Garrote
(University of Oslo)
26/06/2018, 19:00
Poster
For more than 20 years, researchers working at the Oslo Cyclotron Laboratory (OCL) have been dedicated, among other things, to exploring the statistical properties of nuclei in the quasi-continuum. Oslo-method experiments simultaneously provide experimental values of the nuclear level density and the γ-strength function of nuclei [1], both necessary ingredients for (n,γ) cross section...
Jenny Feige
(Technical University Berlin)
26/06/2018, 19:00
Poster
Each year, roughly 30,000 tons of extraterrestrial solid material, liberated from larger parent bodies within our Solar System, is captured by the Earth [1]. A significant fraction of this material are submillimetre-sized spherical to teardrop-shaped particles, termed micrometeorites. They represent signatures of asteroidal collisions and cometary sublimation [2], hence, the determination of...
246.
Presolar SiC grains of Type AB with isotopically light nitrogen: Contributions from supernovae?
Peter Hoppe
(Max Planck Institute for Chemistry)
26/06/2018, 19:00
Poster
Primitive solar system materials contain small concentrations of presolar grains that formed in the winds of evolved stars and in the ejecta of stellar explosions [1]. Presolar SiC is the best studied presolar mineral. Among them are so-called Type AB grains which have low 12C/13C ratios of <= 10. This population of presolar SiC grains appears to originate from multiple types of stellar...
Daniel Bemmerer
(Helmholtz-Zentrum Dresden-Rossendorf)
26/06/2018, 19:00
Poster
Low-background experiments with stable ion beams are an important tool for putting the model of stellar hydrogen, helium, and carbon burning on a solid experimental foundation. The pioneering work in this regard has been done by the LUNA collaboration at Gran Sasso, using a 0.4 MV accelerator. The present contribution reviews the status of the project for a higher-energy underground...
Javier Balibrea Correa
(INFN Napoli)
26/06/2018, 19:00
Poster
The success of low counting rate experiments strongly depends on the accurate knowledge and reduction of the backgrounds present during the measurement campaigns. For this reason, dark matter search and low energy nuclear astrophysics experiments are performed in underground laboratories, shielded from the cosmic rays. Two important examples of low counting rate experiments for nuclear...
Kevin Ebinger
(GSI)
26/06/2018, 19:00
Poster
Core-collapse supernovae (CCSNe) are energetic explosions occurring at the end of the evolution of massive stars that provide the conditions for the synthesis of elements beyond iron and contribute to the galactic chemical evolution. Decades of research have not fully uncovered the detailed mechanism behind these complex explosions. Multi-dimensional simulations are crucial to investigate the...
Sanjana Curtis
(North Carolina State University)
26/06/2018, 19:00
Poster
Core-collapse supernovae (CCSNe) are one of the most important sites of element synthesis in the universe. Not only do they drive the chemical evolution of galaxies, the nucleosynthesis yields of CCSNe are also imprinted on some of the oldest stars. However, our ability to predict nucleosynthesis yields is limited by the still unresolved question of the CCSN explosion mechanism. The PUSH...
Toshio Suzuki
(Nihon University)
26/06/2018, 19:00
Poster
R-process nucleosynthesisin core-collapse supernova explosions (CCSNe) and binary neutron star mergers (NSMs), both of which are promissing candidates for the r-process sites, are studied using new beta-decay half-lives for the waiting-point nuclei obtained by shell-model calculations.
We here investigate how the change of beta-decay half-lives affects the r-process nucleoasynthesis. Beta...
Athanasios Psaltis
(McMaster University)
26/06/2018, 19:00
Poster
The origin of about 35 neutron-deficient stable isotopes with mass number A 74, known as the p-nuclei, has been a long-standing puzzle in nuclear astrophysics. The νp-process is a candidate for the production of the light p-nuclei, but it presents high sensitivity to both supernova dynamics and nuclear physics [1,2]. It has been recently shown that the breakout from pp-chains through the...
Nicole Vassh
(University of Notre Dame)
26/06/2018, 19:00
Poster
The recent observations of the GW170817 electromagnetic counterpart suggest lanthanides were produced in this neutron star merger event. Lanthanide production in heavy element nucleosynthesis is subject to large uncertainties from nuclear physics and astrophysics unknowns. Specifically, the rare-earth abundance peak, a feature of enhanced lanthanide production at A~164 seen in the solar...
Jacqueline den Hartogh
(Konkoly Observatory)
26/06/2018, 19:00
Poster
The slow neutron capture process (s-process) is responsible for about half of all ele- ments heavier than iron in the universe, and is therefore important for galactic chemical evolution. Its main production site is the Asymptotic Giant Branch (AGB) phase, a stellar evolution phase in stars with an initial mass between about 0.8 and 8 M⊙. As stars rotate, it is important to calculate stellar...
Rita Lau
(Technological and Higher Education Institute of Hong Kong)
26/06/2018, 19:00
Poster
In this paper, we investigate the sensitivities of positron decays on a one-zone model of type-I X-ray bursts. Most existing studies have multiplied or divided entire beta decay rates (electron captures and beta decay rates) by 10. Instead of using the standard Fuller and Fowler (FFNU) rates, we used the most recently developed weak library rates, which include rates from Langanke et al.'s...
Rita Lau
(Technolgical and Higher Education Institute of Hong Kong)
26/06/2018, 19:00
Poster
R-process is responsible for nearly half of the production of heavy elements in the universe. The nuclear input in the r-process is important in simulating formation of elements in the Universe. One of the properties is the excited states of nuclei in beta decays. There was study on the topic but using semi-gross theory and the single particle states were calcuated by theory as well as the...
Johnson Liang
(McMaster University)
26/06/2018, 19:00
Poster
In classical nova nucleosythesis repeated proton capture reactions and beta-decays produce proton-rich isotopes and the endpoint of this nucleosynthesis typically occurs in nuclei close to A ~ 40. There is currently a discrepancy between the observed and predicted isotopic abundances in this mass region. One particular reaction, 38-K(p,g)39-Ca is important in this regard. Nova simulations...
Moshe Tessler
(Hebrew University of Jerusalem)
26/06/2018, 19:00
Poster
As part of a program of neutron-capture measurements in the regime of the weak s-process, we studied for the first time the 36,38Ar(n,gamma) reactions in the stellar neutron energy regime and their contribution to production of light neutron-rich nuclides.
The experiments were performed with the Liquid-Lithium Target (LiLiT) and the mA-proton beam at 1.92 MeV (2-3 kW) from the Soreq Applied...
Scilla Degl'Innocenti
(Pisa University & INFN)
26/06/2018, 19:00
Poster
The complete understanding of the surface stellar abundances of light elements (lithium, beryllium, and boron) represents one of the most interesting open problems in astrophysics. These elements are gradually destroyed at different depths of stellar interior mainly by (p,alpha) burning reactions thus their surface abundances are strongly influenced by the nuclear burnings as well as by the...
Anastasiia Chekhovska
(V.N. Karazin Kharkiv National University)
26/06/2018, 19:00
Poster, Grant assigned
The nuclei of the overwhelming majority of the occurring in nature stable isotopes of medium and heavy chemical elements were synthesized in hot stars during the scenarios of rapid and slow neutron capture, that is (n,gamma)-reactions, and following beta-decays. However, in the formation of a so-called {p-nuclei} group including the 112Sn nuclide, simple photonuclear reactions of the...
Koh Takahashi
(Argelander Institute for Astronomy)
26/06/2018, 19:00
Poster
After the onset of hydrodynamical collapse due to electron-positron pair creation, a very-massive star forming a massive CO core of ~65-120 Msun is considered to explode as a pair-instability supernova (PISN) [1]. Peculiar chemical yields as well as the high explosion energy characterize the PISN explosion [2,3].
Our final goal is to prove the existence of PISN and thus the high mass nature...
Rin Yokoyama
(University of Tennessee)
26/06/2018, 19:00
Poster
Beta-delayed one- and two-neutron branching ratios (P1n and P2n) are measured in the decay of 86Ga and 87Ga at the RI-beam Factory at RIKEN Nishina Center using a high-efficiency array of 3He neutron counters (BRIKEN). Two-neutron emission is observed in the decay of 87Ga for the first time. The large P1n value of 87,86Ga compared to P2n is interpreted as a signature of dominating one neutron...
Sebastian Hammer
(HZDR Dresden-Rossendorf)
26/06/2018, 19:00
Poster, Grant assigned
The amount of deuterium produced in Big Bang Nucleosynthesis depends sensitively on cosmological parameters such as the baryon energy density and the effective number of neutrino species. The recently improved precision of astronomical measurements of the primordial deuterium abundance calls also for more precise nuclear data. Currently, the precision of the Big Bang abundance prediction of 2H...
Antonio Caciolli
(Padova University & INFN)
26/06/2018, 19:00
Poster
The 22Ne(alpha,gamma)26Mg is the competitor of the 22Ne(alpha,n)25Mg in AGB stars. The 22Ne(alpha,n)25Mg is an efficient source of neutrons for s-process in medium masses AGB.
There is significant uncertainty in the 22Ne(alpha,gamma)26Mg thermonuclear reaction rate. This has been clearly remarked by the presence of this particular reaction in the COST Action called ChETEC (CA16117) that...
Jørgen E. Midtbø
(University of Oslo)
26/06/2018, 19:00
Poster
gamma-ray strength functions are one of the key nuclear physics inputs to constrain (n,gamma) cross-sections for unstable nuclei relevant to different neutron-capture nucleosynthesis processes. This is of particular importance for the r process, where the process flow proceeds through neutron-rich nuclei far from stability. It has been shown that the presence of a low-energy enhancement, seen...
Moshe Gai
(University of Connecticut)
26/06/2018, 19:00
Poster
Over the last four decades conflicting data plagued our attempts to deduce the cross section of the 12C(a,g) reaction at low energies and did not allow an accurate extrapo-lation of the astrophysical s-factor to stellar energies. In particular conflicting data did not allow us to chose between the high value (∼80 keVb) and the low value (∼10 keVb) solutions of the E1 s-factor at stellar...
Rosanna Depalo
(INFN Padova)
26/06/2018, 19:00
Poster
HEAT (Hydrogen dEsorption from cArbon Targets) is a new project started in 2018 with the aim of studying the desorption of hydrogen and deuterium contaminations from carbon targets used for Nuclear Astrophysics studies, with special reference to the 12C+12C fusion reaction.
12C+12C fusion is the dominant process during stellar carbon burning and its cross section is a crucial parameter in...
Etienne Kaiser
(Keele University)
26/06/2018, 19:00
Poster
Convection plays a key role in stellar evolution by both transporting energy and mixing composition. Convective mixing alters the internal structure and lengthens significantly the duration of burning stages when it is present. Convective boundary mixing is crucial for the creation of the 13C pocket in low-mass stars (main s-process site) and to determine the extent of convective zones in...
Leonel Morejon
(DESY)
26/06/2018, 19:00
Poster
The Ultra high energy cosmic rays (UHECRs) interact with the photon fields of the sources in which they are produced and with the background photons of the extragalactic space. We show the experimental situation on photo-nuclear cross section data and demonstrate that the available measurements are sparse in the relevant mass range for the UHECRs. Moreover, the theoretical models that describe...
Marcel Grieger
(Helmholtz-Zentrum Dresden-Rossendorf)
26/06/2018, 19:00
Poster
In order to determine the cross sections of astrophysical reactions at relevant energies pioneering work has been done at LUNA using a 0.4 MV accelerator. The new Felsenkeller laboratory, Germany, will house a 5 MV Pelletron accelerator with stable and intense ion beams in a low background environment to extend on this framework. For this purpose two ion sources are going to be part of the...
Viktor Szaszkó-Bogár
(University of Szeged, Hungary)
26/06/2018, 19:00
Poster
In the past decades, new types of extremely luminous transients were revealed by astronomical surveys. One of them is the so-called tidal disruption event (TDE). When a star approaches a supermassive black hole (BH) within a critical distance (the tidal radius), tidal forces tear the star apart. When the stellar debris falls back onto the BH, the release of the potential energy generates a...
Laszlo Csedreki
(LNGS)
26/06/2018, 19:00
Poster
The 13C(α,n)16O reaction is very important in the astrophysical context. This reaction is the dominant neutron source for the synthesis of the main s-process component of heavy elements, taking place in thermally pulsing, low-mass asymptotic giant branch stars. The aim of the current LUNA campaign is the determination of the reaction cross section towards the Gamow window with an accuracy of...
Felix Ludwig
(Helmholtz-Zentrum Dresden-Rossendorf)
26/06/2018, 19:00
Poster, Grant assigned
Muons, which are produced by cosmic rays in the atmosphere, are highly penetrating and are only mitigated by the roughly 50 m of rock above the shallow underground laboratory Felsenkeller in Dresden, Germany.
In order to determine the precise flux and angular distribution amount of muons reaching the tunnels of Felsenkeller, a portable muon detector developed and built by the REGARD group [1]...
Andre Sieverding
(Technische Universität Darmstadt)
26/06/2018, 19:00
Poster
Neutrinos play a curcial role for core-collapse supernova explosions and their nucleosynthesis.
All flavors of neutrinos are emitted from the hot and dense environment of a collapsing massive star in such tremendous numbers that they not only help to revive the explosion shock wave but also affect the composition of the outer layers of the star that have been chemically enriched during the...
Adrià Casanovas
(Universitat Politecnica de Catalunya)
26/06/2018, 19:00
Poster
About half of the elemental abundances between Fe and Bi are produced by the so-called s (slow) process of neutron capture reactions in AGB stars. Of particular importance are some nuclides produced during the s-process which are radioactive, with half-lives from years to Gy, so its decay process competes with the neutron capture chain: these nuclides are known as branching points. The...
Mallory Smith
(NSCL / Michigan State University)
26/06/2018, 19:00
Poster
Neutron-capture rates are critical for models of the astrophysical r-process, yet are difficult to measure directly and often outside the current realm of capability for experimental facilities. Meanwhile, theoretical extrapolations can vary by orders of magnitude even near stability. For example, predicted rates in the Mn-Ga mass region can vary by factors of 10 or more \cite{Liddick}. Nuclei...
Yonglin Zhu
(North Carolina State University)
26/06/2018, 19:00
Poster
The detection of an electromagnetic counterpart to GW170817[1] suggests that r-process elements are produced in neutron star mergers. This electromagnetic counterpart has been modeled as a kilonova, which is a light curve thought to be powered mainly from the radioactive decay of heavy elements formed. We investigate uncertainties in the nuclear physics inputs to kilonova calculations, 1nding...
Giuseppe D'Agata
(INFN - LNS)
26/06/2018, 19:00
Poster
19F production and destruction pathways in astrophysic environment is crucial: it is, in fact, the least abundant element in the 12leqAleq56 mass range, and therefore fluorine abundance can me used to test the models. 19F presence is observatively confirmed for low-mass AGB stars (M=2:4Modot), and model failed to reproduce the observed abundance. This fact is probably due to extra mixing...
Gabriele Cescutti
(INAF Trieste)
26/06/2018, 19:00
Poster
We investigated the impact of uncertainties in neutron-capture and weak reactions (on heavy elements) on the s-process nucleosynthesis in low-mass stars using a Monte-Carlo based approach. We performed extensive nuclear reaction network calculations that include newly evaluated temperature-dependent upper and lower limits for the individual reaction rates. Consistent with previous studies, we...
Mirco Dietz
(University of Edinburgh)
26/06/2018, 19:00
Poster, Grant assigned
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 input for s-process studies. The 72Ge(n,g) Maxwellian Average Cross Section (MACS) has an important influence on production of isotopes between Ge and Zr in the s-process...
Lori Downen
(University of North Carolina)
26/06/2018, 19:00
Poster
A classical nova is a stellar explosion occurring between the white dwarf and the main sequence companion star of a binary system, and while it is suspected that these explosions are responsible for the galactic production of rare nuclear species, a number of open questions about their dynamics remain unanswered. Some knowledge of the nature of classical novae can be gained using traditional...
Gianpiero Gervino
(INFN Torino)
26/06/2018, 19:00
Poster
We investigate the possible thermodynamic instability in a warm and dense nuclear medium where a phase transition from nucleonic matter to resonance-dominated Delta-matter can take place. Such a phase transition is characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the isospin concentration) in asymmetric...
Gang Guo
(GSI, Germany)
26/06/2018, 19:00
Poster
An accurate description of neutrino interaction in hot and dense nuclear matter is important to dynamics of core-collapse supernova (CCSN) explosion and nucleosynthesis in CCSN as well as neutron star mergers (NSMs). In this work, improvements regarding neutrino opacity calculations in different aspects are studied. Firstly, higher order weak interaction terms like weak magnetism and...
Alex Gnech
(Gran Sasso Science Institute)
26/06/2018, 19:00
Poster
The 6Li abundance measured in the atmosphere of metal-poor stars is three orders of magnitude larger than predicted by the theory of Standard Big Bang Nucleosythesis (SBBN) predictions [1]. Even if the results of the astronomical measurements are still under debate [2-4], the knowledge of the cross section (or astrophysical S-factor) of the reactions that contribute to determine the 6Li...
Bruce Fegley
(Washington University)
26/06/2018, 19:00
Poster
The relative abundances of volatile to refractory elements are easily affected by condensation and evaporation and therefore thermochemical equilibrium calculations are important to quantitatively evaluate fractionations between gases and solids in astronomical environments. Fegley and Lewis (1980 Icarus) computed condensation temperatures for P, F, Cl, Na, and K in the solar nebula using...
Masahiko Katsuma
(Osaka City University)
26/06/2018, 19:00
Poster
The subthreshold 1^-_1 state at an excitation energy E_x = 7.12 MeV in 16O has been believed to enhance the astrophysical S-factor for 12C(alpha,gamma_0)16O. The enhancement seems to originate from strong interference between 1^-_1 and 1^-_2 (E_x ~ 9.6 MeV) in the vicinity of the alpha-particle threshold. However, the weak interference between two states and a resulting small E1 S-factor are...
Maria Lugaro
(Konkoly Observatory)
26/06/2018, 19:00
Poster
Female role models reduce the impact on women of “stereotype threat” [1], i.e., of “being at risk of confirming, as a self-characteristic, a negative stereotype about one’s social group” [2]. This can lead women scientists to underperform or to leave their scientific career because of negative stereotypes such as that they are not as talented or interested in science as men. Sadly, history...
