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51. Field emission assisted micro plasma discharges at vacuum and atmospheric pressures

Author

Matthias Lindner, Christoph Langer, Dominik Berndt, Christian Prommesberger, and Rupert Schreiner

Subjects
010302 applied physics, Materials science, Atmospheric pressure, Field (physics), business.industry, Microplasma, Plasma, 01 natural sciences, 010305 fluids & plasmas, law.invention, Ignition system, Field electron emission, Physics::Plasma Physics, law, Physics::Space Physics, 0103 physical sciences, Optoelectronics, Millimeter, business, Alternating current
Abstract

Spatially confined non-equilibrium plasmas at vacuum and atmospheric pressure in the dimensions from a few microns to one millimeter are a promising approach to the generation and maintenance of stable glow discharges. The realization of these micro-discharges or micro-plasmas enable more accurate investigations in the field of micro plasma research. We report on field emission assisted micro plasmas excited by an alternating current with frequencies up to 1 kHz. Due to the field enhancement caused by an array of Si nano-tip structures the ignition voltage of stable plasma discharges can be reduced by 30%.

Published
2018

52. Field emission current investigation of p-type and metallized silicon emitters in the frequency domain

Author

R. Lawrowski, Felix Düsberg, Matthias Hausladen, Andreas Pahlke, Michael Bachmann, Christoph Langer, Christian Prommesberger, Rupert Schreiner, and Mikhail Shamonin

Subjects
010302 applied physics, Materials science, Silicon, business.industry, 05 social sciences, chemistry.chemical_element, 01 natural sciences, Cathode, law.invention, Field electron emission, chemistry, law, Frequency domain, 0502 economics and business, 0103 physical sciences, Optoelectronics, business, Saturation (magnetic), 050203 business & management, Voltage, Common emitter, Light-emitting diode
Abstract

We investigated two different field emitter arrays consisting of 10 \times10 p-type and 10 \times 10 undoped Au-coated high aspect ratio silicon tips. The I-V characterization of the p-type sample showed a pronounced saturation for voltages higher than 500 V and a maximum emission current of 39 nA. The metallized sample revealed a FN-like emission up to several \mu A. The metallized and the p-type sample operating below the saturation region showed high current fluctuations of \pm 16 %. Whereas, the metallized sample with current regulation and the p-type sample in the saturation yielded a current stability of \pm 0.4 % and \pm 0.3 %, respectively. Investigations in the frequency domain revealed the for field emission typical 1/f-noise. By operating in the saturation region (p-type sample) or using an emission current regulation (metallized sample) the noise level was reduced by at least 20 dB. Finally, the p-type sample was illuminated by a light emitting diode to increase and modulate the emission current in the saturation region. The emission current was increased by a factor of 3.7 to 145 nA. With this configuration we emulated an unstable emission behavior and evaluated the performance of our emission current regulation circuit.

Published
2018

53. Nano Emitters on Silicon Pillar Structures generated by a Focused Electron Beam Induced Deposition

Author

Rupert Schreiner, R. Lawrowski, Christoph Langer, and J. Sellmair

Subjects
010302 applied physics, Materials science, Silicon, business.industry, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Field electron emission, chemistry, Etching (microfabrication), 0103 physical sciences, Nano, Optoelectronics, Vacuum chamber, Electron beam-induced deposition, 0210 nano-technology, business, Platinum, Diode
Abstract

Nano emitters were deposited by focused electron beam induced deposition of Trimethyl-(methylcyclopentadienyl)platinum(IV) on top of silicon pillars. The nano emitters were exactly positioned in the center on the top of up to four pillars of a quadratic arranged array of sixteen pillars with a pitch of 50 μm. Integral field emission measurements were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10-9 mbar. The Fowler-Nordheim plots show a linear behavior, like expected for an n-type silicon material and a metal needle. The I-V measurement of the most promising sample shows an integral emission current up to 2 μm at a voltage of 600 V (12 MV/m) and an onset voltage for a current of 1 nA of about 300 V.

Published
2018

54. Measurement and resonance analysis of the S33(n,α)Si30 cross section at the CERN n_TOF facility in the energy region from 10 to 300 keV

Author

C. Carrapiço, Tanja Heftrich, G. Cortes, A. Riego-Perez, D. Tarrío, M. S. Robles, Jeri Kroll, Ignacio Porras, M. Mastromarco, J. Lerendegui-Marco, A. Mengoni, M. P. W. Chin, M. B. Gomez-Hornillos, J. Andrzejewski, I. F. Gonçalves, Fabio Belloni, Javier Praena, Massimo Barbagallo, R. Sarmento, V. Ketlerov, Anton Wallner, Ariel Tarifeño-Saldivia, C. Paradela, P. Vaz, D. Cano-Ott, M. A. Cortés-Giraldo, L. Audouin, F. Bečvář, V. Khryachkov, C. Weiss, Srinivasan Ganesan, M. Diakaki, P. M. Milazzo, E. Chiaveri, E. Mendoza, C. Lampoudis, P. F. Mastinu, V. Furman, T. J. Wright, Roberto Losito, A. Pavlik, F. Gunsing, Tatsuya Katabuchi, A. Ventura, Peter Schillebeeckx, C. Domingo-Pardo, Claudia Lederer-Woods, M. Sabaté-Gilarte, Cristian Massimi, Damir Bosnar, A. Manousos, Y. Kadi, V. Bécares, E. Leal-Cidoncha, C. Eleftheriadis, Rene Reifarth, Stefan Schmidt, R. Vlastou, E. Berthoumieux, M. Kokkoris, Thomas Rauscher, J. Marganiec, Vittorio Boccone, J. M. Quesada, D. G. Jenkins, M. Mirea, P. V. Sedyshev, L. Tassan-Got, A. Mallick, G. Vannini, D. Karadimos, Petar Žugec, Willy Mondelaers, F. Calviño, H. Leeb, A. K. Saxena, Christoph Langer, J. Perkowski, A. Hernández-Prieto, Arnaud Ferrari, E. González-Romero, J. Billowes, Mario Weigand, Kathrin Göbel, A. R. García, Rugard Dressler, Jan Heyse, A. Tsinganis, F. Cerutti, M. J. Vermeulen, M. Brugger, Nicola Colonna, E. Jericha, L.S. Leong, S. Valenta, Dorothea Schumann, Vasilis Vlachoudis, J. A. Ryan, Marco Calviani, S. Altstadt, K. Fraval, M. Dietz, Carlos Guerrero, G. Giubrone, G. Tagliente, J. L. Tain, F. Käppeler, Niko Kivel, V. Variale, A. Goverdovski, P. E. Koehler, F. Mingrone, C. Rubbia, I. Duran, M. Krtička, T. Martinez, T. Ware, E. Griesmayer, and A. J. M. Plompen

Subjects
Physics, Nuclear reaction, Large Hadron Collider, 010308 nuclear & particles physics, Resolution (electron density), Resonance, MicroMegas detector, 01 natural sciences, Neutron temperature, Nuclear physics, Cross section (physics), 0103 physical sciences, Neutron, 010306 general physics
Abstract

The 33S(n, α)30Si cross section has been measured at the neutron time-of-flight (n_TOF) facility at CERN in the neutron energy range from 10 to 300 keV relative to the 10B(n, α)7Li cross-section standard. Both reactions were measured simultaneously with a set of micromegas detectors. The flight path of 185 m has allowed us to obtain the cross section with high-energy resolution. An accurate description of the resonances has been performed by means of the multilevel multichannel R-matrix code SAMMY. The results show a significantly higher area of the biggest resonance (13.45 keV) than the unique high-resolution (n, α) measurement. The new parametrization of the 13.45-keV resonance is similar to that of the unique transmission measurement. This resonance is a matter of research in neutron-capture therapy. The 33S(n, α)30Si cross section has been studied in previous works because of its role in the production of 36S in stars, which is currently overproduced in stellar models compared to observations.

Published
2018

55. Correction to: Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset

Author

Willem B. Meijboom, Jean-Claude Tardif, Thorsten R. C. Johnson, Robert Haase, Philipp A. Kaufmann, Robert Roehle, Bernhard Gerber, U. Joseph Schoepf, Bernhard A. Herzog, Marc Dewey, Narinder Paul, Jonathan Leipsic, Abbas Arjmand Shabestari, Bjarne L. Nørgaard, Hatem Alkadhi, Yung-Liang Wan, Geir R. Ulimoen, David Maintz, Koen Nieman, Elke Zimmermann, Jean Pierre Laissy, Juhani Knuuti, Lily Honoris, Kristian A. Øvrehus, Arthur J. Scholte, Hiroyuki Niinuma, Melvin E. Clouse, Georg M. Schuetz, Matthijs F.L. Meijs, Akira Sato, Albert de Roos, Vladimir Mendoza Rodriguez, Daniele Andreini, David E. Bush, Axel Cosmus Pyndt Diederichsen, Lin Yang, Ashraf Hamdan, Said Ghostine, Christoph Langer, Sebastian Leschka, David A. Halon, Carlos E. Rochitte, Zhaoqi Zhang, Viktoria Wieske, Peter Schlattmann, Simone Muraglia, Benjamin J.W. Chow, Pascal Gueret, R.R. Buechel, Roy P. Marcus, Kai Sun, Gianluca Pontone, Bjørn Arild Halvorsen, Michael Laule, Jörg Hausleiter, Hans Mickley, Shona M.M. Jenkins, Konstantin Nikolaou, Harald Brodoefel, Eugenio Martuscelli, John Hoe, Mehraj Sheikh, Nuno Bettencourt, Mario J. Garcia, Reda Jakamy, Johannes Rixe, UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, and UCL - (SLuc) Service de pathologie cardiovasculaire

Subjects
medicine.medical_specialty, business.industry, Nice, Mistake, General Medicine, Guideline, Chest pain, Pre- and post-test probability, Radiology Nuclear Medicine and imaging, medicine, Radiology, Nuclear Medicine and imaging, In patient, Radiology, medicine.symptom, Recent onset, business, computer, computer.programming_language
Abstract

The original version of this article, published on 19 March 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The names of the authors Philipp A. Kaufmann, Ronny Ralf Buechel and Bernhard A. Herzog were presented incorrectly.

Published
2018

56. Measurement and analysis of theAm241neutron capture cross section at the n_TOF facility at CERN

Author

J. Lerendegui-Marco, Carlos Guerrero, S. Andriamonje, I. Dillmann, Jan Heyse, P. E. Koehler, E. Leal-Cidoncha, C. Eleftheriadis, S. Altstadt, I. F. Gonçalves, E. Chiaveri, P. F. Mastinu, Thomas Rauscher, Fabio Belloni, C. Weiss, G. Tagliente, M. Mirea, S. Heinitz, V. Bécares, D. Karadimos, M. Mastromarco, P. V. Sedyshev, A. Mengoni, M. S. Robles, D. López, Massimo Barbagallo, Roberto Losito, N. Colonna, A. K. Saxena, F. Mingrone, C. Lederer, I. Duran, Tatsuya Katabuchi, A. Ventura, M. P. W. Chin, V. Ketlerov, F. Roman, Srinivasan Ganesan, F. Calviño, H. Leeb, C. Carrapiço, Arnaud Ferrari, C. Paradela, Anton Wallner, Ariel Tarifeño-Saldivia, M. B. Gomez-Hornillos, B. Berthier, F. Cerutti, J. Billowes, P. Gurusamy, L. Audouin, J. Balibrea, A. Goverdovski, M. J. Vermeulen, V. Khryachkov, A. Tsinganis, J. Andrzejewski, Tanja Heftrich, A. Hernández-Prieto, F. Bečvář, E. González, Jeri Kroll, P. Vaz, S. Valenta, J. Perkowski, L.S. Leong, A. Riego-Perez, P. M. Milazzo, D. Cano-Ott, A. R. García, Marco Calviani, T. Ware, Vasilis Vlachoudis, K. Fraval, R. Sarmento, M. Brugger, F. Gramegna, M. Kokkoris, E. Mendoza, E. Griesmayer, A. J. M. Plompen, M. Krtička, M. Diakaki, Javier Praena, F. Käppeler, V. Variale, Peter Schillebeeckx, N. Dzysiuk, Rene Reifarth, T. Martinez, Roberto Versaci, Willy Mondelaers, Christoph Langer, G. Giubrone, Stefan Schmidt, C. Lampoudis, A. Pavlik, Y. Kadi, C. Rubbia, Mario Weigand, A. Manousos, C. Domingo-Pardo, J. M. Quesada, L. Tassan-Got, E. Jericha, J. Marganiec, M. Sabaté-Gilarte, Dorothea Schumann, J. A. Ryan, F. Gunsing, J. L. Tain, D. Bosnar, Cristian Massimi, R. Vlastou, E. Berthoumieux, M. A. Cortés-Giraldo, Petar Žugec, G. Cortes, D. Tarrío, V. Furman, T. J. Wright, G. Vannini, D. G. Jenkins, and M. Licata

Subjects
Nuclear reaction, Physics, 010308 nuclear & particles physics, Resonance, 01 natural sciences, 7. Clean energy, Neutron temperature, Calorimeter, Nuclear physics, Cross section (physics), Neutron capture, 0103 physical sciences, Neutron cross section, Neutron, 010306 general physics
Abstract

The Am241(n,γ) cross section has been measured at the n-TOF facility at CERN with the n-TOF BaF2 Total Absorption Calorimeter in the energy range between 0.2 eV and 10 keV. Our results are analyzed as resolved resonances up to 700 eV, allowing a more detailed description of the cross section than in the current evaluations, which contain resolved resonances only up to 150-160 eV. The cross section in the unresolved resonance region is perfectly consistent with the predictions based on the average resonance parameters deduced from the resolved resonances, thus obtaining a consistent description of the cross section in the full neutron energy range under study. Below 20 eV, our results are in reasonable agreement with JEFF-3.2 as well as with the most recent direct measurements of the resonance integral, and differ up to 20-30% with other experimental data. Between 20 eV and 1 keV, the disagreement with other experimental data and evaluations gradually decreases, in general, with the neutron energy. Above 1 keV, we find compatible results with previously existing values.

Published
2018

57. Comparison of electromagnetic and nuclear dissociation of Ne-17

Author

H. O. U. Fynbo, Deniz Savran, F. Aksouh, Christoph Langer, D. Cortina-Gil, J. Hoffman, Mattias Lantz, Michael Heil, O. Kiselev, W. Ott, Achim Richter, Thomas Aumann, K. Riisager, R. Kulessa, Björn Jonson, C. Lehr, L. M. Fraile, Dieter H. H. Hoffmann, Ángel Perea, J. Marganiec, Carlos A. Bertulani, C. Nociforo, Marielle Chartier, C. Karagiannis, Thomas Nilsson, Stefan Typel, V. Panin, F. Wamers, Y. Aksyutina, Hans Geissel, K. Sümmerer, Ralf Plag, H. Emling, Stefanos Paschalis, S. Beceiro-Novo, N. Kurz, O. Ershova, K. Mahata, Roy Crawford Lemmon, C. Wimmer, J. V. Kratz, D. Galaviz, A. Chatillon, Herbert A. Simon, T. Le Bleis, Olof Tengblad, Helmut Weick, Håkan T Johansson, H. Alvarez-Pol, C. Muntz, Michael Wiescher, Yu. A. Litvinov, D. M. Rossi, C. Rodriguez-Tajes, Joachim Stroth, M. J. G. Borge, G. Schrieder, K. Boretzky, Rene Reifarth, L. Chulkov, Department of Energy (US), National Science Foundation (US), German Research Foundation, Federal Ministry of Education and Research (Germany), European Money Markets Institute, Helmholtz International Center for FAIR, Technische Universität Darmstadt, and Ministerio de Economía y Competitividad (España)

Subjects
Physics, COLLISIONS, Internal energy, 010308 nuclear & particles physics, 01 natural sciences, 7. Clean energy, STATE, Dissociation (chemistry), Coincidence, CAPTURE, Reaction rate, medicine.anatomical_structure, Fragmentation (mass spectrometry), 0103 physical sciences, medicine, Halo, Atomic physics, 010306 general physics, Ground state, DECAY, Nucleus
Abstract

8 pags., 10 figs., 3 tabs., The Borromean drip-line nucleus Ne-17 has been suggested to possess a two-proton halo structure in its ground state. In the astrophysical rp-process, where the two-proton capture reaction O-15(2p,gamma) Ne-17 plays an important role, the calculated reaction rate differs by several orders of magnitude between different theoretical approaches. To add to the understanding of the Ne-17 structure we have studied nuclear and electromagnetic dissociation. A 500 MeV/u Ne-17 beam was directed toward lead, carbon, and polyethylene targets. Oxygen isotopes in the final state were measured in coincidence with one or two protons. Different reaction branches in the dissociation of Ne-17 were disentangled. The relative populations of s and d states in F-16 were determined for light and heavy targets. The differential cross section for electromagnetic dissociation (EMD) shows a continuous internal energy spectrum in the three-body system O-15 + 2p. The Ne-17 EMD data were compared to current theoretical models. None of them, however, yields satisfactory agreement with the experimental data presented here. These new data may facilitate future development of adequate models for description of the fragmentation process., This project is supported by NAVI, GSI-TU Darmstadt cooperation, HIC for FAIR, EMMI, and BMBF and from DFG through Grant No. SFB1245 and from BMBF via Project No. 05P15RDFN1, and from the Spanish Ministry by research grant FPA2015-64969-P. C.A.B. acknowledges support by the US DOE Grant No. DE-FG02-08ER41533 and the US NSF Grant No. 1415656.

Published
2018

58. 66.7-keV γ -line intensity of Tm171 determined via neutron activation

Author

Rene Reifarth, C. Wolf, Jan Glorius, Tanja Heftrich, S. Lohse, Kathrin Göbel, D. Renisch, Ch. E. Düllmann, S. Fiebiger, Klaus Eberhardt, Mario Weigand, Christoph Langer, and Raphael Haas

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Atomic physics, 010303 astronomy & astrophysics, 01 natural sciences, Neutron activation, Line (formation), Intensity (physics)
Published
2018

59. The Nuclear astrophysics program at n_TOF (CERN)

Author

C. Massimi, E. Chiaveri, C. Rubbia, P. J. Woods, S. Warren, A. Casanovas, F. Mingrone, M. Sabaté-Gilarte, D. Bosnar, A. Oprea, J. M. Quesada, G. Vannini, E. González, J. A. Ryan, E. Berthoumieux, Sergio Cristallo, I. Porras, J. Perkowski, M. A. Cortés-Giraldo, Mario Barbagallo, G. Cortes, D. Kurtulgil, M. Kokkoris, M. S. Robles, A. Stamatopoulos, L. R. Dressler, M. Bacak, J. Kroll, P. Kavrigin, M. Krtička, C. Weiss, A. Pavlik, F. Gunsing, L. A. Damone, A. Ventura, J. Andrzejewski, A. Riego, T. Glodariu, V. Variale, J. L. Tain, E. Dupont, F. Käppeler, C. Lederer, C. Domingo-Pardo, J. Heyse, Christoph Langer, Dorothea Schumann, H. Leeb, D. Radeck, Ralf Nolte, P. Mastinu, V. Vlachoudis, L. Piersanti, M. Mastromarco, G. Tagliente, J. Marganiec, Y. H. Chen, R. Cardella, B. Fernández-Domínguez, S. Heinitz, D. Cano-Ott, A. Masi, V. Furman, A. S. Brown, P. Finocchiaro, E. Griesmayer, P. M. Milazzo, Anton Wallner, T. Wright, D. G. Jenkins, P. Schillebeeckx, Nicola Colonna, J. Balibrea, Cosentino, N. V. Sosnin, A. Negret, T. Martínez, S. Valenta, E. Jericha, P. Sedyshev, A. Hernandez-Prieto, E. Leal-Cidoncha, Petar Žugec, Simona Losito, E. A. Maugeri, Javier Praena, S. Lo Meo, A. Ferrari, L. Tassan-Got, A. Kalamara, Pedro G. Ferreira, A. Mazzone, L. Audouin, A. Tsinganis, M. Caamaño, I. Duran, Y. Kadi, A. Saxena, Hideo Harada, P. Vaz, D. Macina, Carlos Guerrero, S. Gilardoni, M. Mirea, A. G. Smith, N. Patronis, F. Cerutti, M. Diakaki, R. Vlastou, F. Calviño, Atsushi Kimura, R. Reifarth, J. Billowes, F. Bečvář, E. Mendoza, A. Musumarra, J. Lerendegui-Marco, I. F. Gonçalves, K. Göbel, Ariel Tarifeño-Saldivia, S. J. Lonsdale, O. Aberle, Giulia Clai, A. Gawlik, Thomas Rauscher, A. R. García, Marco Calviani, N. Kivel, A. Mengoni, A. Mallik, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, 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 de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, Mengoni, A., Lo Meo, S., Clai, G., 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), Colonna, N., La Cognata, M., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Cosentino, Null, Cristallo, S., Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, L. R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Hernandez-Prieto, A., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Kroll, J., Krtička, M., Kurtulgil, D., Langer, C., Leal-Cidoncha, E., Lederer, C., Lerendegui-Marco, J., Leeb, H., Lonsdale, S. J., Losito, S., Macina, D., Mallik, A., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mingrone, F., Milazzo, P. M., Mirea, M., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Piersanti, L., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Riego, A., Robles, M. S., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., 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., Weiss, C., Woods, P. J., Wright, T., Žugec, P., and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear

Subjects
Nuclear reaction, Astrofísica, Astrophysics and Astronomy, Cross-section, nTOF, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Astrophysics, 01 natural sciences, 7. Clean energy, n_TOF, nuclear astrophysics, CERN, Nuclear physics, Physics and Astronomy (all), Stellar nucleosynthesis, Big Bang nucleosynthesis, Nucleosynthesis, 0103 physical sciences, CERN, Nuclear astrophysics, Astrophysics::Solar and Stellar Astrophysics, Nuclear Physics - Experiment, Neutron induced nuclear reactions, 010306 general physics, Nuclear Experiment, Astrophysics::Galaxy Astrophysics, Physics, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, Neutron capture, 13. Climate action, Neutron source, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleosíntesi
Abstract

An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis. Several neutron capture reactions relevant to s-process nucleosynthesis have been measured so far, some of which on important branching point radioisotopes. Furthermore, the construction of a second experimental area has recently opened the way to challenging measurements of (n, charged particle) reactions on isotopes of short half-life. The Nuclear Astrophysics program of the n_TOF Collaboration is here described, with emphasis on recent results relevant for stellar nucleosynthesis, stellar neutron sources and primordial nucleosynthesis., We acknowledge the support by the Narodowe Centrum Nauki (NCN), under the Grant No. UMO-2012/04/M/ST2/00700.

Published
2018

60. Nuclear astrophysics at FRANZ

Author

Jan Glorius, Kathrin Göbel, P Hillmann, C. Wolf, D. Veltum, Christoph Wiesner, A. Zadeh, Mario Weigand, Tanja Heftrich, M Heil, Z. Slavkovská, R. Plag, S. Dababneh, Oliver Meusel, Rene Reifarth, Stefan Schmidt, Christoph Langer, and S. Fiebiger

Subjects
Nuclear reaction, Physics, History, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Isotopes of krypton, 01 natural sciences, Computer Science Applications, Education, Calorimeter, Nuclear physics, Neutron capture, 0103 physical sciences, Measuring instrument, Neutron cross section, Nuclear astrophysics, Neutron, ddc:530, Nuclear Experiment, 010306 general physics
Abstract

NUCLEAR PHYSICS IN ASTROPHYSICS CONFERENCE (NPA VII), York, England, 15 May 2015 - 22 May 2015; Journal of physics / Conference Series 940, 012024 (2018). doi:10.1088/1742-6596/940/1/012024, Published by IOP Publ., Bristol

Published
2018

61. Measurement of the U238(n,γ) cross section up to 80 keV with the Total Absorption Calorimeter at the CERN n_TOF facility

Author

M. P. W. Chin, F. Roman, A. R. García, M. Brugger, E. Leal-Cidoncha, C. Eleftheriadis, Thomas Rauscher, D. Karadimos, E. González-Romero, Rene Reifarth, F. Käppeler, M. S. Robles, G. Cortes, F. Gunsing, D. Tarrío, G. Tagliente, Furman, Cristian Massimi, P. Gurusamy, Srinivasan Ganesan, Stefan Schmidt, J. M. Quesada, L. Tassan-Got, Javier Praena, D. Cano-Ott, M. Diakaki, M. Mirea, A. Manousos, G. Vannini, J. Marganiec, M. Krtička, F. Calviño, C. Carrapiço, H. Leeb, A. K. Saxena, T. Martinez, J. Perkowski, Tanja Heftrich, Tatsuya Katabuchi, A. Ventura, Arnaud Ferrari, J. Billowes, A. Riego-Perez, F. Cerutti, M. A. Cortés-Giraldo, Mario Weigand, E. Chiaveri, M. Kokkoris, P. Vaz, P. F. Mastinu, E. Jericha, Variale, N. Colonna, C. Weiss, C. Paradela, D. Bosnar, Dorothea Schumann, L. Audouin, J. A. Ryan, Massimo Barbagallo, T. J. Wright, Anton Wallner, Christoph Langer, Ketlerov, Khryachkov, A. Hernández-Prieto, S. Valenta, Petar Žugec, C. Lampoudis, A. Pavlik, Marco Calviani, C. Domingo-Pardo, M. Dietz, M. Sabaté-Gilarte, K. Fraval, Jeri Kroll, Roberto Losito, R. Sarmento, G. Giubrone, Y. Kadi, Bécares, A. Tsinganis, D. G. Jenkins, L.S. Leong, Ariel Tarifeño-Saldivia, J. Lerendegui-Marco, P. M. Milazzo, Carlos Guerrero, I. F. Gonçalves, Fabio Belloni, M. J. Vermeulen, P. V. Sedyshev, R. Vlastou, E. Berthoumieux, S. Altstadt, F. Bečvář, E. Mendoza, Peter Schillebeeckx, N. Dzysiuk, Roberto Versaci, P. E. Koehler, I. Duran, T. Ware, E. Griesmayer, J. L. Tain, C. Rubbia, Vlachoudis, M. B. Gomez-Hornillos, J. Andrzejewski, A. Goverdovski, F. Mingrone, C. Lederer, and A. Mengoni

Subjects
Physics, Background subtraction, Range (particle radiation), Large Hadron Collider, 010308 nuclear & particles physics, 01 natural sciences, Neutron temperature, Calorimeter, Nuclear physics, Cross section (physics), 0103 physical sciences, Neutron, 010306 general physics, Absorption (electromagnetic radiation)
Abstract

The radiative capture cross section of a highly pure (99.999%), 6.125(2) grams and 9.56(5) 10-4 atoms/barn areal density 238-U sample has been measured with the Total Absorption Calorimeter (TAC) in the 185 m flight path at the CERN neutron time-of-flight facility n_TOF. This measurement is in response to the NEA High Priority Request list, which demands an accuracy in this cross section of less than 3% below 25 keV. These data have undergone careful background subtraction, with special care being given to the background originating from neutrons scattered by the 238-U sample. Pileup and dead-time effects have been corrected for. The measured cross section covers an energy range between 0.2 eV and 80 keV, with an accuracy that varies with neutron energy, being better than 4% below 25 keV and reaching at most 6% at higher energies.

Published
2017

62. Myocardial Fibrosis in Hypertrophic Cardiomyopathy

Author

Hauke Harders, P.J. Schaefer, Matthias Eden, Mirko Hohnhorst, Norbert Frey, Marcus Both, Matthias Lutz, Christoph Langer, Olav Jansen, and Lothar Faber

Subjects
Male, medicine.medical_specialty, Validation study, Intraclass correlation, Iohexol, Cardiomyopathy, Contrast Media, Magnetic Resonance Imaging, Cine, Multidetector Computed Tomography, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, cardiovascular diseases, Prospective cohort study, Late enhancement, medicine.diagnostic_test, business.industry, Myocardium, Hypertrophic cardiomyopathy, Reproducibility of Results, Heart, Magnetic resonance imaging, Organ Size, Cardiomyopathy, Hypertrophic, Middle Aged, medicine.disease, Fibrosis, Radiographic Image Enhancement, Female, Myocardial fibrosis, Radiology, business, Nuclear medicine
Abstract

INTRODUCTION With subgroups of patients with hypertrophic cardiomyopathy (HCM) confers a 4% to 5% risk for adverse prognosis. Besides left-ventricular muscle mass (LV-MM) myocardial fibrosis (MF) assessable by late gadolinium enhancement in cardiovascular magnetic resonance (LGE-CMR) has been related to that. Myocardial fibrosis can also be demonstrated by late enhancement (LE) in late-enhanced multislice computed tomography (leMDCT). This analysis investigates leMDCT whether to enable quantification of LE load in terms of LE mass by percent LV-MM in HCM. METHODS In a prospective validation study, we included 30 consecutive patients with HCM who underwent leMDCT (64 slice) and LGE-CMR (1.5 T). The leMDCT scan was performed 7 minutes after injection of iodine contrast (Iopromid). Endocardial and epicardial planimetry served for the assessment of LV-MM. Visually detectable LE was quantified using the manual quantification method resulting in LE by percent LV-MM (%LE). The LGE-CMR data served for validation. RESULTS Mean (SD) age was 64.1 (13.9) years. Myocardial fibrosis prevalence was 63.3% (19/30 patients indentified by both leMDCT and LGE-CMR). In leMDCT, tissue density in LE areas compared with normal myocardium was higher (138.2 [23.9] HU vs 98.4 [16.5] HU, P < 0.001) but lower than in the LV cavity (138.2 [23.9] HU vs 169.2 [35.9] HU, P < 0.001). Late enhancement mass in leMDCT seemed to be 7.9 (8.5) g LE versus 8.6 [11] g LGE in CMR (P = 0.497, r = 0.95) resulting in a leMDCT/LGE-CMR relation of 1.2. Referring LE mass to LV-MM gave an LE proportion measured by leMDCT of 4 (3.9) %LE versus 3.9 (4.1) %LGE in LGE-CMR (r = 0.88, P = 0.75). Intraobserver/interobserver reliability of LE mass assessment showed an intraclass correlation coefficient of 0.99 and 0.97. CONCLUSIONS In patients with HCM, leMDCT provides volumetric assessment of LE mass-absolutely and by percent LV-MM.

Published
2015

63. Effective proton-neutron interaction near the drip line from unbound states in F25,26

Author

R. Crespo, Hans Geissel, Ralf Plag, J. Benlliure, Jason D. Holt, H. Hergert, Marine Vandebrouck, Christoph Langer, J. M. Boillos, Z. Elekes, J. Hagdahl, T. Kröll, J. Taylor, J. S. Winfield, A. Kelic-Heil, C. Caesar, Björn Jonson, Rene Reifarth, Roman Gernhäuser, A. Ignatov, D. M. Rossi, D. Galaviz, Joachim Enders, L. Chulkov, Deniz Savran, Ángel Perea, A. Lepailleur, F. Farinon, M. Heine, M. A. Najafi, Mikhail V. Zhukov, Nasser Kalantar-Nayestanaki, Andreas Wagner, T. Le Bleis, J. Kahlbow, Daniel Bemmerer, R. Kanungo, P. Velho, E. Y. Nikolskii, O. Sorlin, C. Wheldon, Thomas Aumann, M. Caamaño, D. Cortina-Gil, Stefanos Paschalis, Andreas Martin Heinz, L. Atar, Iris Dillmann, C. Nociforo, A. Henriques, R. Thies, Jorge Machado, O. Ershova, V. Panin, Marina Petri, Joakim Cederkäll, M. Holl, E. Cravo, Thomas Nilsson, A. Estrade, V. Volkov, W. N. Catford, Olof Tengblad, Vladimir Avdeichikov, Martin Freer, Marielle Chartier, F. Wamers, Simon Lindberg, M. J. G. Borge, Kai Zuber, Kathrin Göbel, Enrique Nácher, M. Röder, U. Datta Pramanik, Catherine Rigollet, H. Alvarez-Pol, Julien Gibelin, K. Boretzky, Yasuhiro Togano, M. Heil, I. Syndikus, L. M. Fraile, P. Díaz Fernández, A. Knyazev, S. R. Stroberg, S. Beceiro-Novo, Achim Schwenk, Tanja Heftrich, A. Movsesyan, D. Yakorev, A. Hufnagel, J. Marganiec, Helmut Weick, Håkan T Johansson, H. Scheit, Pavel Golubev, F. M. Marqués, Andreas Zilges, M. Labiche, G. L. Wilson, F. de Oliveira Santos, Carlos A. Bertulani, G. Ribeiro, P. J. Woods, S. Pietri, Enrique Casarejos, N. Kurz, Scott Bogner, Herbert A. Simon, and Roy Crawford Lemmon

Subjects
Physics, 010308 nuclear & particles physics, Binding energy, Ab initio, Resonance, 7. Clean energy, 01 natural sciences, Atomic mass, 0103 physical sciences, Bound state, Nuclear force, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Multiplet
Abstract

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The F-26 nucleus, composed of a deeply bound pi 0d(5/2) proton and an unbound v0d(3/2) neutron on top of an O-24 core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J(pi) = 1(1)(+) - 4(1)(+) multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J(pi) = 1(1)(+), 2(1)(+), 4(1)(+) bound states have been determined, and only a clear identification of the J(pi) = 3(1)(+) is missing. Purpose: We wish to complete the study of the J(pi) = 1(1)(+) - 4(1)(+) multiplet in F-26, by studying the energy and width of the J(pi) = 3(1)(+) unbound state. The method was first validated by the study of unbound states in F-25, for which resonances were already observed in a previous experiment. Method: Radioactive beams of Ne-26 and Ne-27, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in F-25 and F-26 via one-proton knockout reactions on a CH2 target, located at the object focal point of the (RB)-B-3/LAND setup. The detection of emitted. rays and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in F-25 and two in F-26. Results: Based on its width and decay properties, the first unbound state in F-25, at the relative energy of 49(9) keV, is proposed to be a J(pi) = 1/ 2(-) arising from a p1/2 proton- hole state. In F-26, the first resonance at 323(33) keV is proposed to be the J(pi) = 3(1)(+) member of the J(pi) = 1(1)(+) - 4(1)(+) multiplet. Energies of observed states in F-25,F-26 have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of F-26.

Published
2017

64. Microrods and microlines by three-dimensional epitaxially grown GaN for field emission cathodes

Author

Christian Prommesberger, Christoph Langer, Rupert Schreiner, and R. Lawrowski

Subjects
010302 applied physics, Materials science, Field (physics), business.industry, Gallium nitride, 02 engineering and technology, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Cathode, Rod, law.invention, chemistry.chemical_compound, Field electron emission, chemistry, law, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, Layer (electronics), Diode
Abstract

The three-dimensional epitaxial technique allows the realization of gallium nitride lines in addition to the rods. To optimize the properties of GaN-based field emission cathodes further investigations and an improvement of the epitaxial process were performed. The microrods and microlines consist of a one-order higher n-doped gallium nitride in comparison to the gallium nitride layer on the sapphire substrate. The typical height of the microrods and -lines is about 5 μm. The field emission properties of these structures were investigated in diode configuration by integral field emission measurements at pressures below 10−9 mbar. For the microrods (microlines) a voltage of 1100 V (2000 V) was measured for a field emission current of about 0.5 μΑ with an onset field of about 12 MV/m (24 MV/m). Furthermore, the field enhancement factors for microrods and -lines are in the range of 300 and 200, respectively.

Published
2017

65. Field emission characterization of in-situ deposited metallic nanocones

Author

Rupert Schreiner, Roustaie Farough, Christoph Langer, Johannes Bieker, and Helmut F. Schlaak

Subjects
010302 applied physics, Fabrication, Materials science, Ion track, Analytical chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, law.invention, Ion, Field electron emission, law, 0103 physical sciences, Electrode, Nanometre, 0210 nano-technology, Common emitter
Abstract

An in-situ fabrication technique based on ion track etched template electrodeposition of metallic nanocones was used for the production of field emitter cathodes. Gold nanocones with a height of 24 microns, a base diameter between 3 to 4 microns and a tip diameter below 300 nanometers were deposited on a circular electrode with a diameter of 2.5 mm. The integral field emission (FE) measurements of samples with cone densities of 6 · 104 cones/cm2 (sample A) and 1 · 106 cones/cm2 (sample B) yielded in a maximum current of 37.5 μA at an applied field of 12.5 V/μm for sample A and 29.1 μA at 9.4 V/μm for sample B. The stability of emission current was investigated for over 48 hours and no degradation was observed.

Published
2017

66. Investigations of the transition from field electron emission to stable plasma discharge in a micro electron source at vacuum pressure

Author

Matthias Lindner, Christoph Langer, Rupert Schreiner, Christian Prommesberger, and Wolfram Knapp

Subjects
010302 applied physics, Materials science, Astrophysics::High Energy Astrophysical Phenomena, Vacuum pressure, Astrophysics::Cosmology and Extragalactic Astrophysics, 02 engineering and technology, Plasma, 021001 nanoscience & nanotechnology, Electron source, 01 natural sciences, Cathode, law.invention, Field electron emission, Physics::Plasma Physics, law, 0103 physical sciences, Evaluation methods, Atomic physics, 0210 nano-technology, Astrophysics::Galaxy Astrophysics
Abstract

We report on the transition from field electron emission to plasma discharges. During an experiment with a miniaturized field emission electron source a plasma discharge accompanied by a luminous effect was observed. A novel graphical evaluation method was used to interpret and to compare the observed phenomenon.

Published
2017

67. Control of the electron source current

Author

Felix Düsberg, R. Lawrowski, Florian Dams, Martin R. Hofmann, Christoph Langer, Christian Prommesberger, Rupert Schreiner, Michael Baclimann, and Andreas Pahlke

Subjects
Materials science, Current ratio, Electrode, Analytical chemistry, Flux, Electron, Current (fluid), Electron source, Stability (probability), Standard deviation, Computational physics
Abstract

A control circuit to stabilize the flux of electrons transmitted through an extractor electrode is presented. By controlling the emission current a fluctuation with a standard deviation of 0.015% is observed. However, the achievable stability of the transmitted electron current is limited due to a variation of the extraction grid current ratio showing a standard deviation of 4.33%. By regulating the difference of the emission current and the extraction grid current an improved stability of the transmitted electron current down to a standard deviation of 0.280% is observed. Even with operation at 2 × 10−5 mbar a standard deviation of 0.558% is achieved.

Published
2017

68. Field emission properties of p-type silicon tips decorated with tungsten nanoparticles

Author

Pavel Serbun, Rupert Schreiner, Alexander N. Obraztsov, Christian Prommesberger, Anton S. Orekhov, Christoph Langer, Dirk Lützenkirchen-Hecht, and Victor I. Kleshch

Subjects
010302 applied physics, Materials science, Silicon, Scanning electron microscope, business.industry, Nanoparticle, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, Tungsten, equipment and supplies, 021001 nanoscience & nanotechnology, 01 natural sciences, Anode, Field electron emission, chemistry, 0103 physical sciences, Optoelectronics, Reactive-ion etching, 0210 nano-technology, business, Saturation (magnetic)
Abstract

An array of conical-shaped p-type silicon tips was fabricated by using reactive ion etching and sharpening oxidation. The apex of each tip was decorated by a tungsten hemispherical nanoparticle. Field emission properties of the tips were measured by a tungsten-needle anode positioned above the tip apex. Tips decorated with tungsten nanoparticles demonstrated a smaller saturation region in current-voltage characteristics compared to the pristine tips. An emission activation process, which consisted in sudden current increase at certain value of applied voltage, was observed for the decorated silicon tips. This behavior was explained by the formation of vertical protrusions extending from the metal particles revealed by scanning electron microscopy after field emission experiments.

Published
2017

69. Benzocyclobutene as a novel integrated spacer material in a field emission electron source

Author

R. Lawrowski, Christian Prommesberger, Christoph Langer, and Rupert Schreiner

Subjects
010302 applied physics, Materials science, Silicon, business.industry, Black silicon, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, law.invention, Anode, Field electron emission, chemistry.chemical_compound, chemistry, law, Etching (microfabrication), Benzocyclobutene, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, Layer (electronics)
Abstract

For the realization of a miniaturized field emission electron source we tested benzocyclobutene (BCB) as a new spacer material between cathode and anode. We fabricated black silicon emitters and characterized the emission behavior with an integrated 5 μm thin and large-area spacer of BCB. The integrated BCB layer allows the realization of a compact electron source with only two components consisting of a cathode with BCB and a grid. The comparison with other spacer materials like polyimide (25 μm thickness) or mica (50 μm thickness) revealed for the cathode with BCB a significantly reduced operational voltage of 240 V for a field emission current of 1 μΑ.

Published
2017

70. Field emission properties of ring-shaped Si ridges with DLC coating

Author

Yifeng Huang, Rupert Schreiner, Juncong She, Christian Prommesberger, Christoph Langer, Mirgen Mecani, and Robert Ławrowski

Subjects
Field electron emission, Materials science, Diamond-like carbon, law, Analytical chemistry, Work function, Vacuum arc, Inductively coupled plasma, Reactive-ion etching, Cathode, Anode, law.invention
Abstract

We report on the fabrication and the emission characterization of single ring-shaped Si ridges with a coating of diamond-like carbon (DLC). The reactive ion etching and the subsequent inductively coupled plasma step were adjusted to realize ring-shaped Si ridges with a height of 7.5 μm respectively 15 μm and an apex radius of 20 – 25 nm. The samples were coated with a DLC layer (thickness ≈ 2 – 5 nm) by a filtered cathodic vacuum arc deposition system in order to lower the work function of the emitter and to improve the field emission characteristics. The field emission characterizations were done in diode configuration with cathode and anode separated by a 50 μm thick mica spacer. A higher emission current was carried out for the ring-shaped Si ridge in comparison to the point-shaped Si tips due to the increased emission area. The highest emission current of 0.22 μA at 1000 V was measured on a DLC-coated sample with the highest aspect ratio. No degradation of the emission current was observed in the plateau regime during a measurement period of 6 h. Finally, no decreasing performance of the field emission properties was found due to changes in the geometry or destructions.

Published
2017

71. Neutron capture cross section measurement ofU238at the CERN n_TOF facility in the energy region from 1 eV to 700 keV

Author

A. Pavlik, C. Domingo-Pardo, J. Marganiec, M. Sabaté-Gilarte, Javier Praena, S. Lo Meo, P. F. Mastinu, L. S. Leong, S. Valenta, P. M. Milazzo, A. K. Saxena, C. Lampoudis, I. F. Gonçalves, J. L. Tain, Marco Calviani, M. Mirea, C. Lederer, E. Chiaveri, D. Cano-Ott, F. Bečvář, M. Mastromarco, F. Gunsing, M. A. Cortés-Giraldo, T. Wright, M. P. W. Chin, Jeri Kroll, E. Jericha, R. Sarmento, F. Mingrone, P. Vaz, C. Weiß, A. Hernández-Prieto, J. Andrzejewski, R. Losito, Carlo Rubbia, S. Schmidt, A. J. M. Plompen, F. Cerutti, A. Riego, Alberto Ventura, Anton Wallner, Alfredo Ferrari, E. Berthoumieux, Cristian Massimi, Srinivasan Ganesan, T. Ware, A. Manousos, F. Käppeler, C. Paradela, Alberto Mengoni, S. Altstadt, R. Vlastou, M. Kokkoris, N. Kivel, E. Griesmayer, E. Leal-Cidoncha, K. Fraval, Damir Bosnar, Petar Žugec, Y. Kadi, V. Bécares, Carlos Guerrero, Mario Barbagallo, C. Eleftheriadis, D. Schumann, M. Krtička, F. Calviño, Thomas Rauscher, T. Martinez, P. Schillebeeckx, D. G. Jenkins, P. E. Koehler, J. Billowes, G. Tagliente, D. Karadimos, Christoph Langer, A. Tsinganis, W. Mondalaers, E. González-Romero, M. S. Robles, Nicola Colonna, G. Giubrone, A. R. García, Vasilis Vlachoudis, M. Brugger, M. Diakaki, I. Duran, G. Cortes, D. Tarrío, R. Dressler, M. J. Vermeulen, H. Leeb, V. Variale, J. Perkowski, A. Mallick, G. Vannini, M. Weigand, F. Belloni, C. Carrapiço, E. Mendoza, Rene Reifarth, J. M. Quesada, L. Tassan-Got, and L. Audouin

Subjects
Physics, 010308 nuclear & particles physics, Gamma ray, Nuclear data, Scintillator, 7. Clean energy, 01 natural sciences, Resonance (particle physics), Nuclear physics, Neutron capture, Nuclear reactor core, 0103 physical sciences, Neutron cross section, Neutron, 010306 general physics
Abstract

The aim of this work is to provide a precise and accurate measurement of the U238(n,γ) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross section of U238 should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n-TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these U238(n,γ) measurements performed at the n-TOF CERN facility are presented in this work. The γ-ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher.

Published
2017

72. Coulomb breakup of neutron-rich 29,30Na isotopes near the island of inversion

Author

Håkan Johansson, Herbert A. Simon, T. Kröll, J. Marganiec, Helmut Weick, Anisur Rahaman, O. Ershova, C. Caesar, Stefan Typel, Thomas Nilsson, Ushasi Datta, G. Münzenberg, D. Yakorev, Yasuhiro Togano, F. Wamers, J. Taylor, J. S. Winfield, Y. Leifels, Nasser Kalantar-Nayestanaki, A. Najafi, C. Scheidenberger, L. M. Fraile, K. Boretzky, Thomas Aumann, T. Le Bleis, Björn Jonson, R. Krücken, D. Cortina-Gil, V. Ricciardi, S. Beceiro-Novo, C. Nociforo, Christoph Langer, V. Volkov, G. de Angelis, J. Kurcewicz, H. Emling, B. V. Carlson, W. N. Catford, Catherine Rigollet, P. Díaz Fernández, D. M. Rossi, Andreas Wagner, D. Gonzalez-Diaz, Mario Weigand, Marielle Chartier, Stefanos Paschalis, M. Zoric, Rene Reifarth, Heiko Scheit, Ralf Plag, Hans Geissel, S. Chakraborty, V. Panin, and Research unit Nuclear & Hadron Physics

Subjects
Nuclear and High Energy Physics, ground state configuration, COLLISIONS, Nuclear Theory, neutron-rich nulei, RIB, Coulomb breakup, ground state configuration, spectroscopic factor, island of inversion, FOS: Physical sciences, Coulomb excitation, 01 natural sciences, Nuclear Theory (nucl-th), Atomic orbital, 0103 physical sciences, Coulomb, Coulomb breakup, Neutron, Nuclear Experiment (nucl-ex), spectroscopic factor, 010306 general physics, Nuclear Experiment, Physics, Valence (chemistry), neutron-rich nulei, NUCLEI, 010308 nuclear & particles physics, Island of inversion, RIB, island of inversion, Coulomb-dissociation 29Na 30Na breakup spin parity, SHELL-MODEL, Atomic physics, Nucleon, Ground state
Abstract

First results are reported on the ground state configurations of the neutron-rich $^{29,30}$Na isotopes, obtained via Coulomb dissociation (CD) measurements as a method of the direct probe. The invariant mass spectra of those nuclei have been obtained through measurement of the four-momentum of all decay products after Coulomb excitation on a $^{208}Pb$ target at energies of 400-430 MeV/nucleon using FRS-ALADIN-LAND setup at GSI, Darmstadt. Integrated Coulomb-dissociation cross-sections (CD) of 89 $(7)$ mb and 167 $(13)$ mb up to excitation energy of 10 MeV for one neutron removal from $^{29}$Na and $^{30}$Na respectively, have been extracted. The major part of one neutron removal, CD cross-sections of those nuclei populate core, in its' ground state. A comparison with the direct breakup model, suggests the predominant occupation of the valence neutron in the ground state of $^{29}$Na${(3/2^+)}$ and $^{30}$Na${(2^+)}$ is the $d$ orbital with small contribution in the $s$-orbital which are coupled with ground state of the core. The ground state configurations of these nuclei are as $^{28}$Na$_{gs (1^+)\otimes\nu_{s,d}$ and $^{29}$Na$_{gs}(3/2^+)\otimes\nu_{ s,d}$, respectively. The ground state spin and parity of these nuclei, obtained from this experiment are in agreement with earlier reported values. The spectroscopic factors for the valence neutron occupying the $s$ and $d$ orbitals for these nuclei in the ground state have been extracted and reported for the first time. A comparison of the experimental findings with the shell model calculation using MCSM suggests a lower limit of around 4.3 MeV of the sd-pf shell gap in $^{30}$Na., Comment: Modified version of the manuscript is accepted for publication in Journal of Physics G, Jan., 2017

Published
2017

73. β-particle energy-summing correction for β-delayed proton emission measurements

Author

G. F. Grinyer, Christoph Langer, Z. Meisel, Karl Smith, H. L. Crawford, Richard H. Cyburt, Fernando Montes, M.G. Del Santo, Hendrik Schatz, Grand Accélérateur National d'Ions Lourds (GANIL), 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
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, β-delayed proton emission, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Shape of the distribution, Atomic, Nuclear physics, Recoil, Particle and Plasma Physics, Affordable and Clean Energy, 0103 physical sciences, medicine, Nuclear, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], DSSD, Proton emission, 010306 general physics, Nuclear Experiment, Instrumentation, GEANT4, Physics, 010308 nuclear & particles physics, Detector, Molecular, Nuclear & Particles Physics, Other Physical Sciences, medicine.anatomical_structure, Decay energy, Measured depth, Atomic physics, Nucleus, Astronomical and Space Sciences
Abstract

A common approach to studying $\beta$-delayed proton emission is to measure the energy of the emitted proton and corresponding nuclear recoil in a double-sided silicon-strip detector (DSSD) after implanting the $\beta$-delayed proton emitting ($\beta$p) nucleus. However, in order to extract the proton-decay energy, the measured energy must be corrected for the additional energy implanted in the DSSD by the $\beta$-particle emitted from the $\beta$p nucleus, an effect referred to here as $\beta$-summing. We present an approach to determine an accurate correction for $\beta$-summing. Our method relies on the determination of the mean implantation depth of the $\beta$p nucleus within the DSSD by analyzing the shape of the total (proton + recoil + $\beta$) decay energy distribution shape. We validate this approach with other mean implantation depth measurement techniques that take advantage of energy deposition within DSSDs upstream and downstream of the implantation DSSD., Comment: Published in Nuclear Instruments and Methods in Physics Research A

Published
2017

74. Measurement of the 241Am neutron capture cross section at the n-TOF facility at CERN

Author

C. Carrapiço, Tanja Heftrich, Rene Reifarth, I. Duran, M. S. Robles, A. Mengoni, M. P. W. Chin, V. Ketlerov, F. Roman, Javier Praena, E. Leal-Cidoncha, M. Mastromarco, Anton Wallner, Srinivasan Ganesan, J. Balibrea, Mario Barbagallo, F. Mingrone, J. Andrzejewski, C. Paradela, L. Audouin, A. Riego-Perez, M. Diakaki, D. Cano-Ott, P. Gurusamy, E. González, F. Käppeler, Jeri Kroll, C. Eleftheriadis, Thomas Rauscher, D. Karadimos, C. Domingo-Pardo, G. Vannini, Stefan Schmidt, A. Goverdovski, Vittorio Boccone, J. M. Quesada, L. Tassan-Got, Iris Dillmann, A. Hernández-Prieto, A. K. Saxena, Arnaud Ferrari, A. R. García, M. Brugger, L. S. Leong, Jan Heyse, M. Sabaté-Gilarte, A. Manousos, Mario Weigand, J. Billowes, G. Tagliente, F. Cerutti, F. Gunsing, M. Krtička, Tatsuya Katabuchi, P. E. Koehler, M. Fernandez-Ordonez, Cristian Massimi, P. V. Sedyshev, M. Licata, G. Giubrone, A. J. M. Plompen, F. Bečvář, T. Martinez, V. Khryachkov, Roberto Losito, T. Ware, P. M. Milazzo, F. Gramegna, M. Kokkoris, C. Weiss, E. Griesmayer, G. Cortes, E. Mendoza, D. Tarrío, J. Marganiec, S. Andriamonje, M. Mirea, Peter Schillebeeckx, Carlos Guerrero, V. Furman, T. J. Wright, N. Dzysiuk, M. A. Cortés-Giraldo, E. Chiaveri, S. Heinitz, F. Calviño, P. F. Mastinu, H. Leeb, J. Perkowski, C. Rubbia, V. Bécares, Petar Žugec, K. Fraval, S. Altstadt, M. B. Gómez-Hornillos, Christoph Langer, C. Lampoudis, A. Pavlik, A. Tsinganis, J. L. Tain, Nicola Colonna, E. Jericha, Vasilis Vlachoudis, Ariel Tarifeño-Saldivia, Dorothea Schumann, J. A. Ryan, R. Sarmento, R. Vlastou, J. Lerendegui-Marco, P. Vaz, E. Berthoumieux, Alberto Ventura, I. F. Gonçalves, D. G. Jenkins, Fabio Belloni, W. Mondelaers, V. Variale, Roberto Versaci, C. Lederer, Damir Bosnar, Y. Kadi, M. J. Vermeulen, B. Berthier, S. Valenta, Marco Calviani, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), n_TOF, Mengoni, A., 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), Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Mendoza, E., Cano-Ott, D., Altstadt, S., Andriamonje, S., Andrzejewski, J., Audouin, L., Balibrea, J., Bécares, V., Barbagallo, M., Bečvář, F., Belloni, F., Berthier, B., Berthoumieux, E., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviño, F., Calviani, M., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Diakaki, M., Dillmann, I., Domingo-Pardo, C., Durán, I., Dzysiuk, N., Eleftheriadis, C., Fernández-Ordóñez, M., Ferrari, A., Fraval, K., Furman, V., Gómez-Hornillos, M.B., Ganesan, S., García, A.R., Giubrone, G., Gonçalves, I.F., González, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Katabuchi, T., Ketlerov, V., Khryachkov, V., Koehler, P., Kokkoris, M., Kroll, J., Krtička, M., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L.S., Lerendegui-Marco, J., Licata, M., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A.J.M., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M., Roman, F., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vermeulen, M.J., Versaci, R., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiss, C., Wright, T., and Ž Ugec, P.

Subjects
Nuclear reaction, Nuclear transmutation, nTOF, QC1-999, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Physics and Astronomy (all), Cross section (physics), Nuclear reactors, Reactors nuclears, 0103 physical sciences, CERN, Neutron cross section, Nuclear Physics - Experiment, ddc:530, 010306 general physics, Absorption (electromagnetic radiation), Physics, Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Large Hadron Collider, Cross section, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, Calorimeter
Abstract

New neutron cross section measurements of minor actinides have been performed recently in order to reduce the uncertainties in the evaluated data, which is important for the design of advanced nuclear reactors and, in particular, for determining their performance in the transmutation of nuclear waste. We have measured the 241 Am(n,γ) cross section at the n TOF facility between 0.2 eV and 10 keV with a BaF2 Total Absorption Calorimeter, and the analysis of the measurement has been recently concluded. Our results are in reasonable agreement below 20 eV with the ones published by C. Lampoudis et al. in 2013, who reported a 22% larger capture cross section up to 110 eV compared to experimental and evaluated data published before. Our results also indicate that the 241 Am(n,γ) cross section is underestimated in the present evaluated libraries between 20 eV and 2 keV by 25%, on average, and up to 35% for certain evaluations and energy ranges. Plan Nacional I+D+I FPA2014-53290-C2-1 Comisión Europea, ANDES FP7- 249671 Comisión Europea, CHANDA FP7-605203

Published
2017

75. Constraining the rp-process by measuring 23Al(d,n)24Si with GRETINA and LENDA at NSCL

Author

J. C. Zamora, Heather Crawford, Peter Bender, Daniel Bazin, Fernando Montes, Sara Ayoub, D. Weisshaar, Jaclyn Schmitt, Panagiotis Gastis, Eric Deleeuw, Christoph Langer, Brandon Elman, Rene Reifarth, C. Wolf, S. Lipschutz, Alex Brown, Justin Browne, Jorge Pereira, Alexandra Gade, Wei Jia Ong, Philip Woods, C. Sullivan, Brenden Longfellow, R. Titus, Konrad Schmidt, Filomena Nunes, Remco Zegers, Sunghoon Ahn, S. Fiebiger, T. Poxon-Pearson, G. Perdikakis, and Hendrik Schatz

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, rp-process, Tracking (particle physics), 01 natural sciences, 7. Clean energy, Nuclear physics, Reaction rate, Superconducting cyclotron, Excited state, 0103 physical sciences, Neutron detection, Neutron, 010306 general physics, Nuclear Experiment, 010303 astronomy & astrophysics, Energy (signal processing)
Abstract

The 23 Al(p, γ)24 Si 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 24 Si. 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 23 Al(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 24 Si recoils. As a proof of principle to show the feasibility of this concept the Q-value spectrum of 22 Mg(d,n)23 Al is reconstructed.

Published
2017

76. Neutron spectroscopy of 26Mg states: Constraining the stellar neutron source 22Ne(α, n)25Mg

Author

D. Tarrío, C. Paradela, A. Manousos, Rene Reifarth, J. Marganiec, P. Schillebeeckx, M. A. Cortés-Giraldo, P. F. Mastinu, S. Valenta, Marco Calviani, Marco Pignatari, F. Mingrone, J. Andrzejewski, Srinivasan Ganesan, Alfredo Ferrari, M. Mastromarco, Petar Žugec, Carlo Rubbia, A. Mallick, J. M. Quesada, L. Tassan-Got, J. L. Tain, C. Lampoudis, F. Cerutti, G. Vannini, A. Tsinganis, Mario Barbagallo, C. Carrapiço, Sergio Cristallo, Anton Wallner, D. Schumann, R. Vlastou, P. Vaz, J. Billowes, Nicola Colonna, L.S. Leong, M. Krtička, F. Calviño, A. R. García, S. Altstadt, E. Jericha, Damir Bosnar, Y. Kadi, Vasilis Vlachoudis, Christoph Langer, T. Martinez, N. Kivel, Paolo Finocchiaro, D. M. Castelluccio, P. E. Koehler, A. J. M. Plompen, Alberto Ventura, M. S. Robles, R. Losito, C. Weiß, T. Wright, M. Brugger, Javier Praena, S. Lo Meo, V. Bécares, I. Van Rijs, M. Weigand, M. J. Vermeulen, F. Belloni, G. Tagliente, Alberto Mengoni, A. Musumarra, Stefan Kopecky, P. M. Milazzo, D. G. Jenkins, M. Kokkoris, K. Fraval, A. Hernández-Prieto, M. Diakaki, Luigi Cosentino, G. Giubrone, E. Leal-Cidoncha, F. Bečvář, C. Eleftheriadis, Giulia Clai, F. Käppeler, E. Chiaveri, I. Duran, D. Cano-Ott, I. F. Gonçalves, Thomas Rauscher, A. K. Saxena, R. Dressler, R. Wynants, A. Pavlik, T. Ware, A. Riego, C. Domingo-Pardo, E. Griesmayer, M. Sabaté-Gilarte, D. Karadimos, L. Audouin, Carlos Guerrero, C. Lederer, E. González-Romero, M. P. W. Chin, Jeri Kroll, R. Sarmento, S. Schmidt, M. Mirea, L. Piersanti, E. Berthoumieux, W. Mondelaers, V. Variale, E. Mendoza, S. Bisterzo, H. Leeb, J. Perkowski, F. Gunsing, Cristian Massimi, G. Cortes, ITA, GBR, FRA, DEU, ESP, AUS, AUT, BEL, JPN, GRC, IND, CZE, CHE, Massimi, C., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Bisterzo, S., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Castelluccio, D.M., Cerutti, F., Chiaveri, E., Cosentino, L., Chin, M., Clai, G., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cristallo, S., Diakaki, M., Domingo-Pardo, C., Duran, I., Dressler, R., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A.R., Giubrone, G., Gonçalves, I.F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Hernández-Prieto, A., Jenkins, D.G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Kopecky, S., Krtička, M., Kroll, J., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L.S., Lo Meo, S., Losito, R., Mallick, A., Manousos, A., Marganiec, J., Martínez, T., Mastinu, P.F., Mastromarco, M., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Musumarra, A., Paradela, C., Pavlik, A., Perkowski, J., Pignatari, M., Piersanti, L., Plompen, A., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego, A., Robles, M.S., Rubbia, C., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J.L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Van Rijs, I., Variale, V., Vaz, P., Ventura, A., Vermeulen, M.J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., Wynants, R., Wright, T., Žugec, P., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, 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 de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, n_TOF, Institut de Physique Nucléaire d'Orsay (IPNO), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, and 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)

Subjects
Capture, nucl-ex, Proce, 01 natural sciences, Espectroscòpia atòmica, Stellar nucleosynthesis, CERN, Neutron spectroscopy, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, 010303 astronomy & astrophysics, Physics, Cross section, s Process, α+22Ne, lcsh:QC1-999, Neutron temperature, PRIRODNE ZNANOSTI. Fizika, Atomic spectroscopy, Excited state, Atomic physics, s Process, α+22Ne, Neutron spectroscopy, Nuclear and High Energy Physics, nTOF, Neutron, [formula omitted]Ne, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Neutron spectroscopy, s Process, α+22Ne, Nuclear and High Energy Physics, Nuclear physics, Experimental, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, 0103 physical sciences, Nuclear Physics - Experiment, Spin (physics), α+22 Ne, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, NATURAL SCIENCES. Physics, Neutron source, Neutron spectroscopy, s Process, α+22Ne, α+Ne, s-process, lcsh:Physics
Abstract

This work reports on accurate, high-resolution measurements of the $^{25}$Mg($n, \gamma$)$^{26}$Mg and $^{25}$Mg($n, tot$) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved $^{25}$Mg($n, \gamma$)$^{26}$Mg parametrization. The relevant resonances for $n+^{25}$Mg were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in $^{26}$Mg. With this information experimental upper limits of the reaction rates for $^{22}$Ne($\alpha, n$)$^{25}$Mg and $^{22}$Ne($\alpha, \gamma$)$^{26}$Mg were established, potentially leading to a significantly higher ($\alpha, n$)/($\alpha, \gamma$) ratio than previously evaluated. The impact of these results have been studied for stellar models in the mass range 2 to 25 $M_{\odot}$., Comment: Preprint, 6 pages, 5 figures

Published
2017

77. Measurement of the neutron capture cross section of the fissile isotope 235U with the CERN n-TOF total absorption calorimeter and a fission tagging based on micromegas detectors

Author

E. Jericha, Dorothea Schumann, J. A. Ryan, C. Paradela, G. Cortes, M. Mastromarco, V. Khryachkov, Rugard Dressler, P. M. Milazzo, M. A. Cortés-Giraldo, D. Tarrío, Rene Reifarth, A. Goverdovski, L. Audouin, C. Rubbia, J. Balibrea-Correa, A. Tsinganis, M. S. Robles, Nicola Colonna, Anton Wallner, Stefan Schmidt, Javier Praena, P. V. Sedyshev, Vasilis Vlachoudis, Jeri Kroll, S. Altstadt, G. Tagliente, P. E. Koehler, Srinivasan Ganesan, M. B. Gómez-Hornillos, Christoph Langer, K. Fraval, Petar Žugec, Mario Weigand, M. Diakaki, A. Mallick, J. M. Quesada, D. Cano-Ott, V. Bécares, G. Vannini, L. Tassan-Got, E. Mendoza, A. J. M. Plompen, G. Giubrone, C. Carrapiço, L. S. Leong, Mario Barbagallo, Carlos Guerrero, M. Krtička, A. Manousos, J. L. Tain, S. Heinitz, C. Weiss, F. Mingrone, J. Andrzejewski, V. Boccone, F. Bečvář, F. Cerutti, Niko Kivel, I. Duran, M. Sabaté-Gilarte, C. Lederer, C. Lampoudis, Roberto Losito, M. Licata, T. Martinez, A. Pavlik, Peter Schillebeeckx, C. Domingo-Pardo, Kathrin Göbel, J. Marganiec, M. Mirea, J. Lerendegui-Marco, Tatsuya Katabuchi, E. Chiaveri, P. F. Mastinu, F. Käppeler, Jan Heyse, R. Sarmento, D. G. Jenkins, P. Vaz, R. Vlastou, F. Calviño, H. Leeb, A. Hernández-Prieto, Alberto Ventura, E. Berthoumieux, J. Perkowski, F. Gunsing, I. F. Gonçalves, Cristian Massimi, W. Mondelaers, E. González, V. Furman, T. J. Wright, V. Variale, Tanja Heftrich, A. Riego-Perez, Fabio Belloni, M. Kokkoris, A. K. Saxena, Arnaud Ferrari, J. Billowes, Ariel Tarifeño-Saldivia, S. Valenta, Marco Calviani, M. J. Vermeulen, E. Leal-Cidoncha, C. Eleftheriadis, Damir Bosnar, Thomas Rauscher, Y. Kadi, D. Karadimos, T. Ware, E. Griesmayer, A. R. García, M. Brugger, A. Mengoni, M. P. W. Chin, V. Ketlerov, Mengoni, A., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Institut de Physique Nucléaire d'Orsay (IPNO), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, 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), Balibrea-Correa, J., Mendoza, E., Cano-Ott, D., Krtička, M., Altstadt, S., Andrzejewski, J., Audouin, L., Bécares, V., Barbagallo, M., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviño, F., Calviani, M., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Durán, I., Eleftheriadis, C., Ferrari, A., Fraval, K., Furman, V., Göbel, K., Guerrero, C., Gómez-Hornillos, M.B., Ganesan, S., García, A.R., Giubrone, G., Gonçalves, I.F., González, E., Goverdovski, A., Griesmayer, E., Gunsing, F., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Katabuchi, T., Ketlerov, V., Khryachkov, V., Kivel, N., Koehler, P., Kokkoris, M., Kroll, J., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L.S., Lerendegui-Marco, J., Licata, M., Losito, R., Mallick, A., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A.J.M., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vermeulen, M.J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiss, C., Wright, T., Žugec, P., Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group

Subjects
Nuclear reaction, nTOF, Fission, Physics::Instrumentation and Detectors, QC1-999, Nuclear Theory, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Physics and Astronomy (all), 0103 physical sciences, CERN, Neutron cross section, ddc:530, Nuclear Physics - Experiment, 010306 general physics, Nuclear Experiment, Physics, Neutrons, Radioisotopes, Isòtops radioactius, Calorimeter (particle physics), Fissile material, cross section, 010308 nuclear & particles physics, Nuclear data, MicroMegas detector
Abstract

The accuracy on neutron capture cross section of fissile isotopes must be improved for the design of future nuclear systems such as Gen-IV reactors and Accelerator Driven Systems. The High Priority Request List of the Nuclear Energy Agency, which lists the most important nuclear data requirements, includes also the neutron capture cross sections of fissile isotopes such as 233,235U and 239,241Pu. A specific experimental setup has been used at the CERN n TOF facility for the measurement of the neutron capture cross section of 235U by a set of micromegas fission detectors placed inside a segmented BaF2 Total Absorption Calorimeter. Plan Nacional de I+D+I Física de particulas FPA2014-53290-C2-1

Published
2017

78. Reactor neutrons in nuclear astrophysics

Author

Jan Glorius, Kathrin Göbel, Ulli Köster, Tanja Heftrich, Michael Jentschel, Rene Reifarth, Christoph Langer, Mario Weigand, Beatriz Jurado, F. Käppeler, Yuri A. Litvinov, and ND 2016: International Conference on Nuclear Data for Science and Technology

Subjects
Physics, Radionuclide, Isotope, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, 01 natural sciences, 7. Clean energy, Ion, Nuclear physics, 0103 physical sciences, Nuclear astrophysics, ddc:530, Neutron, Nuclear Experiment, 010303 astronomy & astrophysics, Storage ring
Abstract

The huge neutron fluxes offer the possibility to use research reactors to produce isotopes of interest, which can be investigated afterwards. An example is the half-lives of long-lived isotopes like 129 I. A direct usage of reactor neutrons in the astrophysical energy regime is only possible, if the corresponding ions are not at rest in the laboratory frame. The combination of an ion storage ring with a reactor and a neutron guide could open the path to direct measurements of neutron-induced cross sections on short-lived radioactive isotopes in the astrophysically interesting energy regime.

Published
2017

79. Studies at the border between nuclear and atomic physics: Weak decays of highly charged ions

Author

Iris Dillmann, P. Kienle, V.P. Shevelko, F. C. Ozturk, Xiao-Lin Tu, X. L. Yan, P. J. Woods, X.W. Ma, Jan Glorius, Yu. A. Litvinov, U. Spillmann, H S Xu, X. C. Chen, NucAR Collaborations, M. Steck, Sergey Litvinov, Zygmunt Patyk, C. Brandau, P. M. Walker, F. Nolden, Robert E. Grisenti, P. M. Hillenbrand, Y. H. Zhang, Ilima, Sparc, Twbd, Hans Geissel, Paul Alois Buhler, S. Hagmann, Miodrag K. Pavicevic, C. Kozhuharov, Thomas Stöhlker, B S Gao, C. Trageser, Y Yamaguchi, Xiaojuan Zhou, R. Sánchez, Takayuki Yamaguchi, F. Suzaki, Toshio Suzuki, Klaus Blaum, A. Ozawa, Thomas Faestermann, Min Wang, S. Yu. Torilov, Gregory Lane, M. S. Sanjari, Dinko Atanasov, R. B. Cakirli, F. Bosch, Takashi Ohtsubo, Nicolas Winckler, Helmut Weick, D. H. Schneider, Roman Gernhäuser, Michael Lestinsky, Claudia Lederer-Woods, Martino Trassinelli, Christoph Langer, M. A. Najafi, A. Gumberidze, Tomohiro Uesaka, N. Petridis, Bao-Hua Sun, Rene Reifarth, and for the ILIMA, SPARC, TWBD, and NucAR Collaborations

Subjects
Physics, History, 010308 nuclear & particles physics, 0103 physical sciences, ddc:530, Präzisionsexperimente - Abteilung Blaum, Atomic physics, 010306 general physics, 01 natural sciences, Computer Science Applications, Education, Ion
Abstract

Journal of physics / Conference Series 875, 012008 (2017). doi:10.1088/1742-6596/875/2/012008, Published by IOP Publ., Bristol

Published
2017

80. Constraining astrophysical reaction rates: using the storage rings at FAIR/GSI

Author

Jan Glorius, Christoph Langer, Sergey Litvinov, Yuri A. Litvinov, Rene Reifarth, and Z. Slavkovská

Subjects
Physics, Astrophysical Processes, Breakout, 010308 nuclear & particles physics, QC1-999, Branching (polymer chemistry), 01 natural sciences, Ion, Nuclear physics, Reaction rate, 0103 physical sciences, ddc:530, 010303 astronomy & astrophysics, Storage ring
Abstract

Nuclear Physics in Astrophysics VIII, NPA8 2017, Catania, Italy, 18 Jun 2017 - 23 Jun 2017; The European physical journal / Web of Conferences 165, 01033 (2017). doi:10.1051/epjconf/201716501033, Ion optical calculations for a storage ring at the present GSI facility for direct proton-induced reactions relevant for different astrophysical processes are presented. As an example case, the 59Cu(p,γ) and 59Cu(p,α) reactions are shown. The branching of these two reactions is important in X-ray burst scenarios, since it determines the breakout out of the major 56Ni waiting point., Published by EDP Sciences, Les Ulis

Published
2017

81. Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry

Author

Pamela W. Schaefer, Matthias Lutz, Norbert Frey, Olav Jansen, M. Eden, Marcus Both, C. Kühl, H. Harders, Christoph Langer, and B. Sattler

Subjects
Male, medicine.medical_specialty, Time Factors, Cardiac Volume, Heart Ventricles, Magnetic Resonance Imaging, Cine, Computed tomography, Ventricular Function, Left, Internal medicine, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, cardiovascular diseases, Neuroradiology, Late enhancement, medicine.diagnostic_test, business.industry, Ultrasound, Hypertrophic cardiomyopathy, Reproducibility of Results, Magnetic resonance imaging, Interventional radiology, General Medicine, Cardiomyopathy, Hypertrophic, Middle Aged, medicine.disease, cardiovascular system, Cardiology, Female, Radiology, Tomography, X-Ray Computed, business, Nuclear medicine, Body mass index
Abstract

Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM.N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR.The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p 0.05). In the group with good LV-contrast assessment of LV-MM resulted in 147.4 ± 64.8 g in leMDCT vs. 147.1 ± 65.9 in CMR (p 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r 0.9).LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in 90% of the cases.• LeMDCT of relatively low contrast allows for LV planimetry in HCM. • The correlation of leMDCT-based LV volumetry with gold-standard CMR was excellent (r 0.9). • LeMDCT requires approximately 2.0mL/kgBW of dye to achieve acceptable contrast.

Published
2014

82. Simulation and Fabrication of Silicon Field Emission Cathodes for Cold Electron Sources

Author

Rupert Schreiner, Christoph Langer, Florian Dams, Christian Prommesberger, and R. Lawrowski

Subjects
Thermal oxidation, Fabrication, Materials science, Silicon, Physics::Instrumentation and Detectors, business.industry, General Engineering, chemistry.chemical_element, Substrate (electronics), Curvature, Aspect ratio (image), Field electron emission, Optics, chemistry, Reactive-ion etching, business
Abstract

We report on the simulation and fabrication of nanostructured silicon surfaces for field emission (FE) applications, e.g. ionization sensors and x-ray tubes. For the design and optimization of field-emitting silicon structures, the influence of the geometric parameters like tip height, apex radius, aperture angle and curvature shape on the field enhancement factor was investigated by simulation using finite element method. A universal geometric model which describes the real geometry of our silicon structures sufficiently accurate was taken for modeling a variety of different silicon tip structures as well as ridge structures. While a high dependency of the field enhancement on the aspect ratio and the aperture angle was found, the simulations show that the elliptic curvature affects the field enhancement only marginally. Finally, an improved process for fabrication of such silicon structures on n-type as well as p-type substrate is described, using reactive ion etching with adjustable anisotropy, wet thermal oxidation and wet etching.

Published
2014

83. Compact and Energy-Efficient Field Emission Cathodes for Sensor Applications

Author

Christian Prommesberger, Florian Dams, Christoph Langer, and Rupert Schreiner

Subjects
Materials science, Silicon, Physics::Instrumentation and Detectors, business.industry, Hybrid silicon laser, General Engineering, chemistry.chemical_element, Nanotechnology, Cathode, law.invention, Field electron emission, Semiconductor, chemistry, law, Optoelectronics, Wafer, business, Electronic circuit, Common emitter
Abstract

We report on miniaturized silicon field emitter arrays for the application in compact and energy-saving vacuum-microelectronic devices, e.g. sensors or x-ray tubes. Since standard silicon semiconductor technology has been used for the fabrication, they may be easily integrated with other silicon based circuits and devices on the same chip. The silicon tip geometry and the operating conditions were optimized in order to obtain highly uniform and stable electron field emission from large area cathode arrays. A series of uniform hexagonal tip arrays containing each 547 tips were fabricated and characterized. The electron emission properties of both individual tips as well as of complete emitter arrays were investigated. A saturation level in the voltage-current characteristics was found, which can be explained by the limitation of the supply of electrons due to the p-type silicon wafer material. When operating the arrays in the current saturation regime at an emission current of ~ 1 nA per tip, a highly stable and low noise emission can be observed.

Published
2014

84. Measurement of the 241Am and the 243Am Neutron Capture Cross Sections at the n_TOF Facility at CERN

Author

I. F. Gonçalves, R. Versaci, M. Kokkoris, Petar Žugec, Fabio Belloni, Arnaud Ferrari, F. Käppeler, Damir Bosnar, G. Vannini, Rugard Dressler, Jeri Kroll, F. Gunsing, Y. Kadi, N. Kivel, A. Riego, A. Tsinganis, G. Cortes, F. Cerutti, F. Mingrone, D. Tarrío, Nicola Colonna, L.S. Leong, Cristian Massimi, P. Gurusamy, S. Valenta, P. E. Koehler, R. Sarmento, Marco Calviani, J. Andrzejewski, A. Manousos, K. Fraval, C. Eleftheriadis, Vasilis Vlachoudis, M. Krtička, F. Calviño, C. Lederer, J. L. Tain, Thomas Rauscher, T. Martinez, J. Marganiec, Javier Praena, W. Mondelaers, D. Karadimos, Carlos Guerrero, M. Mirea, C. Paradela, T. J. Wright, L. Audouin, G. Tagliente, I. Duran, V. Variale, E. González-Romero, J. Billowes, E. Chiaveri, M. Meaze, A. J. M. Plompen, M. P. W. Chin, M. J. Vermeulen, H. Leeb, P. F. Mastinu, Marco Pignatari, F. Roman, J. Perkowski, T. Ware, Roberto Losito, D. Cano-Ott, M. Diakaki, E. Griesmayer, R. Vlastou, M. Mastromarco, A. R. García, Mario Weigand, G. Giubrone, C. Carrapiço, Anton Wallner, M. Brugger, M. B. Gómez-Hornillos, E. Berthoumieux, Christoph Langer, Alberto Mengoni, C. Rubbia, V. Bécares, E. Jericha, Dorothea Schumann, C. Weiß, S. Altstadt, F. Bečvář, P. M. Milazzo, E. Mendoza, Peter Schillebeeckx, N. Dzysiuk, Gunther Korschinek, A. Pavlik, C. Domingo-Pardo, P. Vaz, M. A. Cortés-Giraldo, D. G. Jenkins, A. Ventura, Srinivasan Ganesan, Rene Reifarth, Mario Barbagallo, Stefan Schmidt, Vittorio Boccone, J. M. Quesada, L. Tassan-Got, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, Ventura, A., and Mengoni, A.

Subjects
Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Nuclear reaction, Nuclear and High Energy Physics, Large Hadron Collider, Materials science, Cross section, Calorimeter (particle physics), Physics::Instrumentation and Detectors, TOF, Capture, Nuclear data, Neutron, Neutons, Nuclear physics, Neutron capture, Cross section (physics), 241Am, 243Am, neutron capture, n_TOF, Physics::Accelerator Physics, Nuclear reactions, Nuclear Experiment, Data reduction
Abstract

The capture cross sections of 241Am and 243Am were measured at the n_TOF facility at CERN in the epithermal energy range with a BaF2 Total Absorption Calorimeter. A preliminary analysis of the 241Am and a complete analysis of the 243Am measurement, including the data reduction and the resonance analysis, have been performed., JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Published
2014

85. Hypertrophic cardiomyopathy in cardiac CT: a validation study on the detection of intramyocardial fibrosis in consecutive patients

Author

M. Eden, Christian Prinz, Marcus Both, Dieter Horstkotte, Lothar Faber, Norbert Frey, Matthias Lutz, M. Lüdde, C. Gierloff, Wolfgang Burchert, Christoph Langer, and M. Hohnhorst

Subjects
Male, medicine.medical_specialty, Iohexol, Cardiomyopathy, Contrast Media, Sudden cardiac death, Fibrosis, Internal medicine, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, cardiovascular diseases, Cardiac imaging, medicine.diagnostic_test, business.industry, Myocardium, Iopromide, Hypertrophic cardiomyopathy, Reproducibility of Results, Heart, Magnetic resonance imaging, Gold standard (test), Cardiomyopathy, Hypertrophic, Middle Aged, medicine.disease, Radiographic Image Enhancement, cardiovascular system, Cardiology, Female, Tomography, X-Ray Computed, Cardiology and Cardiovascular Medicine, business, medicine.drug
Abstract

Hypertrophic Cardiomyopathy (HCM) confers a 4-5 %/year-risk for sudden cardiac death. Intramyocardial fibrosis (IF) is associated with this risk. The gold standard of IF visualization is cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE-CMR). In view of a number of CMR-limitations the hypothesis of this study was that late enhanced multi-slice computed tomography (leMDCT) enables demonstration of late enhancement (LE) indicating IF. In a prospective single-center validation study leMDCT research-scans were exclusively performed for IF-imaging in HCM-patients not including non-invasive coronary angiography during first-pass (64-slice; 80 kV; Iopromide, 150 mL, injected 7 min before scanning). Applying a 17-segment-polar-map short cardiac axis views (multiplanar reformations; 5 mm slice thickness) were analysed in order to exclude/detect, localize and measure LE practicing the manual quantification method if present. Finally, leMDCT and LGE-CMR data were unblinded for intermodal correlation. We included n = 24 patients consecutively (64.0 ± 14.5 years of age). LE was demonstrated by LGE-CMR in n = 14/24 patients (prevalence 58 %). Patient- and segment-based sensitivity in leMDCT was 100 and 68 %, respectively. In leMDCT tissue density of LE was 142 ± 51 versus 89.9 ± 19.3 HU in remote myocardium (p0.001). Signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) appeared to be 7.3 ± 3.3 and 2.3 ± 1, respectively. Sizing of LE-area gave 2.2 ± 1.4 cm(2) in leMDCT versus 2.9 ± 2.4 cm(2) in LGE-CMR (r = 0.93). Intra-/interobserver variability was assessed with an accuracy of 0.36 cm(2) (r = 0.91) and 0.47 cm(2) (r = 0.82), respectively. In consecutive HCM patients leMDCT can reliably detect intramyocardial fibrosis marked by LE. In view of a comparatively low SNR and CNR leMDCT may alternatively be applied in case of CMR contraindications.

Published
2014

86. Improvement of Homogeneity and Aspect Ratio of Silicon Tips for Field Emission by Reactive-Ion Etching

Author

Christian Prommesberger, R. Lawrowski, Rupert Schreiner, Florian Dams, and Christoph Langer

Subjects
Fabrication, Materials science, Article Subject, Silicon, business.industry, General Engineering, chemistry.chemical_element, Field electron emission, chemistry, Homogeneity (physics), lcsh:TA401-492, Optoelectronics, lcsh:Materials of engineering and construction. Mechanics of materials, General Materials Science, Wafer, Undercut, Reactive-ion etching, Anisotropy, business
Abstract

The homogeneity of emitters is very important for the performance of field emission (FE) devices. Reactive-ion etching (RIE) and oxidation have significant influences on the geometry of silicon tips. The RIE influences mainly the anisotropy of the emitters. Pressure has a strong impact on the anisotropic factor. Reducing the pressure results in a higher anisotropy, but the etch rate is also lower. A longer time of etching compensates this effect. Furthermore an improvement of homogeneity was observed. The impact of uprating is quite low for the anisotropic factor, but significant for the homogeneity. At low power the height and undercut of the emitters are more constant over the whole wafer. The oxidation itself is very homogeneous and has no observable effect on further variation of the homogeneity. This modified fabrication process allows solving the problem of inhomogeneity of previous field emission arrays.

Published
2014

87. Quasi-free proton knockout from 12C on carbon target at 398 MeV/u

Author

J. Taylor, D. M. Rossi, Christoph Langer, Helmut Weick, Håkan T Johansson, Marielle Chartier, Michael Heil, H. Scheit, M. Holl, Stefanos Paschalis, Björn Jonson, T. Le Bleis, Thomas Aumann, H. Alvarez-Pol, Carlos A. Bertulani, D. Cortina-Gil, Y. Aksyutina, C. Caesar, Thomas Nilsson, Herbert A. Simon, F. Wamers, O. Kiselev, O. Ershova, Hans Geissel, Roy Crawford Lemmon, C. Wimmer, V. Panin, L. V. Chulkov, K. Boretzky, Ralf Plag, Joachim Enders, A. Kelic-Heil, Rene Reifarth, Roman Gernhäuser, and Marina Petri

Subjects
Physics, Nuclear and High Energy Physics, Proton, Scattering, Eikonal equation, Nuclear Theory, chemistry.chemical_element, lcsh:QC1-999, Cross section (physics), chemistry, ddc:530, Atomic physics, Nuclear Experiment, Nucleon, Carbon, lcsh:Physics
Abstract

Physics letters / B B 797, 134802 (2019). doi:10.1016/j.physletb.2019.134802, Published by North-Holland Publ., Amsterdam

Published
2019

88. Field emission from three-dimensional epitaxial grown GaN-microrods

Author

Rupert Schreiner, Christoph Langer, R. Lawrowski, and Christian Prommesberger

Subjects
010302 applied physics, Materials science, business.industry, Gallium nitride, Heterojunction, 02 engineering and technology, Nitride, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Field electron emission, chemistry.chemical_compound, Semiconductor, chemistry, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, Quantum well, Diode
Abstract

A novel three-dimensional epitaxial technique allows on patterned substrates the realization of gallium nitride pillars, also known as nano- and microrods. The typical dimensions of the microrods are in the range of one micron for the radius of the hexagonal footprint and about 10 μm in height. The microrods consist of a semiconductor heterostructure with an n GaN core, a n-GaN shell, a p GaN shell and an intermediate quantum well layer. The field emission properties were investigated in diode configuration by integral field emission measurements in a vacuum chamber at pressures around 10−9 mbar. The spacer was mica with a thickness of 50 μm. A metallized fine-meshed nitride grid (or a metallized Si-grid) was used as anode. A current of about 1 μA at a voltage of 1250 V (1750 V) was measured. An onset field of about 12.5 MV/m (20 MV/m) and field enhancement factors in the range of 200 to 500 (150 to 300) were found. The investigation with the fine-meshed grid showed an expected pronounced saturation region.

Published
2016

89. Photo-enhanced field emission properties of p-doped black Si arrays

Author

Dirk Lützenkirchen-Hecht, Christian Prommesberger, Rupert Schreiner, Pavel Serbun, Christoph Langer, S. Mingels, G. Müller, and V. Porshyn

Subjects
010302 applied physics, Materials science, business.industry, Doping, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Field electron emission, Decay time, Photosensitivity, Saturation current, 0103 physical sciences, Optoelectronics, Laser illumination, 0210 nano-technology, business, Saturation (magnetic), Common emitter
Abstract

We have carried out systematic investigations of p-type black Si field emitter arrays under laser illumination. As expected the current-voltage characteristic revealed a strong saturation providing a high photosensitivity, which had a maximum on-off ratio of 43 at a maximum current of 13 μA. The saturation current was stable in the dark as well as under illumination with fluctuations

Published
2016

90. Field emission from black silicon structures with integrated gate electrode

Author

R. Lawrowski, Christian Prommesberger, Christoph Langer, and Rupert Schreiner

Subjects
010302 applied physics, Materials science, Fabrication, business.industry, Whiskers, Black silicon, Analytical chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, law.invention, Field electron emission, chemistry.chemical_compound, chemistry, law, Etching (microfabrication), 0103 physical sciences, Electrode, Optoelectronics, 0210 nano-technology, business, Common emitter
Abstract

Black silicon structures with integrated gate electrode were realized by using an improved fabrication process. An enhanced insulation layer was achieved by a combination of dry and wet oxidation, and a gold layer was evaporated as gate electrode. The black silicon structures were prepared with a RIE/ICP etching process at room temperature. Arrays of 16 and 100 apertures with buried p-doped black silicon whiskers have been fabricated. These structures have an emitter height of approximately 1.5 μm with tip radii between 5 nm and 30 nm. The whiskers are surrounded by the gate electrode in a distance of 1.5 μm. Integral field emission measurements yielded an onset voltage of 92 V for 16 apertures and 60 V for 100 apertures for an emission current of 1 nA. Maximum emission currents up to 0.2 μA were observed for the array with 100 apertures at a cathode voltage of 200 V. Stability measurements showed a current fluctuation of ± 21% at a mean value of the emission current of 12 nA over a period of 30 minutes for 16 apertures with b-Si whiskers.

Published
2016

91. Field emission behavior of Au-tip-coated p-type Si pillar structures

Author

Christian Prommesberger, Florian Dams, S. Mingels, Rupert Schreiner, Christoph Langer, Felix Düsberg, Martin R. Hofmann, Michael Bachmann, G. Müller, V. Porshyn, D. Lutzenkirchen-Heicht, Andreas Pahlke, Pavel Serbun, and R. Lawrowski

Subjects
010302 applied physics, Materials science, Silicon, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, law.invention, Field electron emission, Halogen lamp, chemistry, Saturation current, law, 0103 physical sciences, Reactive-ion etching, Thin film, 0210 nano-technology, Saturation (magnetic)
Abstract

Precisely aligned high-aspect-ratio (HAR) silicon tip arrays were fabricated using enhanced reactive ion etching with an inductively-coupled-plasma followed by a sharpening oxidation. A gold thin film was then sputtered only on the tips of the HAR structures. Field-emission (FE) properties from Au-coated HAR p-Si tip array cathodes have been systematically investigated by means of field emission scanning microscopy (FESM). A rather high efficiency of the HAR Si structures (71% at 550 V), but limited homogeneous FE with currents of 1–600 nA might be correlated with the varying geometry of the tips and the presence of oxides. I-V measurements of single Au-coated HAR emitters revealed activation effects and the saturation current region at 3 nA. An increase of the saturation current by 4 orders of magnitude was observed during 20 hours of conditioning at constant voltage, which finally resulted in nearly reproducible FN curves with a s-factor of 473. An excellent stability of the emission current of less than 1 % was obtained during the additional long-time conditioning at constant voltage. Optical switching under halogen lamp illumination resulted in at least 2 times higher saturation currents and showed a linear dependence of the FE current on the light color temperature.

Published
2016

92. Extraction of the characteristics of limiting elements from field emission measurement data

Author

Felix Düsberg, Rupert Schreiner, Christoph Langer, Michael Bachmann, R. Lawrowski, Florian Dams, Martin Hofmann, Christian Prommesberger, and Andreas Pahlke

Subjects
Materials science, Field emitter array, Analytical chemistry, Electrical element, Limiting, Computational physics, law.invention, Field electron emission, Computer Science::Emerging Technologies, law, Resistor, Saturation (magnetic), Voltage drop, Network analysis
Abstract

In this contribution we will present an algorithm to extract the characteristics of non-Fowler-Nordheim (FN) circuit elements from saturation limited field emission (FE) measurement data. The method for calculating the voltage drop on limiting circuit elements is based on circuit theory as well as Newton's method. Since no assumption on the limiting circuit is made, this method is applicable to any FE data showing saturation. To be able to determine the significance of any parameter output, the uncertainties of data and extracted parameters are fully taken into account throughout the algorithm. External serial resistors and a limiting p-doped substrate are analyzed, where the latter shows a diode-like behavior.

Published
2016

93. Gated p-Si field emission cathode applied in an ionization vacuum gauge

Author

Yifeng Huang, Christian Prommesberger, Rupert Schreiner, Christoph Langer, R. Lawrowski, and J.C. She

Subjects
010302 applied physics, Materials science, Analytical chemistry, Ion current, 02 engineering and technology, Vacuum arc, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, Ion source, law.invention, Anode, Field electron emission, law, Ionization, 0103 physical sciences, Hot-filament ionization gauge, Atomic physics, 0210 nano-technology
Abstract

A commercial Bayard-Alpert ionization vacuum gauge was equipped with a field emission electron source based on a cathode consisting of an array of 16 gated, p-doped, and DLC-coated Si-tips and characterized. An anode current of about 1.3 μA led to an ion current of 7 fA at 3×10−7 mbar and 0.8 pA at 4×10−5 mbar. Whereas at pressures higher than 4×10−5 mbar the emission current of the electron source decreased, the ratio of ion and anode current remained linear. A nearly constant sensitivity of ∼ 17 mbar−1 of the ionization vacuum gauge within the investigated pressure range was depicted.

Published
2016

94. Coulomb dissociation of $^{20,21}$N

Author

A. Estrade, G. Burgunder, Andreas Martin Heinz, Andreas Wagner, Enrique Casarejos, Roy Crawford Lemmon, C. Wimmer, Ethan Uberseder, M. Heine, T. Le Bleis, N. Kurz, H. O. U. Fynbo, Olof Tengblad, D. Cortina-Gil, V. Stoica, F. Farinon, L. Atar, D. Yakorev, Joachim Enders, Helmut Weick, Z. Elekes, Carlos A. Bertulani, J. Sanchez del Rio Saez, Håkan T Johansson, Daniel Bemmerer, M. Freudenberger, D. Galaviz, Mikhail V. Zhukov, Heiko Scheit, Herbert A. Simon, A. Ignatov, P. Diaz-Fernandez, Nasser Kalantar-Nayestanaki, C. Wheldon, Thomas Aumann, P. Velho, J. Van de Walle, K. Riisager, Pavel Golubev, U. Datta Pramanik, J. Taylor, J. Marganiec, G. L. Wilson, Ralf Plag, J. Benlliure, O. Lepyoshkina, Marielle Chartier, N. I. Ashwood, A. Movsesyan, M. Röder, Andreas Zilges, Yasuhiro Togano, P. J. Woods, Ronja Thies, S. Pietri, R. Kanungo, Kai Zuber, Najafi, M. Labiche, M. J. G. Borge, Thomas Nilsson, A. Prochazka, G. Ribeiro, Christoph Langer, Ángel Perea, Roman Gernhäuser, G. Ickert, T. Adachi, R. Crespo, K. Boretzky, J. S. Winfield, W. N. Catford, G. Rastrepina, H. Alvarez-Pol, Bo Jakobsson, M. Barr, L. M. Fraile, C. Nociforo, F. Wamers, Rahaman, M. V. Ricciardi, M. Mostazo Caro, Björn Jonson, T. Kröll, Y. Aksyutina, Vladimir Avdeichikov, R. Knöbel, Matthias Heil, C. Caesar, B. Streicher, Joakim Cederkäll, J. Hagdahl, J. Kurcewicz, Deniz Savran, M. Caamaño, V. Volkov, Satoru Terashima, M. Holl, O. Ershova, Kathrin Göbel, A. Henriques, Martin Freer, J. Alcantara, Jorge Machado, Marina Petri, D. M. Rossi, Tanja Heftrich, S. Chakraborty, Mario Weigand, Simon Lindberg, R. Krücken, D. Gonzalez Diaz, Catherine Rigollet, Hans Geissel, Rene Reifarth, O. Sorlin, L. V. Chulkov, I. Dillmann, Stefanos Paschalis, V. Panin, S. Altstadt, S. Beceiro, A. Kelic-Heil, Helmholtz zentrum für Schwerionenforschung GmbH (GSI), 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), 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
Physics, Light nucleus, 010308 nuclear & particles physics, Thermonuclear reaction, Aucun, FOS: Physical sciences, chemistry.chemical_element, Detailed balance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Dissociation (chemistry), Ion, chemistry, 0103 physical sciences, Coulomb, Fluorine, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Nuclear Experiment, Excitation
Abstract

International audience; Neutron-rich light nuclei and their reactions play an important role for the creation of chemical elements. Here, data from a Coulomb dissociation experiment on $^{20,21}$N are reported. Relativistic $^{20,21}$N ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the $^{19}\mathrm{N}(\mathrm{n},\gamma)^{20}\mathrm{N}$ and $^{20}\mathrm{N}(\mathrm{n},\gamma)^{21}\mathrm{N}$ excitation functions and thermonuclear reaction rates have been determined. The $^{19}\mathrm{N}(\mathrm{n},\gamma)^{20}\mathrm{N}$ rate is up to a factor of 5 higher at $T

Published
2016

95. Coulomb dissociation of P 27 at 500 MeV/u

Author

Enrique Casarejos, C. Muentz, D. Galaviz, Andreas Wagner, Z. Elekes, K. Mahata, A. Chatillon, C. Rodríguez Tajes, T. Le Bleis, D. Cortina-Gil, Yu. A. Litvinov, N. Kurz, Hans Geissel, Fairouz Hammache, Helmut Weick, W. Ott, K. Sümmerer, H. Simon, F. Wamers, S. Giron, M. Stanoiu, Michael Heil, H. Alvarez-Pol, W. Prokopowicz, Kristian Larsson, Thomas Aumann, C. Nociforo, Uwe Greife, S. Beceiro Novo, C. Wimmer, J. Marganiec, Christoph Langer, Håkan T Johansson, Stefan Typel, Joachim Stroth, Zsolt Fülöp, D. Rossi, K. Boretzky, Michael Wiescher, J. Hoffman, O. Kiselev, U. Datta-Pramanik, R. Plag, Stefanos Paschalis, European Money Markets Institute, Helmholtz Centre for Heavy Ion Research, Xunta de Galicia, Ministerio de Economía y Competitividad (España), Federal Ministry of Education and Research (Germany), National Science Foundation (US), Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements (US), Nuclear Astrophysics Virtual Institute (Germany), Helmholtz Association, European Commission, Universidad de Santiago de Compostela, Helmholtz International Center for FAIR, Institut de Physique Nucléaire d'Orsay (IPNO), 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), and R3B Collaboration

Subjects
Physics, 010308 nuclear & particles physics, S-factor, Monte Carlo method, Nuclear structure, Resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Dissociation (chemistry), Intruder state, Nuclear physics, 0103 physical sciences, Coulomb, Atomic physics, 010306 general physics, Nuclear Experiment, Excitation
Abstract

J. Marganiec et al. ; 15 págs.; 14 figs.; 6 tabs., The proton-capture reaction Si26(p,γ)P27 was studied via Coulomb dissociation (CD) of P27 at an incident energy of about 500 MeV/u. The three lowest-lying resonances in P27 have been populated and their resonance strengths have been measured. In addition, a nonresonant direct-capture component was clearly identified and its astrophysical S factor measured. The experimental results are compared to Monte Carlo simulations of the CD process using a semiclassical model. Our thermonuclear reaction rates show good agreement with the rates from a recent compilation. With respect to the nuclear structure of P27 we have found evidence for a negative-parity intruder state at 2.88-MeV excitation energy. ©2016 American Physical Society, This project was supported by BMBF, EU(EURONS), EMMI, GSI Darmstadt, FIAS, NAVI, GSI-TU Darmstadt cooperation, and HIC for FAIR. S.T. was supported by the Helmholtz Association (HGF) through the Nuclear Astrophysics Virtual Institute (VH-VI-417). C.L. acknowledges support from JINA-CEE under Grants No. PHY-1430152 and No. PHY-0822648 of the National Science Foundation. S.B.N. and the University of Santiago de Compostela group acknowledge support from the Spanish Ministerio de Educacion, under Grants No. FPU-AP2006-01474, No. FPA2012-39404-C02- 01, and No. FPA2013-47831-C2-1 and from Xunta de Galicia under Grant No. GRC2013-11.

Published
2016

96. Integral measurement of the 12C(n, p)12B reaction up to 10 GeV

Author

M. P. W. Chin, F. Roman, A. R. García, M. Brugger, G. Cortes, C. Eleftheriadis, Thomas Rauscher, D. Karadimos, D. Tarrío, A. Pavlik, E. González-Romero, T. Ware, A. Manousos, A. Ventura, F. Mingrone, E. Griesmayer, M. A. Cortés-Giraldo, M. Mastromarco, C. Lederer, Mario Weigand, C. Domingo-Pardo, J. Andrzejewski, Srinivasan Ganesan, S. Altstadt, G. Vannini, N. Colonna, J. Marganiec, Massimo Barbagallo, L. Cosentino, D. Bosnar, M. Mirea, F. Bečvář, I. F. Gonçalves, A. Riego, Anton Wallner, E. Mendoza, Peter Schillebeeckx, S. Valenta, F. Calviño, V. Bécares, H. Leeb, I. Duran, K. Fraval, Carlos Guerrero, Fabio Belloni, V. Variale, Marco Calviani, J. Perkowski, P. Vaz, S. Heinitz, M. Kokkoris, D. Cano-Ott, Rene Reifarth, M. Krtička, Stefan Schmidt, G. Tagliente, M. Diakaki, F. Gunsing, Vittorio Boccone, Christoph Langer, J. M. Quesada, L. Tassan-Got, Roberto Versaci, Cristian Massimi, T. Martinez, M.B. Gómez-Hornillos, D. G. Jenkins, A. K. Saxena, Arnaud Ferrari, Alberto Mengoni, J. Billowes, P. M. Milazzo, A. Musumarra, C. Carrapiço, E. Chiaveri, P. F. Mastinu, E. Jericha, Paolo Finocchiaro, Dorothea Schumann, C. Weiß, A. J. M. Plompen, W. Mondalaers, G. Giubrone, M. J. Vermeulen, Jeri Kroll, R. Sarmento, C. Paradela, L. Audouin, T. J. Wright, Petar Žugec, R. Vlastou, E. Berthoumieux, Roberto Losito, Rugard Dressler, A. Tsinganis, L.S. Leong, Vasilis Vlachoudis, F. Cerutti, Javier Praena, S. Lo Meo, P. Gurusamy, F. Käppeler, J. L. Tain, Niko Kivel, C. Rubbia, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, 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 de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, 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), Žugec, P, Colonna, N., Bosnar, D., Ventura, A., Mengoni, A., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Diakaki, M., Domingo-Pardo, C., Dressler, R., Duran, I., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A.R., Giubrone, G., Gómez-Hornillos, M.B., Gonçalves, I.F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D.G., Jericha, E., Käppeler, F., Karadimos, D., Kivel, N., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L.S., Lo Meo, S., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Mendoza, E., Milazzo, P.M., Mingrone, F., Mirea, M., Mondalaers, W., Musumarra, A., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J.L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Versaci, R., Vermeulen, M.J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear and High Energy Physics, 12C(n, p)12B reaction, integral measurement, n_TOF, Reaction, FOS: Physical sciences, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Time of flight technique, 7. Clean energy, 01 natural sciences, Nuclear physics, Cross section (physics), Neutron flux, 0103 physical sciences, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Large Hadron Collider, Cross section, 010308 nuclear & particles physics, Time of flight, 13. Climate action, Production (computer science), Beam (structure)
Abstract

The integral measurement of the $^{12}$C(n,p)$^{12}$B reaction was performed at the neutron time of flight facility n_TOF at CERN. The total number of $^{12}$B nuclei produced per neutron pulse of the n_TOF beam was determined using the activation technique in combination with a time of flight technique. The cross section is integrated over the n_TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the $^{235}$U(n,f) reaction, the neutron energy spectrum above 200 MeV has been reevaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the $^{12}$C(n,p)$^{12}$B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the $^{12}$B production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters., 14 pages, 11 figures, 3 tables

Published
2016

97. Time-of-flight mass measurements of neutron-rich chromium isotopes up toN=40and implications for the accreted neutron star crust

Author

Jack Winkelbauer, S. Ahn, Alfredo Estrade, Wolfgang Mittig, Sherry Towers, J. Stevens, Oleg B. Tarasov, Christoph Langer, Remco Zegers, Kamila Sieja, Dan Shapira, Fernando Montes, Karl Smith, Michael Famiano, H. Chung, David J. Morrissey, M. Scott, Richard H. Cyburt, Kathrin Wimmer, John Yurkon, Zach Meisel, Daniel Bazin, Wanpeng Tan, J. F. Carpino, J. Browne, Alexandra Gade, J. Pereira, Milan Matos, B. A. Brown, J. Schatz, Hendrik Schatz, and Sebastian George

Subjects
Physics, Valence (chemistry), Isotope, 010308 nuclear & particles physics, Island of inversion, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, Atomic mass, Nuclear physics, Neutron star, Chromium, Time of flight, chemistry, 13. Climate action, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We present the mass excesses of 59-64Cr, obtained from recent time-of-flight nuclear mass measurements at the National Superconducting Cyclotron Laboratory at Michigan State University. The mass of 64Cr is determined for the first time, with an atomic mass excess of -33.48(44) MeV. We find a significantly different two-neutron separation energy S2n trend for neutron-rich isotopes of chromium, removing the previously observed enhancement in binding at N=38. Additionally, we extend the S2n trend for chromium to N=40, revealing behavior consistent with the previously identified island of inversion in this region. We compare our results to state-of-the-art shell-model calculations performed with a modified Lenzi-Nowacki-Poves-Sieja interaction in the fp shell, including the g9/2 and d5/2 orbits for the neutron valence space. We employ our result for the mass of 64Cr in accreted neutron star crust network calculations and find a reduction in the strength and depth of electron-capture heating from the A=64 isobaric chain, resulting in a cooler than expected accreted neutron star crust. This reduced heating is found to be due to the >1-MeV reduction in binding for 64Cr with respect to values from commonly used global mass models.

Published
2016

98. Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN -€“ n_TOF

Author

S. Valenta, N. Colonna, Carlos Guerrero, M. P. W. Chin, P. Zugec, Marco Calviani, V. Ketlerov, F. Roman, C. Le Naour, Masayuki Igashira, V. Bécares, J. Salgado, N. Patronis, K. Fraval, E. Leal-Cidoncha, G. Cortes, C. Eleftheriadis, Roberto Capote, J. Pancin, L. Cosentino, W. Mondelaers, Thomas Rauscher, A. K. Saxena, Arnaud Ferrari, G. Rudolf, P. Rullhusen, Y. Kadi, J. Marganiec, D. Karadimos, S. Andriamonje, W.I. Furman, M. Embid-Segura, J. Billowes, D. Cano-Ott, C. Santos, S. Heinitz, M. Diakaki, B. Berthier, M. B. Gómez-Hornillos, E. González-Romero, E. Chiaveri, P. Cennini, Christoph Langer, F. Cerutti, M. Kerveno, L. Sarchiapone, Michael Heil, M. J. Vermeulen, L. Plukis, K. Fujii, G. Giubrone, M. Mosconi, A. R. García, M. Wiesher, I. F. Gonçalves, P. F. Mastinu, V. Variale, Roberto Versaci, W. Dridi, M. Brugger, T. Ware, F. Voss, S. O'Brien, E. Mendoza, E. Jericha, Paolo Finocchiaro, Dorothea Schumann, Diego Tarrio, Rene Reifarth, F. Kaeppeler, Stefan Schmidt, P. Pavlopoulos, Javier Praena, S. Lo Meo, E. Griesmayer, S. David, Srinivasan Ganesan, R. Terlizzi, P. Baumann, Vittorio Boccone, D. G. Jenkins, J. M. Quesada, Peter Schillebeeckx, L. Tassan-Got, A. Manousos, D. Bosnar, G. Tagliente, F. Mingrone, J. Andrzejewski, G. Aerts, P. Gurusamy, Ralf Plag, M. Kokkoris, Alberto Mengoni, M. Krtička, F. Calviño, M. A. Cortés-Giraldo, L. Ferrant, I. Duran, H. Álvarez, J. L. Tain, C. Weiß, V. Konovalov, C. Pretel, Niko Kivel, D. Villamarin, L. Perrot, T. Martinez, C. Rubbia, S. Marrone, S. Altstadt, P. Vaz, Alberto Ventura, P. M. Milazzo, Aaron Couture, C. Carrapiço, C. Lampoudis, A. Pavlik, C. Domingo-Pardo, G. Vannini, A. Musumarra, Marco T. Pigni, I. Dillmann, D. Karamanis, T. J. Wright, M. C. Vincente, Christoph A. Stephan, S. Isaev, R. C. Haight, C. Paradela, L. Audouin, R. Sarmento, R. Vlastou, E. Berthoumieux, M. Mastromarco, L. Tavora, Massimo Barbagallo, Anton Wallner, E. Dupont, A. J. M. Plompen, James L. Cox, Corrie S. Moreau, Jeri Kroll, C. Lederer, Maria Victoria Lozano, A. Riego, S. Walter, A. Goverdovski, F. Alvarez-Velarde, Gerald Badurek, Roberto Losito, F. Gramegna, F. Belloni, F. Gunsing, A. Poch, Cristian Massimi, Rugard Dressler, K. Wisshak, Mario Weigand, F. Becvar, M. Mirea, A. Tsinganis, H. Leeb, J. Perkowski, L.S. Leong, Vasilis Vlachoudis, Serot, O., Diakaki, M., Audouin, L., Berthoumieux, E., Calviani, M., Colonna, N., Dupont, E., Duran, I., Gunsing, F., Leal-Cidoncha, E., Le Naour, C., Leong, L.S., Mastromarco, M., Paradela, C., Tarrio, D., Tassan-Got, L., Aerts, G., Altstadt, S., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Badurek, G., Barbagallo, M., Baumann, P., Becares, V., Becvar, F., Belloni, F., Berthier, B., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calvino, F., Cano-Ott, D., Capote, R., Carrapiço, C., Cennini, P., Cerutti, F., Chiaveri, E., Chin, M., Cortes, G., Cortes-Giraldo, M.A., Cosentino, L., Couture, A., Cox, J., David, S., Dillmann, I., Domingo-Pardo, C., Dressler, R., Dridi, W., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Finocchiaro, P., Fraval, K., Fujii, K., Furman, W., Ganesan, S., Garcia, A.R., Giubrone, G., Gomez-Hornillos, M.B., Goncalves, I.F., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gurusamy, P., Haight, R., Heil, M., Heinitz, S., Igashira, M., Isaev, S., Jenkins, D.G., Jericha, E., Kadi, Y., Kaeppeler, F., Karadimos, D., Karamanis, D., Kerveno, M., Ketlerov, V., Kivel, N., Kokkoris, M., Konovalov, V., Krticka, M., Kroll, J., Lampoudis, C., Langer, C., Lederer, C., Leeb, H., Lo Meo, S., Losito, R., Lozano, M., Manousos, A., Marganiec, J., Martinez, T., Marrone, S., Massimi, C., Mastinu, P., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Moreau, C., Mosconi, M., Musumarra, A., O’Brien, S., Pancin, J., Patronis, N., Pavlik, A., Pavlopoulos, P., Perkowski, J., Perrot, L., Pigni, M.T., Plag, R., Plompen, A., Plukis, L., Poch, A., Pretel, C., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rudolf, G., Rubbia, C., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Stephan, C., Tagliente, G., Tain, J.L., Tavora, L., Terlizzi, R., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vermeulen, M.J., Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Wallner, A., Walter, S., Ware, T., Weigand, M., Weiß, C., Wiesher, M., Wisshak, K., Wright, T., Zugec, P., Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group

Subjects
Nuclear reaction, Fission, QC1-999, Nuclear Theory, Nuclear physics, Mechanical engineering, U238, neutron fission, 7. Clean energy, 01 natural sciences, Fissió nuclear, ANGULAR-DISTRIBUTION, Subatomär fysik, Cross section (physics), 0103 physical sciences, Subatomic Physics, Neutron, 010306 general physics, Nuclear Experiment, Energies::Energia nuclear [Àrees temàtiques de la UPC], Physics, Large Hadron Collider, 010308 nuclear & particles physics, Nuclear fission, Física nuclear
Abstract

The U-238 fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The U-238 fission cross section has been measured relative to the U-235 fission cross section at CERN - n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

Published
2016

99. The 236U neutron capture cross-section measured at the n TOF CERN facility

Author

A. J. M. Plompen, Rene Reifarth, Stefan Schmidt, J. M. Quesada, L. Tassan-Got, C. Lampoudis, M. P. W. Chin, C. Domingo-Pardo, M. Sabaté-Gilarte, M. B. Gómez-Hornillos, Tanja Heftrich, V. Ketlerov, Christoph Langer, F. Roman, A. Riego-Perez, M. S. Robles, G. Vannini, G. Tagliente, C. Paradela, Srinivasan Ganesan, R. Sarmento, F. Cerutti, A. R. García, P. Vaz, D. Cano-Ott, R. Vlastou, M. Mirea, L. Audouin, M. J. Vermeulen, M. Diakaki, Alberto Ventura, E. Berthoumieux, I. Duran, W. Mondelaers, G. Giubrone, C. Lederer, Mario Barbagallo, M. Brugger, M. Kokkoris, A. Pavlik, P. V. Sedyshev, D. G. Jenkins, A. Manousos, Jeri Kroll, A. Goverdovski, M. Licata, V. Variale, A. Tsinganis, M. Mastromarco, F. Käppeler, Roberto Versaci, Damir Bosnar, F. Mingrone, M. A. Cortés-Giraldo, Y. Kadi, J. Andrzejewski, K. Fraval, Petar Žugec, Nicola Colonna, J. Marganiec, E. Leal-Cidoncha, Anton Wallner, G. Cortes, Vasilis Vlachoudis, C. Carrapiço, C. Eleftheriadis, A. K. Saxena, C. Weiss, S. Valenta, D. Tarrío, J. L. Tain, L. S. Leong, Arnaud Ferrari, Javier Praena, T. Ware, Thomas Rauscher, Alberto Mengoni, Marco Calviani, E. Chiaveri, J. Billowes, P. F. Mastinu, E. Griesmayer, D. Karadimos, Roberto Losito, Jan Heyse, S. Heinitz, P. Koehler, M. Krtička, T. Martinez, Carlos Guerrero, V. Furman, T. J. Wright, Ariel Tarifeño-Saldivia, A. Hernández-Prieto, J. Lerendegui-Marco, I. F. Gonçalves, T. Katabuchi, Fabio Belloni, F. Calviño, H. Leeb, P. Gurusamy, J. Perkowski, E. González, Mario Weigand, C. Rubbia, F. Gunsing, Cristian Massimi, F. Bečvář, E. Mendoza, Peter Schillebeeckx, N. Dzysiuk, V. Bécares, V. Khryachkov, P. M. Milazzo, S. Altstadt, E. Jericha, Dorothea Schumann, J. A. Ryan, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, 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 de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, 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), Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Mastromarco, M., Barbagallo, M., Vermeulen, M.J., Colonna, N., Altstadt, S., Andrzejewski, J., Audouin, L., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Calviño, F., Calviani, M., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M.A., Diakaki, M., Domingo-Pardo, C., Durán, I., Dzysiuk, N., Eleftheriadis, C., Ferrari, A., Fraval, K., Furman, V., Gómez-Hornillos, M.B., Ganesan, S., García, A.R., Giubrone, G., Gonçalves, I.F., González, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Katabuchi, T., Ketlerov, V., Khryachkov, V., Koehler, P., Kokkoris, M., Kroll, J., Krtička, M., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L.S., Lerendegui-Marco, J., Licata, M., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A.J.M., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M., Roman, F., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiss, C., Wright, T., and Ž Ugec, P.

Subjects
Nuclear reaction, nTOF, QC1-999, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Physics and Astronomy (all), Cross section (physics), 0103 physical sciences, CERN, Neutron cross section, Nuclear Physics - Experiment, ddc:530, 010306 general physics, Absorption (electromagnetic radiation), Physics, Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Isotope, Cross section, Reaccions nuclears, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, Resonance, Calorimeter, 13. Climate action, Nuclear reactions
Abstract

International audience; The $^{236}$U isotope plays an important role in nuclear systems, both for future and currently operating ones. The actual knowledge of the capture reaction of this isotope is satisfactory in the thermal region, but it is considered insufficient for Fast Reactor and ADS applications. For this reason the $^{236} \text{U}(n, \gamma)$ reaction cross-section has been measured for the first time in the whole energy region from thermal energy up to 1 MeV at the n_TOF facility with two different detection systems: an array of C$_6$D$_6$ detectors, employing the total energy deposited method, and a 4$\pi$ total absorption calorimeter (TAC), made of 40 BaF$_2$ crystals. The two n_TOF data sets agree with each other within the statistical uncertainty in the Resolved Resonance Region up to 800 eV, while sizable differences (up to ≃ 20%) are found relative to the current evaluated data libraries. Moreover two new resonances have been found in the n_TOF data. In the Unresolved Resonance Region up to 200 keV, the n_TOF results show a reasonable agreement with previous measurements and evaluated data.

Published
2016
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100. Nuclear Data for the Thorium Fuel Cycle and the Transmutation of Nuclear Waste

Author

V. Variale, C. Paradela, M. A. Cortés-Giraldo, L. Audouin, A. Ventura, W. Mondalaers, Christoph Langer, M. Kokkoris, G. Giubrone, Jeri Kroll, A. R. García, Srinivasan Ganesan, T. J. Wright, G. Cortes, Alberto Mengoni, P. E. Koehler, Carlos Guerrero, F. Mingrone, J. Andrzejewski, C. Lampoudis, A. Pavlik, A. Riego, D. Tarrío, R. Sarmento, Roberto Losito, M. Brugger, M. Mastromarco, Rugard Dressler, A. Hernández-Prieto, K. Fraval, Y. Kadi, J. L. Tain, C. Domingo-Pardo, Mario Barbagallo, A. Tsinganis, R. Vlastou, T. Ware, E. Chiaveri, Niko Kivel, C. Carrapiço, Anton Wallner, Nicola Colonna, E. Berthoumieux, L.S. Leong, P. F. Mastinu, D. G. Jenkins, E. Leal-Cidoncha, C. Eleftheriadis, A. K. Saxena, E. Griesmayer, Arnaud Ferrari, Vasilis Vlachoudis, M. Sabaté-Gilarte, G. Tagliente, Thomas Rauscher, C. Rubbia, Rene Reifarth, Petar Žugec, A. J. M. Plompen, M. Krtička, Stefan Schmidt, J. Billowes, D. Karadimos, Vittorio Boccone, A. Mallick, I. F. Gonçalves, F. Calviño, C. Lederer, T. Martinez, G. Vannini, J. M. Quesada, L. Tassan-Got, I. Duran, M. J. Vermeulen, Javier Praena, E. González-Romero, Fabio Belloni, M. P. W. Chin, S. Valenta, Marco Calviani, F. Cerutti, P. Vaz, E. Jericha, D. Bosnar, Dorothea Schumann, C. Weiß, P. M. Milazzo, Mario Weigand, M. Mirea, H. Leeb, J. Perkowski, F. Gunsing, Cristian Massimi, F. Bečvář, E. Mendoza, Peter Schillebeeckx, S. Altstadt, V. Bécares, A. Manousos, J. Marganiec, M. S. Robles, D. Cano-Ott, M. Diakaki, and F. Käppeler

Subjects
Nuclear fuel cycle, Nuclear technology, Stellar nucleosynthesis, Nuclear transmutation, Chemistry, Nuclear engineering, Nuclear Theory, Radioactive waste, Nuclear data, Neutron, Nuclear Experiment, Thorium fuel cycle
Abstract

Neutron-induced reaction cross sections play an important role in a wide variety of research fields, ranging from stellar nucleosynthesis, the investigation of nuclear level density studies, to applications of nuclear technology, including the transmutation of nuclear waste, accelerator-driven systems, and nuclear fuel cycle investigations. Simulations of nuclear technology applications largely rely on evaluated nuclear data libraries. These libraries are based both on experimental data and theoretical models. An outline of experimental nuclear data activities at CERN’s neutron time-of-flight facility, n_TOF, will be presented.

Published
2016

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