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Present nuclear reaction network computations for astrophysical simulations involve many different types of rates, including neutron-capture reactions of interest for the modeling of heavy-element nucleosynthesis. While for many of them we still have to rely on theoretical calculations, an increasing number of experimentally-determined cross sections have now become available. In this contribution, we present “ASTrophysical Rate and rAw data Library” (ASTRAL), a new online database for neutron-capture cross sections based on experimental results, mainly obtained through activation and timeof-flight measurements. For the evaluation process, cross sections were re-calculated starting from raw data and by considering recent changes in physical properties of the involved isotopes (e.g., half-life and γ-ray intensities). We show the current status of the database, the techniques adopted to derive the recommended Maxwellian-averaged cross sections, and future developments.
Weigand, Mario ; Dellmann, Sophia Florence ; Brückner, Benjamin ; Erbacher, Philipp ; Eberhardt, Klaus ; Geppert, Christopher ; Heftrich, Tanja ; Kisselbach, Timo ; Kurtulgil, Cem Deniz ; Reich, Markus ; Reifarth, René ; Volknandt, Meiko
To determine the neutron flux in activation experiments, a commonly used monitor is zirconium and in particular the stable isotopes 94,96Zr. 96Zr is very sensitive to epithermal neutrons. Despite its widespread application, most gamma intensities of the radioactive neutron capture product, 97Zr, yield large uncertainties. With the help of a new γ spectroscopy setup and GEANT simulations, we succeeded in determining a new set of γ-ray intensities with significantly reduced uncertainties.
Moreno-Soto, Javier ; Valenta, Stanislav ; Berthoumieux, Eric ; Chebboubi, Abdelaziz ; Diakaki, Maria ; Dridi, Wissem ; Dupont, Emmeric ; Gunsing, Frank ; Krtička, Milan ; Litaize, Olivier ; Serot, Olivier ; Aberle, Oliver ; Alcayne, Victor ; Amaducci, Simone ; Andrzejewski, Józef ; Audouin, Laurent ; Bécares, Vicente ; Babiano Suarez, Victor ; Bacak, Michael ; Barbagallo, Massimo ; Thomas, Benedikt ; Bennett, Samuel ; Billowes, Jonathan ; Bosnar, Damir ; Brown, Adam ; Busso, Maurizio ; Caamano, Manuel ; Caballero Ontanaya, Luis ; Calviño Tavares, Francisco ; Calviani, Marco ; Cano-Ott, Daniel ; Casanovas Hoste, Adrià ; Cerutti, Francesco ; Chiaveri, Enrico ; Colonna, Nicola ; Cortés Rossell, Guillem Pere ; Cortés-Giraldo, Miguel Antonio ; Cosentino, Luigi ; Cristallo, Sergio ; Damone, Lucia Anna ; Davies, Paul John ; Dietz, Mirco ; Domingo-Pardo, César ; Dressler, Rugard ; Ducasse, Quentin ; Durán, Ignacio ; Eleme, Zinovia ; Fernández Domínguez, Beatriz ; Ferrari, Alfredo ; Finocchiaro, Paolo ; Furman, Valter ; Göbel, Kathrin ; Gawlik-Ramiega, Aleksandra ; Gilardoni, Simone ; Gonçalves, Isabel Maria Ferro ; González Romero, Enrique Miguel ; Guerrero Sánchez, Carlos ; Heinitz, Stephan ; Heyse, Jan ; Jenkins, David ; Junghans, Arnd Rudolf ; Käppeler, Franz ; Kadi, Yacine ; Kimura, Atsushi ; Knapova, Ingrid ; Kokkoris, Michael ; Kopatch, Yuri N. ; Kurtulgil, Cem Deniz ; Ladarescu, Ion ; Lampoudis, Christos ; Lederer-Woods, Claudia ; Lonsdale, Sarah Jane ; Macina, Daniela ; Manna, Alice ; Martinez, Trinitario ; Masi, Alessandro ; Massimi, Cristian ; Mastinu, Pierfrancesco ; Mastromarco, Mario ; Maugeri, Emilio Andrea ; Mazzone, Annamaria ; Mendoza Cembranos, Emilio ; Mengoni, Alberto ; Michalopoulou, Veatriki ; Milazzo, Paolo Maria ; Mingrone, Federica ; Musumarra, Agatino ; Negret, Alexandru ; Nolte, Ralf ; Ogállar Ruiz, Francisco ; Oprea, Andreea ; Patronis, Nikolas ; Pavlik, Andreas ; Perkowski, Jarosław ; Piersanti, Luciano ; Petrone, Cristina ; Pirovano, Elisa ; Porras, Ignacio ; Praena, Javier ; Quesada Molina, José Manuel ; Ramos Doval, Diego ; Rauscher, Thomas ; Reifarth, René ; Rochman, Dimitri ; Sabate-Gilarte, Marta ; Saxena, Alok ; Schillebeeckx, Peter ; Schumann, Dorothea ; Sekhar, Adhitya ; Smith, Alastair Gavin ; Sosnin, Nikolay V. ; Sprung, Peter ; Stamatopoulos, Athanasios ; Tagliente, Giuseppe ; Taı́n Enríquez, José Luis ; Tarifeno-Saldivia, Ariel ; Tassan-Got, Laurent ; Torres-Sanchez, Pablo ; Tsinganis, Andrea ; Ulrich, Jiri ; Urlaß, Sebastian ; Vannini, Gianni ; Variale, Vincenzo ; Vaz, Pedro ; Ventura, Alberto ; Vescovi, Diego ; Vlachoudis, Vasilis ; Vlastou, Rosa ; Wallner, Anton ; Woods, Philip John ; Wright, Tobias ; Žugec, Petar
Background: The photon strength functions (PSFs) and nuclear level density (NLD) are key ingredients for calculation of the photon interaction with nuclei, in particular the reaction cross sections. These cross sections are important especially in nuclear astrophysics and in the development of advanced nuclear technologies.
Purpose: The role of the scissors mode in the M1 PSF of (well-deformed) actinides was investigated by several experimental techniques. The analyses of different experiments result in significant differences, especially on the strength of the mode. The shape of the low-energy tail of the giant electric dipole resonance is uncertain as well. In particular, some works proposed a presence of the E1 pygmy resonance just above 7 MeV. Because of these inconsistencies additional information on PSFs in this region is of great interest.
Methods: The γ-ray spectra from neutron-capture reactions on the 234U, 236 U, and 238 U nuclei have been measured with the total absorption calorimeter of the n_TOF facility at CERN. The background-corrected sum-energy and multi-step-cascade spectra were extracted for several isolated s-wave resonances up to about 140 eV.
Results: The experimental spectra were compared to statistical model predictions coming from a large selection of models of photon strength functions and nuclear level density. No combination of PSF and NLD models from literature is able to globally describe our spectra. After extensive search we were able to find model combinations with modified generalized Lorentzian (MGLO) E1 PSF, which match the experimental spectra as well as the total radiative widths.
Conclusions: The constant temperature energy dependence is favored for a NLD. The tail of giant electric dipole resonance is well described by the MGLO model of the E1 PSF with no hint of pygmy resonance. The M1 PSF must contain a very strong, relatively wide, and likely double-resonance scissors mode. The mode is responsible for about a half of the total radiative width of neutron resonances and significantly affects the radiative cross section.
Wolf, Clemens ; Langer, Christoph ; Montes, Fernando ; Pereira, Jorge ; Ahn, Sunghoon ; Ayoub, Sara ; Bazin, Daniel ; Bender, Peter ; Brown, Alex ; Browne, Justin ; Crawford, Heather ; Deleeuw, Eric ; Elman, Brandon ; Fiebiger, Stefan ; Gade, Alexandra ; Gastis, Panagiotis ; Lipschutz, Samuel ; Longfellow, Brenden ; Nunes, Filomena ; Ong, Wei-Jia ; Poxon-Pearson, Terri ; Perdikakis, Georgios ; Reifarth, René ; Schatz, Hendrik ; Schmidt, Konrad ; Schmitt, Jaclyn ; Sullivan, Chris ; Titus, Rachel ; Weißhaar, Dirk ; Woods, Philip John ; Zamora Cardona, Juan Carlos ; Zegers, Remco G. T.
The 23Al(p, γ)24Si stellar reaction rate has a significant impact on the light-curve emitted in X-ray bursts. Theoretical calculations show that the reaction rate is mainly determined by the properties of direct capture as well as low-lying 2+ states and a possible 4+ state in 24Si. Currently, there is little experimental information on the properties of these states.
In this proceeding we will present a new experimental study to investigate this reaction, using the surrogate reaction 23Al(d,n) at 47 AMeV at the National Superconducting Cyclotron Laboratory (NSCL). We will discuss our new experimental setup which allows us to use full kinematics employing the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA) to detect the γ-rays following the de-excitation of excited states of the reaction products and the Low Energy Neutron Detector Array (LENDA) to detect the recoiling neutrons. The S800 was used for identification of the 24Si recoils. As a proof of principle to show the feasibility of this concept the Q-value spectrum of 22Mg(d,n)23Al is reconstructed.
Dellmann, Sophia Florence ; Reifarth, René ; Weigand, Mario ; Eberhardt, Klaus ; Garg, Ruchi ; Geppert, Christopher ; Heftrich, Tanja ; Kurtulgil, Cem Deniz ; Lederer-Woods, Claudia
The determination of astrophysically relevant neutron-induced cross sections is particularly difficult when the involved isotopes are radioactive or the cross sections are very small. Activation experiments at reactors offer the possibility to overcome these limitations with high neutron fluxes. The flux determination is typically based on the activation of two monitors with known cross sections to separate the different flux components. The usually applied cadmium difference method allows a distinction between the thermal and the epithermal part. By a combination of two linear functions representing both monitors the neutron flux components can be determined. However, if more than two monitors are used, the linear system of equations is overdetermined, which allows the identification of a probability distribution. In this proceeding, the feasibility and relevance of this method is demonstrated.
Brückner, Benjamin ; Erbacher, Philipp ; Göbel, Kathrin ; Heftrich, Tanja ; Khasawneh, Kafa al- ; Kurtulgil, Cem Deniz ; Langer, Christoph ; Nolte, Ralf ; Reich, Markus ; Reifarth, René ; Thomas, Benedikt ; Weigand, Mario ; Wiescher, Michael ; Volknandt, Meiko
The neutron activation method is well-suited to investigate neutron-capture cross sections relevant for the main s-process component. Neutrons can be produced via the 7Li(p,n) reaction with proton energies of 1912 keV at e.g. Van de Graaff accelerators, which results in a quasi-Maxwellian spectrum of neutrons corresponding to a temperature of kBT = 25 keV. However, the weak s-process takes place in massive stars at temperatures between 25 and 90 keV. Simulations using the PINO code [2] suggest that a Maxwellian spectrum for higher energies, e.g. kBT = 90 keV, can be approximated by a linear combination of different neutron spectra. To validate the PINO code at proton energies Ep ≠ 1912 keV, neutron time-of-flight measurements were carried out at the PTB Ion Accelerator Facility (PIAF) at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany.
Göbel, Kathrin ; Glorius, Jan ; Koloczek, Alexander ; Pignatari, Marco ; Reifarth, René ; Schach, René ; Sonnabend, Kerstin
We present a nucleosynthesis sensitivity study for the γ-process in a Supernova type II model within the NuGrid research platform. The simulations aimed at identifying the relevant local production and destruction rates for the p-nuclei of molybdenum and at determining the sensitivity of the final abundances to these rates. We show that local destruction rates strongly determine the abundance of 92Mo and 94Mo, and quantify the impact.
Barbagallo, Massimo ; Colonna, Nicola ; Altstadt, Sebastian ; Andrzejewski, Józef ; Audouin, Laurent ; Bécares, Vicente ; Bečvář, František ; Belloni, Fabio ; Berthoumieux, Eric ; Billowes, Jonathan ; Bosnar, Damir ; Brugger, Markus ; Calviani, Marco ; Calviño Tavares, Francisco ; Cano-Ott, Daniel ; Carrapiço, Carlos ; Cerutti, Francesco ; Chiaveri, Enrico ; Chin, Michael ; Cortés Rossell, Guillem Pere ; Cortés-Giraldo, Miguel Antonio ; Diakaki, Maria ; Domingo-Pardo, César ; Durán, Ignacio ; Dressler, Rugard ; Eleftheriadis, Christos ; Ferrari, Alfredo ; Fraval, Kevin ; Ganesan, Srinivasan ; García Ríos, Aczel Regino ; Giubrone, Giuseppe ; Gonçalves, Isabel Maria Ferro ; González Romero, Enrique Miguel ; Griesmayer, Erich ; Guerrero Sánchez, Carlos ; Gunsing, Frank ; Hernández Prieto, Álvaro ; Jenkins, David ; Jericha, Erwin ; Kadi, Yacine ; Käppeler, Franz ; Karadimos, Dimitri ; Kivel, Nikolay ; Koehler, Paul ; Krtička, Milan ; Kroll, Jiří ; Lampoudis, Christos ; Langer, Christoph ; Leal Cidoncha, Esther ; Lederer, Claudia ; Leeb, Helmut ; Leong, Lou Sai ; Losito, Roberto ; Manousos, Athanasios ; Marganiec, Justyna ; Martı́nez, Trinitario ; Massimi, Cristian ; Mastinu, Pierfrancesco ; Mastromarco, Mario ; Mendoza Cembranos, Emilio ; Mengoni, Alberto ; Milazzo, Paolo Maria ; Mingrone, Federica ; Mirea, Mihail ; Mondalaers, Willy ; Paradela Dobarro, Carlos ; Pavlik, Andreas ; Perkowski, Jarosław ; Plompen, Arjan J. M. ; Praena, Javier ; Quesada Molina, José Manuel ; Rauscher, Thomas ; Reifarth, René ; Riego Pérez, Albert ; Rubbia, Carlo ; Sabaté-Gilarte, Marta ; Sarmento, Raul ; Saxena, Alok ; Schillebeeckx, Peter ; Schmidt, Stefan ; Schumann, Dorothea ; Tagliente, Giuseppe ; Taı́n Enríquez, José Luis ; Tarrío Vilas, Diego ; Tassan-Got, Laurent ; Tsinganis, Andrea ; Valenta, Stanislav ; Vannini, Gianni ; Variale, Vincenzo ; Vaz, Pedro ; Ventura, Alberto ; Vermeulen, Mark J. ; Vlachoudis, Vasilis ; Vlastou, Rosa ; Wallner, Anton ; Ware, Timothy ; Weigand, Mario ; Weiß, Christina ; Wright, Tobias ; Žugec, Petar
The n_TOF facility operates at CERN with the aim of addressing the request of high accuracy nuclear data for advanced nuclear energy systems as well as for nuclear astrophysics. Thanks to the features of the neutron beam, important results have been obtained on neutron induced fission and capture cross sections of U, Pu and minor actinides. Recently the construction of another beam line has started; the new line will be complementary to the first one, allowing to further extend the experimental program foreseen for next measurement campaigns.
Dietz, Mirco ; Lederer-Woods, Claudia ; Aberle, Oliver ; Andrzejewski, Józef ; Audouin, Laurent ; Bacak, Michael ; Balibrea Correa, Javier ; Barbagallo, Massimo ; Bečvář, František ; Berthoumieux, Eric ; Billowes, Jonathan ; Bosnar, Damir ; Brown, Adam ; Caamaño, Manuel ; Calviño Tavares, Francisco ; Calviani, Marco ; Cano-Ott, Daniel ; Cardella, Roberto ; Casanovas Hoste, Adrià ; Cerutti, Francesco ; Chen, Yonghao ; Chiaveri, Enrico ; Colonna, Nicola ; Cortés Rossell, Guillem Pere ; Cortés-Giraldo, Miguel Antonio ; Cosentino, Luigi ; Damone, Lucia Anna ; Diakaki, Maria ; Domingo-Pardo, César ; Dressler, Rugard ; Dupont, Emmeric ; Durán, Ignacio ; Fernández Domínguez, Beatriz ; Ferrari, Alfredo ; Ferreira, Pedro G. ; Finocchiaro, Paolo ; Furman, Valter ; Göbel, Kathrin ; García Ríos, Aczel Regino ; Garg, Ruchi ; Gawlik, Aleksandra ; Gilardoni, Simone ; Glodariu, Tudor ; Gonçalves, Isabel Maria Ferro ; González Romero, Enrique Miguel ; Griesmayer, Erich ; Guerrero Sánchez, Carlos ; Gunsing, Frank ; Harada, Hideo ; Heinitz, Stephan ; Heyse, Jan ; Jenkins, David ; Jericha, Erwin ; Käppeler, Franz ; Kadi, Yacine ; Kahl, David ; Kalamara, Antigoni ; Kavrigin, Pavel ; Kimura, Atsushi ; Kivel, Nikolay ; Kokkoris, Michael ; Krtička, Milan ; Kurtulgil, Cem Deniz ; Leal Cidoncha, Esther ; Leeb, Helmut ; Lerendegui-Marco, Jorge ; Lo Meo, Sergio ; Lonsdale, Sarah Jane ; Macina, Daniela ; Marganiec, Justyna ; Martı́nez, Trinitario ; Masi, Alessandro ; Massimi, Cristian ; Mastinu, Pierfrancesco ; Mastromarco, Mario ; Maugeri, Emilio Andrea ; Mazzone, Annamaria ; Mendoza Cembranos, Emilio ; Mengoni, Alberto ; Milazzo, Paolo Maria ; Mingrone, Federica ; Musumarra, Agatino ; Negret, Alexandru ; Nolte, Ralf ; Oprea, Andreea ; Patronis, Nikolas ; Pavlik, Andreas ; Perkowski, Jarosław ; Porras Sánchez, José Ignacio ; Praena, Javier ; Quesada Molina, José Manuel ; Radeck, Désirée ; Rauscher, Thomas ; Reifarth, René ; Rubbia, Carlo ; Ryan, James A. ; Sabateé-Gilarte, Marta ; Saxena, Alok ; Schillebeeckx, Peter ; Schumann, Dorothea ; Sedyshev, Pavel V. ; Smith, Alastair Gavin ; Sosnin, Nikolay V. ; Stamatopoulos, Athanasios ; Tagliente, Giuseppe ; Taı́n Enríquez, Jose Luis ; Tarifeño-Saldivia, Ariel ; Tassan-Got, Laurent ; Valenta, Stanislav ; Vannini, Gianni ; Variale, Vincenzo ; Vaz, Pedro ; Ventura, Alberto ; Vlachoudis, Vasilis ; Vlastou, Rosa ; Wallner, Anton ; Warren, Stephen J. ; Weiß, Christina ; Woods, Philip John ; Wright, Tobias ; Žugec, Petar
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, γ) cross section has an important influence on production of isotopes between Ge and Zr during s-process in massive stars and therefore experimental data are urgently required. 72Ge(n, γ) was measured at the neutron time-of-flight facility n_TOF (CERN) for the first time at stellar energies. The measurement was performed using an enriched 72GeO2 sample at a flight path of 185m with a set of liquid scintillation detectors (C6D6). The motivation, experiment and current status of the data analysis are reported.
Casanovas Hoste, Adrià ; Domingo-Pardo, César ; Guerrero Sánchez, Carlos ; Lerendegui-Marco, Jorge ; Calviño Tavares, Francisco ; Tarifeño-Saldivia, Ariel ; Dressler, Rugard ; Heinitz, Stephan ; Kivel, Nikolay ; Quesada Molina, José Manuel ; Schumann, Dorothea ; Aberle, Oliver ; Alcayne, Victor ; Andrzejewski, Józef ; Audouin, Laurent ; Bécares, Vicente ; Bacak, Michael ; Barbagallo, Massimo ; Bečvář, František ; Bellia, Giorgio ; Berthoumieux, Eric ; Billowes, Jonathan ; Bosnar, Damir ; Brown, Adam ; Busso, Maurizio ; Caamaño, Manuel ; Caballero Ontanaya, Luis ; Calviani, Marco ; Cano-Ott, Daniel ; Cerutti, Francesco ; Chen, Yonghao ; Chiaveri, Enrico ; Colonna, Nicola ; Cortés Rossell, Guillem Pere ; Cortés-Giraldo, Miguel Antonio ; Cosentino, Luigi ; Cristallo, Sergio ; Damone, Lucia Anna ; Diakaki, Maria ; Dietz, Mirco ; Dupont, Emmeric ; Durán, Ignacio ; Eleme, Zinovia ; Fernández Domínguez, Beatriz ; Ferrari, Alfredo ; Ferreira, Pedro G. ; Finocchiaro, Paolo ; Furman, Valter ; Göbel, Kathrin ; Gawlik, Aleksandra ; Gilardoni, Simone ; Glodariu, Tudor ; Gonçalves, Isabel Maria Ferro ; González Romero, Enrique Miguel ; Gunsing, Frank ; Heyse, Jan ; Jenkins, David ; Käppeler, Franz ; Kadi, Yacine ; Katabuchi, Tatsuya ; Kimura, Atsushi ; Kokkoris, Michael ; Kopatch, Yuri N. ; Krtička, Milan ; Kurtulgil, Cem Deniz ; Ladarescu, Ion ; Lederer-Woods, Claudia ; Lo Meo, Sergio ; Lonsdale, Sarah Jane ; Macina, Daniela ; Martı́nez, Trinitario ; Masi, Alessandro ; Massimi, Cristian ; Mastinu, Pierfrancesco ; Mastromarco, Mario ; Matteucci, Francesca ; Maugeri, Emilio Andrea ; Mazzone, Annamaria ; Mendoza Cembranos, Emilio ; Mengoni, Alberto ; Michalopoulou, Veatriki ; Milazzo, Paolo Maria ; Mingrone, Federica ; Musumarra, Agatino ; Negret, Alexandru ; Nolte, Ralf ; Ogállar Ruiz, Francisco ; Oprea, Andreea ; Patronis, Nikolas ; Pavlik, Andreas ; Perkowski, Jarosław ; Piersanti, Luciano ; Porras Sánchez, José Ignacio ; Praena, Javier ; Radeck, Désirée ; Ramos Doval, Diego ; Rauscher, Thomas ; Reifarth, René ; Rochman, Dimitri ; Sabaté-Gilarte, Marta ; Saxena, Alok ; Schillebeeckx, Peter ; Simone, Saverio ; Smith, Alastair Gavin ; Sosnin, Nikolay V. ; Stamatopoulos, Athanasios ; Tagliente, Giuseppe ; Taı́n Enríquez, José Luis ; Talip, T. ; Tassan-Got, Laurent ; Tsinganis, Andrea ; Ulrich, Jiri ; Valenta, Stanislav ; Vannini, Gianni ; Variale, Vincenzo ; Vaz, Pedro ; Ventura, Alberto ; Vlachoudis, Vasilis ; Vlastou, Rosa ; Wallner, Anton ; Woods, Philip John ; Wright, Tobias ; Žugec, Petar ; Köster, Ulrich
The neutron capture cross section of some unstable nuclei is especially relevant for s-process nucleosynthesis studies. This magnitude is crucial to determine the local abundance pattern, which can yield valuable information of the s-process stellar environment. In this work we describe the neutron capture (n,γ) measurement on two of these nuclei of interest, 204Tl and 171Tm, from target production to the final measurement, performed successfully at the n_TOF facility at CERN in 2014 and 2015. Preliminary results on the ongoing experimental data analysis will also be shown. These results include the first ever experimental observation of capture resonances for these two nuclei.