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1. Corrigendum: 'Measurement of 73Ge(n,γ) cross sections and implications for stellar nucleosynthesis' [Phys. Lett. B 790 (2019) 458–465]

Author

C. Lederer-Woods, U. Battino, P. Ferreira, A. Gawlik, C. Guerrero, F. Gunsing, S. Heinitz, J. Lerendegui-Marco, A. Mengoni, R. Reifarth, A. Tattersall, S. Valenta, C. Weiss, O. Aberle, J. Andrzejewski, L. Audouin, V. Bécares, M. Bacak, J. Balibrea, M. Barbagallo, S. Barros, F. Bečvář, C. Beinrucker, F. Belloni, E. Berthoumieux, J. Billowes, D. Bosnar, M. Brugger, M. Caamaño, F. Calviño, M. Calviani, D. Cano-Ott, F. Cerutti, E. Chiaveri, N. Colonna, G. Cortés, M.A. Cortés-Giraldo, L. Cosentino, L.A. Damone, K. Deo, M. Diakaki, M. Dietz, C. Domingo-Pardo, R. Dressler, E. Dupont, I. Durán, B. Fernández-Domínguez, A. Ferrari, P. Finocchiaro, R.J.W. Frost, V. Furman, K. Göbel, A.R. García, I. Gheorghe, T. Glodariu, I.F. Gonçalves, E. González-Romero, A. Goverdovski, E. Griesmayer, H. Harada, T. Heftrich, A. Hernández-Prieto, J. Heyse, D.G. Jenkins, E. Jericha, F. Käppeler, Y. Kadi, T. Katabuchi, P. Kavrigin, V. Ketlerov, V. Khryachkov, A. Kimura, N. Kivel, I. Knapova, M. Kokkoris, M. Krtička, E. Leal-Cidoncha, H. Leeb, M. Licata, S. Lo Meo, R. Losito, D. Macina, J. Marganiec, T. Martínez, C. Massimi, P. Mastinu, M. Mastromarco, F. Matteucci, E. Mendoza, P.M. Milazzo, F. Mingrone, M. Mirea, S. Montesano, A. Musumarra, R. Nolte, F.R. Palomo-Pinto, C. Paradela, N. Patronis, A. Pavlik, J. Perkowski, J.I. Porras, J. Praena, J.M. Quesada, T. Rauscher, A. Riego-Perez, M. Robles, C. Rubbia, J.A. Ryan, M. Sabaté-Gilarte, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, P. Sedyshev, A.G. Smith, A. Stamatopoulos, S.V. Suryanarayana, G. Tagliente, J.L. Tain, A. Tarifeño-Saldivia, L. Tassan-Got, A. Tsinganis, G. Vannini, V. Variale, P. Vaz, A. Ventura, V. Vlachoudis, R. Vlastou, A. Wallner, S. Warren, M. Weigand, T. Wright, and P. Žugec

Subjects
Physics, QC1-999
Published
2023
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2. Quasi-free neutron and proton knockout reactions from light nuclei in a wide neutron-to-proton asymmetry range

Author

M. Holl, V. Panin, H. Alvarez-Pol, L. Atar, T. Aumann, S. Beceiro-Novo, J. Benlliure, C.A. Bertulani, J.M. Boillos, K. Boretzky, M. Caamaño, C. Caesar, E. Casarejos, W. Catford, J. Cederkall, L. Chulkov, D. Cortina-Gil, E. Cravo, I. Dillmann, P. Díaz Fernández, Z. Elekes, J. Enders, L.M. Fraile, D. Galaviz Redondo, R. Gernhäuser, P. Golubev, T. Heftrich, M. Heil, M. Heine, A. Heinz, A. Henriques, H.T. Johansson, B. Jonson, N. Kalantar-Nayestanaki, R. Kanungo, A. Kelic-Heil, T. Kröll, N. Kurz, C. Langer, T. Le Bleis, S. Lindberg, J. Machado, E. Nacher, M.A. Najafi, T. Nilsson, C. Nociforo, S. Paschalis, M. Petri, R. Reifarth, G. Ribeiro, C. Rigollet, D.M. Rossi, D. Savran, H. Scheit, H. Simon, O. Sorlin, I. Syndikus, O. Tengblad, Y. Togano, M. Vandebrouck, P. Velho, F. Wamers, H. Weick, C. Wheldon, G.L. Wilson, J.S. Winfield, P. Woods, M. Zhukov, and K. Zuber

Subjects
Physics, QC1-999
Abstract

The quasi-free scattering reactions 11C(p,2p) and 10,11,12C(p,pn) have been studied in inverse kinematics at beam energies of 300–400 MeV/u at the R3B-LAND setup. The outgoing proton-proton and proton-neutron pairs were detected in coincidence with the reaction fragments in kinematically complete measurements. The efficiency to detect these pairs has been obtained from GEANT4 simulations which were tested using the 12C(p,2p) and 12C(p,pn) reactions. Experimental cross sections and momentum distributions have been obtained and compared to DWIA calculations based on eikonal theory. The new results reported here are combined with previously published cross sections for quasi-free scattering from oxygen and nitrogen isotopes and together they enable a systematic study of the reduction of single-particle strength compared to predictions of the shell model over a wide neutron-to-proton asymmetry range. The combined reduction factors show a weak or no dependence on isospin asymmetry, in contrast to the strong dependency reported in nucleon-removal reactions induced by nuclear targets at lower energies. However, the reduction factors for (p,2p) are found to be 'significantly smaller than for (p,pn) reactions for all investigated nuclei. Keywords: Quasi-free scattering, Inverse kinematics, Shell model, Spectroscopic factors

Published
2019
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3. Measurement of 73Ge(n,γ) cross sections and implications for stellar nucleosynthesis

Author

C. Lederer-Woods, U. Battino, P. Ferreira, A. Gawlik, C. Guerrero, F. Gunsing, S. Heinitz, J. Lerendegui-Marco, A. Mengoni, R. Reifarth, A. Tattersall, S. Valenta, C. Weiss, O. Aberle, J. Andrzejewski, L. Audouin, V. Bécares, M. Bacak, J. Balibrea, M. Barbagallo, S. Barros, F. Bečvář, C. Beinrucker, F. Belloni, E. Berthoumieux, J. Billowes, D. Bosnar, M. Brugger, M. Caamaño, F. Calviño, M. Calviani, D. Cano-Ott, F. Cerutti, E. Chiaveri, N. Colonna, G. Cortés, M.A. Cortés-Giraldo, L. Cosentino, L.A. Damone, K. Deo, M. Diakaki, M. Dietz, C. Domingo-Pardo, R. Dressler, E. Dupont, I. Durán, B. Fernández-Domínguez, A. Ferrari, P. Finocchiaro, R.J.W. Frost, V. Furman, K. Göbel, A.R. García, I. Gheorghe, T. Glodariu, I.F. Gonçalves, E. González-Romero, A. Goverdovski, E. Griesmayer, H. Harada, T. Heftrich, A. Hernández-Prieto, J. Heyse, D.G. Jenkins, E. Jericha, F. Käppeler, Y. Kadi, T. Katabuchi, P. Kavrigin, V. Ketlerov, V. Khryachkov, A. Kimura, N. Kivel, I. Knapova, M. Kokkoris, M. Krtička, E. Leal-Cidoncha, H. Leeb, M. Licata, S. Lo Meo, R. Losito, D. Macina, J. Marganiec, T. Martínez, C. Massimi, P. Mastinu, M. Mastromarco, F. Matteucci, E. Mendoza, P.M. Milazzo, F. Mingrone, M. Mirea, S. Montesano, A. Musumarra, R. Nolte, F.R. Palomo-Pinto, C. Paradela, N. Patronis, A. Pavlik, J. Perkowski, J.I. Porras, J. Praena, J.M. Quesada, T. Rauscher, A. Riego-Perez, M. Robles, C. Rubbia, J.A. Ryan, M. Sabaté-Gilarte, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, P. Sedyshev, A.G. Smith, A. Stamatopoulos, S.V. Suryanarayana, G. Tagliente, J.L. Tain, A. Tarifeño-Saldivia, L. Tassan-Got, A. Tsinganis, G. Vannini, V. Variale, P. Vaz, A. Ventura, V. Vlachoudis, R. Vlastou, A. Wallner, S. Warren, M. Weigand, T. Wright, and P. Žugec

Subjects
Physics, QC1-999
Abstract

73Ge(n,γ) 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 cross section at kT=30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of 73Ge produced in stars, which would explain the low isotopic abundance of 73Ge in the solar system. Keywords: Nucleosynthesis, Neutron capture, s process, Germanium, n_TOF

Published
2019
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4. New test of modulated electron capture decay of hydrogen-like 142Pm ions: Precision measurement of purely exponential decay

Author

F.C. Ozturk, B. Akkus, D. Atanasov, H. Beyer, F. Bosch, D. Boutin, C. Brandau, P. Bühler, R.B. Cakirli, R.J. Chen, W.D. Chen, X.C. Chen, I. Dillmann, C. Dimopoulou, W. Enders, H.G. Essel, T. Faestermann, O. Forstner, B.S. Gao, H. Geissel, R. Gernhäuser, R.E. Grisenti, A. Gumberidze, S. Hagmann, T. Heftrich, M. Heil, M.O. Herdrich, P.-M. Hillenbrand, T. Izumikawa, P. Kienle, C. Klaushofer, C. Kleffner, C. Kozhuharov, R.K. Knöbel, O. Kovalenko, S. Kreim, T. Kühl, C. Lederer-Woods, M. Lestinsky, S.A. Litvinov, Yu.A. Litvinov, Z. Liu, X.W. Ma, L. Maier, B. Mei, H. Miura, I. Mukha, A. Najafi, D. Nagae, T. Nishimura, C. Nociforo, F. Nolden, T. Ohtsubo, Y. Oktem, S. Omika, A. Ozawa, N. Petridis, J. Piotrowski, R. Reifarth, J. Rossbach, R. Sánchez, M.S. Sanjari, C. Scheidenberger, R.S. Sidhu, H. Simon, U. Spillmann, M. Steck, Th. Stöhlker, B.H. Sun, L.A. Susam, F. Suzaki, T. Suzuki, S.Yu. Torilov, C. Trageser, M. Trassinelli, S. Trotsenko, X.L. Tu, P.M. Walker, M. Wang, G. Weber, H. Weick, N. Winckler, D.F.A. Winters, P.J. Woods, T. Yamaguchi, X.D. Xu, X.L. Yan, J.C. Yang, Y.J. Yuan, Y.H. Zhang, and X.H. Zhou

Subjects
Physics, QC1-999
Abstract

An experiment addressing electron capture (EC) decay of hydrogen-like Pm60+142 ions has been conducted at the experimental storage ring (ESR) at GSI. The decay appears to be purely exponential and no modulations were observed. Decay times for about 9000 individual EC decays have been measured by applying the single-ion decay spectroscopy method. Both visually and automatically analysed data can be described by a single exponential decay with decay constants of 0.0126(7)s−1 for automatic analysis and 0.0141(7)s−1 for manual analysis. If a modulation superimposed on the exponential decay curve is assumed, the best fit gives a modulation amplitude of merely 0.019(15), which is compatible with zero and by 4.9 standard deviations smaller than in the original observation which had an amplitude of 0.23(4). Keywords: Two body weak decay, Orbital electron capture, Single particle decay spectroscopy, Heavy ion storage ring

Published
2019
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5. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment

Author

A. Ruiz, T. Timke, A. van de Sande, T. Heftrich, R. Novotny, and T. Austin

Subjects
Computer applications to medicine. Medical informatics, R858-859.7, Science (General), Q1-390
Abstract

This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. Keywords: Supercritical water reactor, SCWR, General corrosion, Austenitic stainless steel, Microstructural analysis

Published
2016
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7. Gamma intensities for the β-decay of 97Zr

Author

M. Weigand, S.F. Dellmann, B. Brückner, P. Erbacher, K. Eberhardt, C. Geppert, T. Heftrich, T. Kisselbach, D. Kurtulgil, M. Reich, R. Reifarth, and M. Volknandt

Subjects
Nuclear and High Energy Physics, Instrumentation
Published
2023

8. Preparation and characterization of 33S samples for 33S(n,α)30Si cross-section measurements at the n_TOF facility at CERN

Author

J. Praena, F.J. Ferrer, W. Vollenberg, M. Sabaté-Gilarte, B. Fernández, J. García-López, I. Porras, J.M. Quesada, S. Altstadt, J. Andrzejewski, L. Audouin, V. Bécares, M. Barbagallo, F. Bečvář, F. Belloni, E. Berthoumieux, J. Billowes, V. Boccone, D. Bosnar, M. Brugger, F. Calviño, M. Calviani, D. Cano-Ott, C. Carrapiço, F. Cerutti, E. Chiaveri, M. Chin, N. Colonna, G. Cortés, M.A. Cortés-Giraldo, M. Diakaki, M. Dietz, C. Domingo-Pardo, R. Dressler, I. Durán, C. Eleftheriadis, A. Ferrari, K. Fraval, V. Furman, K. Göbel, M.B. Gómez-Hornillos, S. Ganesan, A.R. García, G. Giubrone, I.F. Gonçalves, E. González-Romero, A. Goverdovski, E. Griesmayer, C. Guerrero, F. Gunsing, T. Heftrich, A. Hernández-Prieto, J. Heyse, D.G. Jenkins, E. Jericha, F. Käppeler, Y. Kadi, D. Karadimos, T. Katabuchi, V. Ketlerov, V. Khryachkov, N. Kivel, P. Koehler, M. Kokkoris, J. Kroll, M. Krtička, C. Lampoudis, C. Langer, E. Leal-Cidoncha, C. Lederer, H. Leeb, L.S. Leong, J. Lerendegui-Marco, R. Losito, A. Mallick, A. Manousos, J. Marganiec, T. Martínez, C. Massimi, P. Mastinu, M. Mastromarco, E. Mendoza, A. Mengoni, P.M. Milazzo, F. Mingrone, M. Mirea, W. Mondelaers, C. Paradela, A. Pavlik, J. Perkowski, A.J.M. Plompen, T. Rauscher, R. Reifarth, A. Riego-Perez, M. Robles, C. Rubbia, J.A. Ryan, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, P. Sedyshev, G. Tagliente, J.L. Tain, A. Tarifeño-Saldivia, D. Tarrío, L. Tassan-Got, A. Tsinganis, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, M.J. Vermeulen, V. Vlachoudis, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Weiss, T. Wright, and P. Žugec

Subjects
Physics, Nuclear and High Energy Physics, Thin layers, 010308 nuclear & particles physics, Analytical chemistry, chemistry.chemical_element, Rutherford backscattering spectrometry, 7. Clean energy, 01 natural sciences, Copper, Kapton, Chromium, chemistry, 0103 physical sciences, Sublimation (phase transition), Neutron, 010306 general physics, Instrumentation, Titanium
Abstract

Thin 33S samples for the study of the 33S(n, α)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.

Published
2018

9. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment

Author

T. Heftrich, A. van de Sande, A. Ruiz, T. Austin, T. Timke, and R. Novotny

Subjects
Materials science, Austenitic stainless steel, 020209 energy, Oxide, 02 engineering and technology, engineering.material, lcsh:Computer applications to medicine. Medical informatics, SCWR, Corrosion, chemistry.chemical_compound, 0202 electrical engineering, electronic engineering, information engineering, General corrosion, lcsh:Science (General), Data Article, Austenite, Multidisciplinary, Microstructural analysis, Metallurgy, Intergranular corrosion, 021001 nanoscience & nanotechnology, Supercritical water reactor, Supercritical fluid, chemistry, 13. Climate action, engineering, lcsh:R858-859.7, Grain boundary, 0210 nano-technology, Layer (electronics), lcsh:Q1-390
Abstract

This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. Keywords: Supercritical water reactor, SCWR, General corrosion, Austenitic stainless steel, Microstructural analysis

Published
2016
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10. Nuclear astrophysics with radioactive ions at FAIR

Author

R Reifarth, S Altstadt, K Göbel, T Heftrich, M Heil, A Koloczek, C Langer, R Plag, M Pohl, K Sonnabend, M Weigand, T Adachi, F Aksouh, J Al-Khalili, M AlGarawi, S AlGhamdi, G Alkhazov, N Alkhomashi, H Alvarez-Pol, R Alvarez-Rodriguez, V Andreev, B Andrei, L Atar, T Aumann, V Avdeichikov, C Bacri, S Bagchi, C Barbieri, S Beceiro, C Beck, C Beinrucker, G Belier, D Bemmerer, M Bendel, J Benlliure, G Benzoni, R Berjillos, D Bertini, C Bertulani, S Bishop, N Blasi, T Bloch, Y Blumenfeld, A Bonaccorso, K Boretzky, A Botvina, A Boudard, P Boutachkov, I Boztosun, A Bracco, S Brambilla, J Briz Monago, M Caamano, C Caesar, F Camera, E Casarejos, W Catford, J Cederkall, B Cederwall, M Chartier, A Chatillon, M Cherciu, L Chulkov, P Coleman-Smith, D Cortina-Gil, F Crespi, R Crespo, J Cresswell, M Csatlós, F Déchery, B Davids, T Davinson, V Derya, P Detistov, P Diaz Fernandez, D DiJulio, S Dmitry, D Doré, J Dueñas, E Dupont, P Egelhof, I Egorova, Z Elekes, J Enders, J Endres, S Ershov, O Ershova, B Fernandez-Dominguez, A Fetisov, E Fiori, A Fomichev, M Fonseca, L Fraile, M Freer, J Friese, M G. Borge, D Galaviz Redondo, S Gannon, U Garg, I Gasparic, L Gasques, B Gastineau, H Geissel, R Gernhäuser, T Ghosh, M Gilbert, J Glorius, P Golubev, A Gorshkov, A Gourishetty, L Grigorenko, J Gulyas, M Haiduc, F Hammache, M Harakeh, M Hass, M Heine, A Hennig, A Henriques, R Herzberg, M Holl, A Ignatov, A Ignatyuk, S Ilieva, M Ivanov, N Iwasa, B Jakobsson, H Johansson, B Jonson, P Joshi, A Junghans, B Jurado, G Körner, N Kalantar, R Kanungo, A Kelic-Heil, K Kezzar, E Khan, A Khanzadeev, O Kiselev, M Kogimtzis, D Körper, S Kräckmann, T Kröll, R Krücken, A Krasznahorkay, J Kratz, D Kresan, T Krings, A Krumbholz, S Krupko, R Kulessa, S Kumar, N Kurz, E Kuzmin, M Labiche, K Langanke, I Lazarus, T Le Bleis, C Lederer, A Lemasson, R Lemmon, V Liberati, Y Litvinov, B Löher, J Lopez Herraiz, G Münzenberg, J Machado, E Maev, K Mahata, D Mancusi, J Marganiec, M Martinez Perez, V Marusov, D Mengoni, B Million, V Morcelle, O Moreno, A Movsesyan, E Nacher, M Najafi, T Nakamura, F Naqvi, E Nikolski, T Nilsson, C Nociforo, P Nolan, B Novatsky, G Nyman, A Ornelas, R Palit, S Pandit, V Panin, C Paradela, V Parkar, S Paschalis, P Pawłowski, A Perea, J Pereira, C Petrache, M Petri, S Pickstone, N Pietralla, S Pietri, Y Pivovarov, P Potlog, A Prokofiev, G Rastrepina, T Rauscher, G Ribeiro, M Ricciardi, A Richter, C Rigollet, K Riisager, A Rios, C Ritter, T Rodriguez Frutos, J Rodriguez Vignote, M Röder, C Romig, D Rossi, P Roussel-Chomaz, P Rout, S Roy, P Söderström, M Saha Sarkar, S Sakuta, M Salsac, J Sampson, J Sanchez, del Rio Saez, J Sanchez Rosado, S Sanjari, P Sarriguren, A Sauerwein, D Savran, C Scheidenberger, H Scheit, S Schmidt, C Schmitt, L Schnorrenberger, P Schrock, R Schwengner, D Seddon, B Sherrill, A Shrivastava, S Sidorchuk, J Silva, H Simon, E Simpson, P Singh, D Slobodan, D Sohler, M Spieker, D Stach, E Stan, M Stanoiu, S Stepantsov, P Stevenson, F Strieder, L Stuhl, T Suda, K Sümmerer, B Streicher, J Taieb, M Takechi, I Tanihata, J Taylor, O Tengblad, G Ter-Akopian, S Terashima, P Teubig, R Thies, M Thoennessen, T Thomas, J Thornhill, G Thungstrom, J Timar, Y Togano, U Tomohiro, T Tornyi, J Tostevin, C Townsley, W Trautmann, T Trivedi, S Typel, E Uberseder, J Udias, T Uesaka, L Uvarov, Z Vajta, P Velho, V Vikhrov, M Volknandt, V Volkov, P von Neumann-Cosel, M von Schmid, A Wagner, F Wamers, H Weick, D Wells, L Westerberg, O Wieland, M Wiescher, C Wimmer, K Wimmer, J S Winfield, M Winkel, P Woods, R Wyss, D Yakorev, M Yavor, J Zamora Cardona, I Zartova, T Zerguerras, M Zgura, A Zhdanov, M Zhukov, M Zieblinski, A Zilges, K Zuber, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Helmholtz International Center for FAIR, German Research Foundation, Helmholtz Association, SCOAP, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
History, Astrophysics and Astronomy, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 01 natural sciences, Education, Nuclear physics, Subatomär fysik, Nucleosynthesis, 0103 physical sciences, Subatomic Physics, Nuclear astrophysics, Fysik, Neutron, Nuclear Physics - Experiment, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Radionuclide, Isotope, rp-process, Computer Science Applications, FAIR nuclear astrophysics radioactive ion beams, Valley of stability, r-process nucleosynthesis, weak-interaction rates, s-process, stars, supernovae, light, Physical Sciences, Facility for Antiproton and Ion Research, Física nuclear, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], astro-ph.IM
Abstract

R. Reifarth et al: ; 12 págs.; 9 figs.; Open Access funded by Creative Commons Atribution Licence 3.0 ; Nuclear Physics in Astrophysics VI (NPA6), The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process ow and r-process -decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will oer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes., This project was supported by the HGF Young Investigators Project VH-NG-327, EMMI, H4F, HGS-HIRe, JINA, NAVI, DFG and ATHENA.

Published
2016

11. THE UNUSUAL SPECTRAL ENERGY DISTRIBUTION OF LBQS 0102-2713

Author

T. Heftrich, Th. Boller, K. Linguri, and M. Weigand

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Faint Object Spectrograph, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Spectral line, Luminosity, Photometry (astronomy), Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ROSAT, Astrophysics::Solar and Stellar Astrophysics, Spectral energy distribution, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We have studied the SED of the quasar LBQS 0102-2713. The available multiwavelength data are one optical spectrum between 3200 and 7400 A, 7 HST FOS spectra between 1700 and 2300 A, one GALEX NUV flux density and a K_S magnitude obtained from NED, and 3 public ROSAT PSPC pointed observations in the 0.1$-$2.4 keV energy band. The alpha_ox values obtained are -2.3 and -2.2, respectively, comparable to BAL quasars. The ROSAT photon index is 6.0+-1.3. The 2500 A luminosity density is about a factor of 10 higher compared to the mean of the most luminous SDSS quasars. We argue that the object might be indicative for a new class of quasars with an unusual combination in their UV-, X-ray, and N_H properties., Comment: 16 pages, 8 figures, accepted by ApJ

Published
2009

12. The Extreme SED of the Quasar [HB89] 0102–272

Author

Th. Boller, T. Heftrich, Jéro^me Rodriguez, and Phillippe Ferrando

Subjects
Physics, X-ray spectroscopy, Photon, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Luminosity, Orders of magnitude (time), ROSAT, Spectral energy distribution, Astrophysics::Galaxy Astrophysics
Abstract

We have studied the spectral energy distribution of the quasar [HB89] 0102–272. The available multiwavelength data in the observers frame are one optical spectrum between 3000 and 8000 A, 7 HST FOS spectra between 1600 and 2300 A, and 3 ROSAT PSPC pointed observations in the 0.1–2.4 keV energy band. The αox value obtained from the HST FOS spectra and the optical spectrum is extreme with −2.2 and −2.1, respectively and is one of the steepest values reported so far. The 2500 A luminosity density is about 5 orders of magnitude larger than the 2 keV flux density. The object is as bright as the brightest SDSS quasars but X‐ray weak at 2 keV. We compare our αox findings with the mean quasar SED from [14] and conclude that [HB89] 0102–292 is unusual for any type of quasar SED’s. In addition an extreme steep soft X‐ray photon index of Γ = (6.0±1.3) has been detected, the steepest value reported so far. When fitting the X‐ray and optical and HST UV data simultaneously with a simple black body model an extreme disc...

Published
2009

13. XMM-Newton, Swift and ROSAT observations of LBQS 0102-2713

Author

Th. Boller, T. Heftrich, and Patricia Schady

Subjects
Physics, Brightness, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Luminosity, Space and Planetary Science, ROSAT, Absorption (logic), Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Line (formation), Dimensionless quantity
Abstract

We have analyzed the first XMM-Newton, Swift and archival ROSAT PSPC observations of the quasar LBQS 0102-2713.The object was selected from the ROSAT archive as being notable due to the steep soft X-ray photon index and due to the UV brightness based on HST and optical spectroscopic observations. The first XMM-Newton observations carried out in December 2009 and the first Swift observations from 2010 have confirmed the steepness of the soft X-ray photon index, which ranges between 3.35 and 4.41 for the different XMM-Newton and ROSAT detectors, the UV brightness of the source and the absence of significant absorption by neutral hydrogen. The new data allow a combined spectral fitting to the Swift UVOT and the XMM-Newton/ROSAT data which results in a huge luminosity of (6.2+-0.2)x10^47 erg s^(-1) and alpha_ox values ranging between (-1.87+-0.11) and (-2.11+-0.12). The nature of the soft X-ray emission can be explained as local Comptonized emission of the UV disc photons in the pseudo-Newtonian potential. The black hole mass is estimated from the Mg II line and translates into an Eddington ratio of L/L_edd = 18(+33)(-12). For the dimensionless electron temperature of the plasma cloud theta = kT_e/ (m_e c^2) we derive an upper limit of about 10 keV., Comment: 5 pages, 3 figures, accepted for publication in ApJ Letters

14. Nuclear astrophysics at FRANZ.

Author

R Reifarth, S Dababneh, S Fiebiger, J Glorius, K Göbel, M Heil, P Hillmann, T Heftrich, C Langer, O Meusel, R Plag, S Schmidt, Z Slavkovská, D Veltum, M Weigand, C Wiesner, C Wolf, and A Zadeh

Published
2018
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17. Shedding Light on the Origin of ^{204}Pb, the Heaviest s-Process-Only Isotope in the Solar System.

Author

Casanovas-Hoste A, Domingo-Pardo C, Lerendegui-Marco J, Guerrero C, Tarifeño-Saldivia A, Krtička M, Pignatari M, Calviño F, Schumann D, Heinitz S, Dressler R, Köster U, Aberle O, Andrzejewski J, Audouin L, Bécares V, Bacak M, Balibrea-Correa J, Barbagallo M, Barros S, Bečvář F, Beinrucker C, Berthoumieux E, Billowes J, Bosnar D, Brugger M, Caamaño M, Calviani M, Cano-Ott D, Cardella R, Castelluccio DM, Cerutti F, Chen YH, Chiaveri E, Colonna N, Cortés G, Cortés-Giraldo MA, Cosentino L, Damone LA, Diakaki M, Dupont E, Durán I, Fernández-Domínguez B, Ferrari A, Ferreira P, Finocchiaro P, Furman V, Göbel K, García AR, Gawlik-Ramięga A, Glodariu T, Gonçalves IF, González-Romero E, Goverdovski A, Griesmayer E, Gunsing F, Harada H, Heftrich T, Heyse J, Jenkins DG, Jericha E, Käppeler F, Kadi Y, Katabuchi T, Kavrigin P, Ketlerov V, Khryachkov V, Kimura A, Kivel N, Kokkoris M, Leal-Cidoncha E, Lederer-Woods C, Leeb H, Lo Meo S, Lonsdale SJ, Losito R, Macina D, Marganiec J, Martínez T, Massimi C, Mastinu P, Mastromarco M, Matteucci F, Maugeri EA, Mendoza E, Mengoni A, Milazzo PM, Mingrone F, Mirea M, Montesano S, Musumarra A, Nolte R, Oprea A, Patronis N, Pavlik A, Perkowski J, Porras I, Praena J, Quesada JM, Rajeev K, Rauscher T, Reifarth R, Riego-Perez A, Romanets Y, Rout PC, Rubbia C, Ryan JA, Sabaté-Gilarte M, Saxena A, Schillebeeckx P, Schmidt S, Sedyshev P, Smith AG, Stamatopoulos A, Tagliente G, Tain JL, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Wallner A, Warren S, Weigand M, Weiss C, Wolf C, Woods PJ, Wright T, and Žugec P

Abstract

Asymptotic giant branch stars are responsible for the production of most of the heavy isotopes beyond Sr observed in the solar system. Among them, isotopes shielded from the r-process contribution by their stable isobars are defined as s-only nuclei. For a long time the abundance of ^{204}Pb, the heaviest s-only isotope, has been a topic of debate because state-of-the-art stellar models appeared to systematically underestimate its solar abundance. Besides the impact of uncertainties from stellar models and galactic chemical evolution simulations, this discrepancy was further obscured by rather divergent theoretical estimates for the neutron capture cross section of its radioactive precursor in the neutron-capture flow, ^{204}Tl (t_{1/2}=3.78  yr), and by the lack of experimental data on this reaction. We present the first ever neutron capture measurement on ^{204}Tl, conducted at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of ^{204}Tl produced at the Institute Laue Langevin high flux reactor. By complementing our new results with semiempirical calculations we obtained, at the s-process temperatures of kT≈8  keV and kT≈30  keV, Maxwellian-averaged cross sections (MACS) of 580(168) mb and 260(90) mb, respectively. These figures are about 3% lower and 20% higher than the corresponding values widely used in astrophysical calculations, which were based only on theoretical calculations. By using the new ^{204}Tl MACS, the uncertainty arising from the ^{204}Tl(n,γ) cross section on the s-process abundance of ^{204}Pb has been reduced from ∼30% down to +8%/-6%, and the s-process calculations are in agreement with the latest solar system abundance of ^{204}Pb reported by K. Lodders in 2021.

Published
2024
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18. 74 Ge( n , γ ) cross section below 70 keV measured at n_TOF CERN.

Author

Lederer-Woods C, Aberle O, Andrzejewski J, Audouin L, Bécares V, Bacak M, Balibrea J, Barbagallo M, Barros S, Battino U, Bečvář F, Beinrucker C, Berthoumieux E, Billowes J, Bosnar D, Brugger M, Caamaño M, Calviño F, Calviani M, Cano-Ott D, Cardella R, Casanovas A, Castelluccio DM, Cerutti F, Chen YH, Chiaveri E, Colonna N, Cortés G, Cortés-Giraldo MA, Cosentino L, Damone LA, Diakaki M, Domingo-Pardo C, Dressler R, Dupont E, Durán I, Fernández-Domínguez B, Ferrari A, Ferreira P, Finocchiaro P, Furman V, Göbel K, García AR, Gawlik-Ramięga A, Glodariu T, Gonçalves IF, González-Romero E, Goverdovski A, Griesmayer E, Guerrero C, Gunsing F, Harada H, Heftrich T, Heinitz S, Heyse J, Jenkins DG, Jericha E, Käppeler F, Kadi Y, Katabuchi T, Kavrigin P, Ketlerov V, Khryachkov V, Kimura A, Kivel N, Kokkoris M, Krtička M, Leal-Cidoncha E, Leeb H, Lerendegui-Marco J, Meo SL, Lonsdale SJ, Losito R, Macina D, Marganiec J, Martínez T, Massimi C, Mastinu P, Mastromarco M, Matteucci F, Maugeri EA, Mendoza E, Mengoni A, Milazzo PM, Mingrone F, Mirea M, Montesano S, Musumarra A, Nolte R, Oprea A, Patronis N, Pavlik A, Perkowski J, Porras I, Praena J, Quesada JM, Rajeev K, Rauscher T, Reifarth R, Riego-Perez A, Rout PC, Rubbia C, Ryan JA, Sabaté-Gilarte M, Saxena A, Schillebeeckx P, Schmidt S, Schumann D, Sedyshev P, Smith AG, Stamatopoulos A, Tagliente G, Tain JL, Tarifeño-Saldivia A, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Wallner A, Warren S, Weigand M, Weiss C, Wolf C, Woods PJ, Wright T, and Žugec P

Abstract

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment., (© The Author(s) 2022.)

Published
2022
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19. Neutron Capture on the s-Process Branching Point ^{171}Tm via Time-of-Flight and Activation.

Author

Guerrero C, Lerendegui-Marco J, Paul M, Tessler M, Heinitz S, Domingo-Pardo C, Cristallo S, Dressler R, Halfon S, Kivel N, Köster U, Maugeri EA, Palchan-Hazan T, Quesada JM, Rochman D, Schumann D, Weissman L, Aberle O, Amaducci S, Andrzejewski J, Audouin L, Bécares V, Bacak M, Balibrea J, Barak A, Barbagallo M, Barros S, Bečvář F, Beinrucker C, Berkovits D, Berthoumieux E, Billowes J, Bosnar D, Brugger M, Buzaglo Y, Caamaño M, Calviño F, Calviani M, Cano-Ott D, Cardella R, Casanovas A, Castelluccio DM, Cerutti F, Chen YH, Chiaveri E, Colonna N, Cortés G, Cortés-Giraldo MA, Cosentino L, Dafna H, Damone A, Diakaki M, Dietz M, Dupont E, Durán I, Eisen Y, Fernández-Domínguez B, Ferrari A, Ferreira P, Finocchiaro P, Furman V, Göbel K, García AR, Gawlik A, Glodariu T, Gonçalves IF, González-Romero E, Goverdovski A, Griesmayer E, Gunsing F, Harada H, Heftrich T, Heyse J, Hirsh T, Jenkins DG, Jericha E, Käppeler F, Kadi Y, Kaizer B, Katabuchi T, Kavrigin P, Ketlerov V, Khryachkov V, Kijel D, Kimura A, Kokkoris M, Kriesel A, Krtička M, Leal-Cidoncha E, Lederer-Woods C, Leeb H, Lo Meo S, Lonsdale SJ, Losito R, Macina D, Manna A, Marganiec J, Martínez T, Massimi C, Mastinu P, Mastromarco M, Matteucci F, Mendoza E, Mengoni A, Milazzo PM, Millán-Callado MA, Mingrone F, Mirea M, Montesano S, Musumarra A, Nolte R, Oprea A, Patronis N, Pavlik A, Perkowski J, Piersanti L, Porras I, Praena J, Rajeev K, Rauscher T, Reifarth R, Rodríguez-González T, Rout PC, Rubbia C, Ryan JA, Sabaté-Gilarte M, Saxena A, Schillebeeckx P, Schmidt S, Shor A, Sedyshev P, Smith AG, Stamatopoulos A, Tagliente G, Tain JL, Tarifeño-Saldivia A, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Wallner A, Warren S, Weigand M, Weiss C, Wolf C, Woods PJ, Wright T, and Žugec P

Abstract

The neutron capture cross sections of several unstable nuclides acting as branching points in the s process are crucial for stellar nucleosynthesis studies. The unstable ^{171}Tm (t_{1/2}=1.92  yr) is part of the branching around mass A∼170 but its neutron capture cross section as a function of the neutron energy is not known to date. In this work, following the production for the first time of more than 5 mg of ^{171}Tm at the high-flux reactor Institut Laue-Langevin in France, a sample was produced at the Paul Scherrer Institute in Switzerland. Two complementary experiments were carried out at the neutron time-of-flight facility (n_TOF) at CERN in Switzerland and at the SARAF liquid lithium target facility at Soreq Nuclear Research Center in Israel by time of flight and activation, respectively. The result of the time-of-flight experiment consists of the first ever set of resonance parameters and the corresponding average resonance parameters, allowing us to make an estimation of the Maxwellian-averaged cross sections (MACS) by extrapolation. The activation measurement provides a direct and more precise measurement of the MACS at 30 keV: 384(40) mb, with which the estimation from the n_TOF data agree at the limit of 1 standard deviation. This value is 2.6 times lower than the JEFF-3.3 and ENDF/B-VIII evaluations, 25% lower than that of the Bao et al. compilation, and 1.6 times larger than the value recommended in the KADoNiS (v1) database, based on the only previous experiment. Our result affects the nucleosynthesis at the A∼170 branching, namely, the ^{171}Yb abundance increases in the material lost by asymptotic giant branch stars, providing a better match to the available pre-solar SiC grain measurements compared to the calculations based on the current JEFF-3.3 model-based evaluation.

Published
2020
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20. ^{7}Be(n,p)^{7}Li Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN.

Author

Damone L, Barbagallo M, Mastromarco M, Mengoni A, Cosentino L, Maugeri E, Heinitz S, Schumann D, Dressler R, Käppeler F, Colonna N, Finocchiaro P, Andrzejewski J, Perkowski J, Gawlik A, Aberle O, Altstadt S, Ayranov M, Audouin L, Bacak M, Balibrea-Correa J, Ballof J, Bécares V, Bečvář F, Beinrucker C, Bellia G, Bernardes AP, Berthoumieux E, Billowes J, Borge MJG, Bosnar D, Brown A, Brugger M, Busso M, Caamaño M, Calviño F, Calviani M, Cano-Ott D, Cardella R, Casanovas A, Castelluccio DM, Catherall R, Cerutti F, Chen YH, Chiaveri E, Correia JGM, Cortés G, Cortés-Giraldo MA, Cristallo S, Diakaki M, Dietz M, Domingo-Pardo C, Dorsival A, Dupont E, Duran I, Fernandez-Dominguez B, Ferrari A, Ferreira P, Furman W, Ganesan S, García-Rios A, Gilardoni S, Glodariu T, Göbel K, Gonçalves IF, González-Romero E, Goodacre TD, Griesmayer E, Guerrero C, Gunsing F, Harada H, Heftrich T, Heyse J, Jenkins DG, Jericha E, Johnston K, Kadi Y, Kalamara A, Katabuchi T, Kavrigin P, Kimura A, Kivel N, Köster U, Kokkoris M, Krtička M, Kurtulgil D, Leal-Cidoncha E, Lederer-Woods C, Leeb H, Lerendegui-Marco J, Lo Meo S, Lonsdale SJ, Losito R, Macina D, Marganiec J, Marsh B, Martínez T, Masi A, Massimi C, Mastinu P, Matteucci F, Mazzone A, Mendoza E, Milazzo PM, Mingrone F, Mirea M, Musumarra A, Negret A, Nolte R, Oprea A, Patronis N, Pavlik A, Piersanti L, Piscopo M, Plompen A, Porras I, Praena J, Quesada JM, Radeck D, Rajeev K, Rauscher T, Reifarth R, Riego-Perez A, Rothe S, Rout P, Rubbia C, Ryan J, Sabaté-Gilarte M, Saxena A, Schell J, Schillebeeckx P, Schmidt S, Sedyshev P, Seiffert C, Smith AG, Sosnin NV, Stamatopoulos A, Stora T, Tagliente G, Tain JL, Tarifeño-Saldivia A, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Wallner A, Warren S, Weigand M, Weiß C, Wolf C, Woods PJ, Wright T, and Žugec P

Abstract

We report on the measurement of the ^{7}Be(n,p)^{7}Li 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 key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a ^{7}Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal ^{7}Li(p,n)^{7}Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+^{7}Li reaction is also discussed.

Published
2018
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21. Strong Neutron Pairing in core+4n Nuclei.

Author

Revel A, Marqués FM, Sorlin O, Aumann T, Caesar C, Holl M, Panin V, Vandebrouck M, Wamers F, Alvarez-Pol H, Atar L, Avdeichikov V, Beceiro-Novo S, Bemmerer D, Benlliure J, Bertulani CA, Boillos JM, Boretzky K, Borge MJG, Caamaño M, Casarejos E, Catford WN, Cederkäll J, Chartier M, Chulkov L, Cortina-Gil D, Cravo E, Crespo R, Datta Pramanik U, Díaz Fernández P, Dillmann I, Elekes Z, Enders J, Ershova O, Estradé A, Farinon F, Fraile LM, Freer M, Galaviz D, Geissel H, Gernhäuser R, Golubev P, Göbel K, Hagdahl J, Heftrich T, Heil M, Heine M, Heinz A, Henriques A, Ignatov A, Johansson HT, Jonson B, Kahlbow J, Kalantar-Nayestanaki N, Kanungo R, Kelic-Heil A, Knyazev A, Kröll T, Kurz N, Labiche M, Langer C, Le Bleis T, Lemmon R, Lindberg S, Machado J, Marganiec J, Movsesyan A, Nacher E, Najafi M, Nilsson T, Nociforo C, Paschalis S, Perea A, Petri M, Pietri S, Plag R, Reifarth R, Ribeiro G, Rigollet C, Röder M, Rossi D, Savran D, Scheit H, Simon H, Syndikus I, Taylor JT, Tengblad O, Thies R, Togano Y, Velho P, Volkov V, Wagner A, Weick H, Wheldon C, Wilson G, Winfield JS, Woods P, Yakorev D, Zhukov M, Zilges A, and Zuber K

Abstract

The emission of neutron pairs from the neutron-rich N=12 isotones ^{18}C and ^{20}O has been studied by high-energy nucleon knockout from ^{19}N and ^{21}O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay ^{19}N(-1p)^{18}C^{*}→^{16}C+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a ^{14}C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay ^{21}O(-1n)^{20}O^{*}→^{18}O+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the ^{16}O core and reduces the number of pairs.

Published
2018
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22. Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength.

Author

Atar L, Paschalis S, Barbieri C, Bertulani CA, Díaz Fernández P, Holl M, Najafi MA, Panin V, Alvarez-Pol H, Aumann T, Avdeichikov V, Beceiro-Novo S, Bemmerer D, Benlliure J, Boillos JM, Boretzky K, Borge MJG, Caamaño M, Caesar C, Casarejos E, Catford W, Cederkall J, Chartier M, Chulkov L, Cortina-Gil D, Cravo E, Crespo R, Dillmann I, Elekes Z, Enders J, Ershova O, Estrade A, Farinon F, Fraile LM, Freer M, Galaviz Redondo D, Geissel H, Gernhäuser R, Golubev P, Göbel K, Hagdahl J, Heftrich T, Heil M, Heine M, Heinz A, Henriques A, Hufnagel A, Ignatov A, Johansson HT, Jonson B, Kahlbow J, Kalantar-Nayestanaki N, Kanungo R, Kelic-Heil A, Knyazev A, Kröll T, Kurz N, Labiche M, Langer C, Le Bleis T, Lemmon R, Lindberg S, Machado J, Marganiec-Gałązka J, Movsesyan A, Nacher E, Nikolskii EY, Nilsson T, Nociforo C, Perea A, Petri M, Pietri S, Plag R, Reifarth R, Ribeiro G, Rigollet C, Rossi DM, Röder M, Savran D, Scheit H, Simon H, Sorlin O, Syndikus I, Taylor JT, Tengblad O, Thies R, Togano Y, Vandebrouck M, Velho P, Volkov V, Wagner A, Wamers F, Weick H, Wheldon C, Wilson GL, Winfield JS, Woods P, Yakorev D, Zhukov M, Zilges A, and Zuber K

Abstract

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R^{3}B/LAND setup with incident beam energies in the range of 300-450  MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type ^{A}O(p,2p)^{A-1}N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

Published
2018
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23. ^{7}Be(n,α)^{4}He Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN.

Author

Barbagallo M, Musumarra A, Cosentino L, Maugeri E, Heinitz S, Mengoni A, Dressler R, Schumann D, Käppeler F, Colonna N, Finocchiaro P, Ayranov M, Damone L, Kivel N, Aberle O, Altstadt S, Andrzejewski J, Audouin L, Bacak M, Balibrea-Correa J, Barros S, Bécares V, Bečvář F, Beinrucker C, Berthoumieux E, Billowes J, Bosnar D, Brugger M, Caamaño M, Calviani M, Calviño F, Cano-Ott D, Cardella R, Casanovas A, Castelluccio DM, Cerutti F, Chen YH, Chiaveri E, Cortés G, Cortés-Giraldo MA, Cristallo S, Diakaki M, Domingo-Pardo C, Dupont E, Duran I, Fernandez-Dominguez B, Ferrari A, Ferreira P, Furman W, Ganesan S, García-Rios A, Gawlik A, Glodariu T, Göbel K, Gonçalves IF, González-Romero E, Griesmayer E, Guerrero C, Gunsing F, Harada H, Heftrich T, Heyse J, Jenkins DG, Jericha E, Katabuchi T, Kavrigin P, Kimura A, Kokkoris M, Krtička M, Leal-Cidoncha E, Lerendegui J, Lederer C, Leeb H, Lo Meo S, Lonsdale SJ, Losito R, Macina D, Marganiec J, Martínez T, Massimi C, Mastinu P, Mastromarco M, Mazzone A, Mendoza E, Milazzo PM, Mingrone F, Mirea M, Montesano S, Nolte R, Oprea A, Pappalardo A, Patronis N, Pavlik A, Perkowski J, Piscopo M, Plompen A, Porras I, Praena J, Quesada J, Rajeev K, Rauscher T, Reifarth R, Riego-Perez A, Rout P, Rubbia C, Ryan J, Sabate-Gilarte M, Saxena A, Schillebeeckx P, Schmidt S, Sedyshev P, Smith AG, Stamatopoulos A, Tagliente G, Tain JL, Tarifeño-Saldivia A, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Vollaire J, Wallner A, Warren S, Weigand M, Weiß C, Wolf C, Woods PJ, Wright T, and Žugec P

Abstract

The energy-dependent cross section of the ^{7}Be(n,α)^{4}He reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of ^{7}Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure ^{7}Be, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two Si-^{7}Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.

Published
2016
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24. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment.

Author

Ruiz A, Timke T, van de Sande A, Heftrich T, Novotny R, and Austin T

Abstract

This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure.

Published
2016
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