Search

Your search keyword '"C. Massimi"' showing total 113 results
Start Over Author "C. Massimi"
113 results on '"C. Massimi"'

101. 197Au(n,γ) - towards a new standard for energies relevant to stellar nucleosynthesis

Author

N. Colonna, Ralf Nolte, C. Lederer, Matthias Heil, Ulrich Giesen, Rene Reifarth, Stefan Schmidt, I. Dillmann, Anton Wallner, M. Mosconi, Alberto Mengoni, C. Domingo-Pardo, F. Käppeler, F. Gunsing, Cristian Massimi, C Lederer, N Colonna, I Dillmann, C Domingo-Pardo, U Giesen, F Gunsing, M Heil, F Käppeler, C Massimi, A Mengoni, M Mosconi, R Nolte, R Reifarth, S Schmidt, and A Wallner

Subjects
Physics, 197Au, History, Large Hadron Collider, Resolution (electron density), Neutron spectra, Resonance (particle physics), Neutron cross section standard, Computer Science Applications, Education, Nuclear physics, Cross section (physics), Stellar nucleosynthesis, Neutron source, Neutron, Nuclear Experiment, s process
Abstract

Two experiments were performed to resolve a discrepancy of the 197Au(n, γ) cross section between the IAEA standard evaluation and the reference cross section for astrophysical experiments in the lower keV energy region. We measured the 197Au(n, γ) reaction by means of the time-of-flight technique with n-TOF at CERN and extracted the cross section in the unresolved resonance region between 5-400 keV with an overall uncertainty from 3.9-6.7% for a resolution of 20 bins per energy decade. Additionally, we remeasured the neutron spectrum of the 7Li(p, n) 7Be reaction with E p=1912 keV, which was used as a neutron source for determining the astrophysical reference cross section. The n-TOF data are already fully analyzed and published. The results are in good agreement with the ENDF standard evaluation, but uncertainties don't allow to draw definite conclusions. The analysis of the neutron spectrum of 7Li(p, n) 7Be is underway, preliminary results will be reported here.

Published
2012

102. Measurements of high-energy neutron-induced fission ofnatPb and209Bi

Author

H. Álvarez, J. L. Tain, D. Cano-Ott, P. E. Koehler, Marco T. Pigni, Rene Reifarth, P. Pavlopoulos, I. Dillmann, J. M. Quesada, Masayuki Igashira, M. Kerveno, Christoph A. Stephan, G. Cortes, S. Lukic, G. Aerts, D. Tarrío, Corrie S. Moreau, S. Isaev, U. Abbondanno, F. Gunsig, Ralf Plag, Roberto Capote, A. Plukis, P.A. Assimakopoulos, F. Alvarez-Velarde, Gerald Badurek, G. Vannini, G. Tagliente, A. Ventura, C. Eleftheriadis, A. Herrera-Martinez, N. Patronis, W.I. Furman, C. Rubbia, S. Walter, A. Lindote, Arnaud Ferrari, M. C. Vicente, Thomas Rauscher, A. J. M. Plompen, R. Vlastou, L. Perrot, J. Marganiec, Alberto Mengoni, C. A. Papachristodoulou, E. Berthoumieux, S. Andriamonje, I. Lopes, L. Sarchiapone, D. Karadimos, E. Chiaveri, P. F. Mastinu, I. Savvidis, James L. Cox, L. Tassan-Got, Carlos Guerrero, E. González-Romero, H. Leeb, Heinz Oberhummer, R. C. Haight, F. Becvar, C. Paradela, L. Audouin, M. Krtička, C. Le Naour, R. Ferreira-Marques, T. Martinez, D. Trubert, Michael Wiescher, F. Voss, Cristian Massimi, K. Wisshak, S. David, B. Berthier, Y. Kadi, Michael Heil, Marco Calviani, E. Kossionides, I. Duran, V. Chepel, M. Oshima, G. Rudolf, C. T. Papadopoulos, Javier Praena, L. Ferrant, J. Andrzejewski, V. Vlachoudis, F. Neves, P. M. Milazzo, P. Baumann, D. Villamarin, C. Pretel, E. Jericha, K. Fujii, C. Santos, M. Embid-Segura, Isabel S. Gonçalves, S. Marrone, Manuel Lozano, L. Tavora, P. Rullhusen, P. Cennini, M. Mosconi, S. O'Brien, Nicola Colonna, F. Gramegna, R. Terlizzi, F. Käppeler, J. Pancin, J. Salgado, A. Poch, M. Dahlfors, C. Carrapiço, P. Vaz, Aaron Couture, B. Haas, F. Calviño, W. Dridi, C. Lampoudis, A. Pavlik, C. Domingo-Pardo, D. Karamanis, D. Tarrío, L. Tassan-Got, L. Audouin, B. Berthier, I. Duran, L. Ferrant, S. Isaev, C. Le Naour, C. Paradela, C. Stephan, D. Trubert, U. Abbondanno, G. Aert, H. Álvarez, F. Álvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, G. Badurek, P. Baumann, F. Becvár, E. Berthoumieux, F. Calviño, M. Calviani, D. Cano-Ott, R. Capote, C. Carrapiço, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Corte, A. Couture, J. Cox, M. Dahlfor, S. David, I. Dillmann, C. Domingo-Pardo, W. Dridi, C. Eleftheriadi, M. Embid-Segura, A. Ferrari, R. Ferreira-Marque, K. Fujii, W. Furman, I. Gonçalve, E. González-Romero, F. Gramegna, C. Guerrero, F. Gunsig, B. Haa, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, E. Jericha, Y. Kadi, F. Käppeler, D. Karadimo, D. Karamani, M. Kerveno, P. Koehler, E. Kossionide, M. Krticka, C. Lampoudi, H. Leeb, A. Lindote, I. Lope, M. Lozano, S. Lukic, J. Marganiec, S. Marrone, T. Martínez, C. Massimi, P. Mastinu, A. Mengoni, P.M. Milazzo, C. Moreau, M. Mosconi, F. Neve, H. Oberhummer, S. O’Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulo, N. Patroni, A. Pavlik, P. Pavlopoulo, L. Perrot, M.T. Pigni, R. Plag, A. Plompen, A. Pluki, A. Poch, J. Praena, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, C. Santo, L. Sarchiapone, I. Savvidi, G. Tagliente, J.L. Tain, L. Tavora, R. Terlizzi, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M.C. Vicente, V. Vlachoudi, R. Vlastou, F. Vo, S. Walter, M. Wiescher, and K. Wisshak

Subjects
High energy, Engineering, Fission, business.industry, Physics, QC1-999, Nuclear engineering, Nuclear Theory, Creative commons, Engineering physics, neutron time-of-flight facility, Neutron, Nuclear Experiment, business, License
Abstract

he CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.

Published
2010

103. Neutron capture cross section measurements for 197Au from 3.5 to 84 keV at GELINA

Author

I. Sirakov, R. Wynants, E. Dupont, Stefan Kopecky, Cristian Massimi, C. Lampoudis, Peter Schillebeeckx, V.G. Pronyaev, B. Becker, Ralph Massarczyk, M. Moxon, C. Massimi, B. Becker, E. Dupont, S. Kopecky, C. Lampoudi, R. Massarczyk, M. Moxon, V. Pronyaev, P. Schillebeeckx, I. Sirakov, and R. Wynants

Subjects
Physics, 197Au, Nuclear and High Energy Physics, RADIATIVE NEUTRON CAPTURE, Scintillator, NEUTRON TIME OF FLIGHT, Neutron temperature, Neutron cross section standard, Nuclear physics, Cross section (physics), Neutron flux, Ionization chamber, Neutron cross section, S PROCESS, Neutron source, Nuclear cross section
Abstract

Cross section measurements have been performed at the time-of-flight facility GELINA to determine the average capture cross section for 197Au in the energy region between 3.5 keV and 84 keV. Prompt γ-rays, originating from neutron-induced capture events, were detected by two C6 D6 liquid scintillators. The sample was placed at about 13m distance from the neutron source. The total energy detection principle in combination with the pulse height weighting technique was applied. The energy dependence of the neutron flux was measured with a double Frisch-gridded ionization chamber based on the 10B(n,α) reaction. The data have been normalized to the well-isolated and saturated 197Au resonance at 4.9 eV. Special care was taken to reduce bias effects due to the weighting function, normalization, dead time and background corrections. The total uncertainty due to normalization, neutron flux and weighting function is 1.0%. An additional uncertainty of 0.5% results from the correction for self-shielding and multiple interaction events. Fluctuations due to resonance structures have been studied by complementary measurements at a 30m flight path station. The results reported in this work deviate systematically by more than 5% from the cross section that is recommended as a reference for astrophysical applications. They are about 2% lower compared to an evaluation of the 197Au(n, γ) cross section, which was based on a least squares fit of experimental data available in the literature prior to this work. The average capture cross section as a function of neutron energy has been parameterized in terms of average resonance parameters. Maxwellian average cross sections at different temperatures have been calculated.

Full Text
View/download PDF

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

Author

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

Abstract

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

Published
2024
Full Text
View/download PDF

105. Measurement of the ^{140}Ce(n,γ) Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe.

Author

Amaducci S, Colonna N, Cosentino L, Cristallo S, Finocchiaro P, Krtička M, Massimi C, Mastromarco M, Mazzone A, Maugeri EA, Mengoni A, Roederer IU, Straniero O, Valenta S, Vescovi D, Aberle O, Alcayne V, Andrzejewski J, Audouin L, Babiano-Suarez V, Bacak M, Barbagallo M, Bennett S, Berthoumieux E, Billowes J, Bosnar D, Brown A, Busso M, Caamaño M, Caballero-Ontanaya L, Calviño F, Calviani M, Cano-Ott D, Casanovas A, Cerutti F, Chiaveri E, Cortés G, Cortés-Giraldo MA, Damone LA, Davies PJ, Diakaki M, Dietz M, Domingo-Pardo C, Dressler R, Ducasse Q, Dupont E, Durán I, Eleme Z, Fernández-Domínguez B, Ferrari A, Furman V, Göbel K, Garg R, Gawlik-Ramięga A, Gilardoni S, Gonçalves IF, González-Romero E, Guerrero C, Gunsing F, Harada H, Heinitz S, Heyse J, Jenkins DG, Junghans A, Käppeler F, Kadi Y, Kimura A, Knapová I, Kokkoris M, Kopatch Y, Kurtulgil D, Ladarescu I, Lederer-Woods C, Leeb H, Lerendegui-Marco J, Lonsdale SJ, Macina D, Manna A, Martínez T, Masi A, Mastinu P, Mendoza E, Michalopoulou V, Milazzo PM, Mingrone F, Moreno-Soto J, Musumarra A, Negret A, Nolte R, Ogállar F, Oprea A, Patronis N, Pavlik A, Perkowski J, Petrone C, Piersanti L, Pirovano E, Porras I, Praena J, Quesada JM, Ramos-Doval D, Rauscher T, Reifarth R, Rochman D, Rubbia C, Sabaté-Gilarte M, Saxena A, Schillebeeckx P, Schumann D, Sekhar A, Smith AG, Sosnin NV, Sprung P, Stamatopoulos A, Tagliente G, Tain JL, Tarifeño-Saldivia A, Tassan-Got L, Thomas T, Torres-Sánchez P, Tsinganis A, Ulrich J, Urlass S, Vannini G, Variale V, Vaz P, Ventura A, Vlachoudis V, Vlastou R, Wallner A, Woods PJ, Wright T, and Žugec P

Abstract

^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.

Published
2024
Full Text
View/download PDF

106. 74 Ge( n , γ ) cross section below 70 keV measured at n_TOF CERN.

Author

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

Abstract

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

Published
2022
Full Text
View/download PDF

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

Author

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

Abstract

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

Published
2020
Full Text
View/download PDF

108. ^{7}Be(n,p)^{7}Li Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN.

Author

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

Abstract

We report on the measurement of the ^{7}Be(n,p)^{7}Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a ^{7}Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal ^{7}Li(p,n)^{7}Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+^{7}Li reaction is also discussed.

Published
2018
Full Text
View/download PDF

109. ^{7}Be(n,α)^{4}He Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN.

Author

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

Abstract

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

Published
2016
Full Text
View/download PDF

110. Neutron capture cross section of unstable 63Ni: implications for stellar nucleosynthesis.

Author

Lederer C, Massimi C, Altstadt S, Andrzejewski J, Audouin L, Barbagallo M, Bécares V, Bečvář F, Belloni F, Berthoumieux E, Billowes J, Boccone V, Bosnar D, Brugger M, Calviani M, Calviño F, Cano-Ott D, Carrapiço C, Cerutti F, Chiaveri E, Chin M, Colonna N, Cortés G, Cortés-Giraldo MA, Diakaki M, Domingo-Pardo C, Duran I, Dressler R, Dzysiuk N, Eleftheriadis C, Ferrari A, Fraval K, Ganesan S, García AR, Giubrone G, Gómez-Hornillos MB, Gonçalves IF, González-Romero E, Griesmayer E, Guerrero C, Gunsing F, Gurusamy P, Jenkins DG, Jericha E, Kadi Y, Käppeler F, Karadimos D, Kivel N, Koehler P, Kokkoris M, Korschinek G, Krtička M, Kroll J, Langer C, Leeb H, Leong LS, Losito R, Manousos A, Marganiec J, Martínez T, Mastinu PF, Mastromarco M, Meaze M, Mendoza E, Mengoni A, Milazzo PM, Mingrone F, Mirea M, Mondelaers W, Paradela C, Pavlik A, Perkowski J, Pignatari M, Plompen A, Praena J, Quesada JM, Rauscher T, Reifarth R, Riego A, Roman F, Rubbia C, Sarmento R, Schillebeeckx P, Schmidt S, Schumann D, Tagliente G, Tain JL, Tarrío D, Tassan-Got L, Tsinganis A, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Versaci R, Vermeulen MJ, Vlachoudis V, Vlastou R, Wallner A, Ware T, Weigand M, Weiß C, Wright TJ, and Zugec P

Abstract

The 63Ni(n,γ) cross section has been measured for the first time at the neutron time-of-flight facility n_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian averaged cross sections were calculated for thermal energies from   kT=5-100  keV with uncertainties around 20%. Stellar model calculations for a 25M⊙ star show that the new data have a significant effect on the s-process production of 63Cu, 64Ni, and 64Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

Published
2013
Full Text
View/download PDF

111. Neutron cross-sections for next generation reactors: new data from n_TOF.

Author

Colonna N, Abbondanno U, Aerts G, Alvarez H, Alvarez-Velarde F, Andriamonje S, Andrzejewski J, Assimakopoulos P, Audouin L, Badurek G, Baumann P, Becvar F, Berthoumieux E, Calviani M, Calviño F, Cano-Ott D, Capote R, de Albornoz AC, Cennini P, Chepel V, Chiaveri E, Cortes G, Couture A, Cox J, Dahlfors M, David S, Dillman I, Dolfini R, Domingo-Pardo C, Dridi W, Duran I, Eleftheriadis C, Ferrant L, Ferrari A, Ferreira-Marques R, Frais-Koelbl H, Fujii K, Furman W, Goncalves I, González-Romero E, Goverdovski A, Gramegna F, Griesmayer E, Guerrero C, Gunsing F, Haas B, Haight R, Heil M, Herrera-Martinez A, Igashira M, Isaev S, Jericha E, Käppeler F, Kadi Y, Karadimos D, Karamanis D, Kerveno M, Ketlerov V, Koehler P, Konovalov V, Kossionides E, Krticka M, Lampoudis C, Leeb H, Lindote A, Lopes I, Lozano M, Lukic S, Marganiec J, Marques L, Marrone S, Martínez T, Massimi C, Mastinu P, Mengoni A, Milazzo PM, Moreau C, Mosconi M, Neves F, Oberhummer H, O'Brien S, Oshima M, Pancin J, Papachristodoulou C, Papadopoulos C, Paradela C, Patronis N, Pavlik A, Pavlopoulos P, Perrot L, Pigni MT, Plag R, Plompen A, Plukis A, Poch A, Pretel C, Quesada J, Rauscher T, Reifarth R, Rosetti M, Rubbia C, Rudolf G, Rullhusen P, Salgado J, Sarchiapone L, Savvidis I, Stephan C, Tagliente G, Tain JL, Tassan-Got L, Tavora L, Terlizzi R, Vannini G, Vaz P, Ventura A, Villamarin D, Vicente MC, Vlachoudis V, Vlastou R, Voss F, Walter S, Wendler H, Wiescher M, and Wisshak K

Subjects
Equipment Design, Equipment Failure Analysis, Neutrons, Reproducibility of Results, Sensitivity and Specificity, Neutron Capture Therapy instrumentation, Neutron Capture Therapy methods, Nuclear Reactors
Abstract

In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Published
2010
Full Text
View/download PDF

112. Functional toxicity and tolerance patterns of bioavailable Pd(II), Pt(II), and Rh(III) on suspended Saccharomyces cerevisiae cells assayed in tandem by a respirometric biosensor.

Author

Frazzoli C, Dragone R, Mantovani A, Massimi C, and Campanella L

Subjects
Biological Availability, Dose-Response Relationship, Drug, Drug Tolerance, Oxygen Consumption drug effects, Saccharomyces cerevisiae metabolism, Biosensing Techniques methods, Oxygen Consumption physiology, Palladium toxicity, Platinum toxicity, Rhodium toxicity, Saccharomyces cerevisiae drug effects
Abstract

Toxicological implications of exposure to bioavailable platinum group metals, here Pd, Pt, and Rh, are still to be clarified. This study obtained by a biosensor-based method preliminary information on potential effects on cellular metabolism as well as on possible tolerance mechanisms. Aerobic respiration was taken as the toxicological end point to perform tandem tests, namely functional toxicity test and tolerance test. Cells were suspended in the absence of essential constituents for growth. The dose-response curves obtained by exposure (2 h) to the metals (nanogram per gram range) suggested the same mechanisms of action, with Rh showing the greatest curve steepness and the lowest EC50 value. Conservative (95% lower confidence interval) EC10 values were 187, 85 and 51 ng g(-1) for Pt, Pd, and Rh respectively. Tolerance patterns were tested during the same runs. The full tolerance obtained after 12 h of exposure to each metal suggested mitochondrial inhibition of aerobic respiration as a target effect. The hazard rating of the metals in the tolerance test changed in the Rh EC50 range, where Rh showed the lowest toxicity. The observed tolerance might suggest a protective mechanism such as metallothionein induction at concentrations around the EC50 values. The performance of the bioassay was satisfactory, in terms of the limit of detection, repeatability, reproducibility, roboustness, sensibility, and stability; the method's critical uncertainty sources were identified for improvements.

Published
2007
Full Text
View/download PDF

113. [Epicardial lipoma. Report of a surgical case and review of the literature].

Author

Iacobone G, Bianchini F, Bucari S, Di Loreto C, Massimi C, Molini E, Noera G, and Palminiello A

Subjects
Electrocardiography, Heart Neoplasms surgery, Humans, Intracranial Embolism and Thrombosis etiology, Lipoma surgery, Male, Middle Aged, Myocardial Infarction etiology, Postoperative Complications, Heart Neoplasms diagnosis, Lipoma diagnosis
Abstract

A case of massive epicardial lipoma in an asymptomatic patient is presented. The diagnosis of solid intrapericardial mass was achieved by two-dimensional echocardiography without cardiac catheterization. The complications of postoperative course, which included myocardial infarction, cerebral embolism, and the patient's late sudden death, suggest that the cardiopulmonary bypass should be used in similar circumstances. Lipomas of the heart should be kept in mind in patients with unexplained enlargement of the cardiac silhouette whenever pericardial effusion and heart disease may be excluded.

Published
1982

Catalog

Books, media, physical & digital resources
See catalog results