840 results on '"Imbriani, G"'
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152. Recoil separator ERNA: acceptances in angle and energy
- Author
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Rogalla, D., Schürmann, D., Strieder, F., Aliotta, M., DeCesare, N., DiLeva, A., Lubritto, C., D’Onofrio, A., Gialanella, L., Imbriani, G., Kluge, J., Ordine, A., Roca, V., Röcken, H., Rolfs, C., Romano, M., Schümann, F., Terrasi, F., and Trautvetter, H.P.
- Published
- 2003
- Full Text
- View/download PDF
153. The LUNA II [formula omitted] accelerator
- Author
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Formicola, A., Imbriani, G., Junker, M., Bemmerer, D., Bonetti, R., Broggini, C., Casella, C., Corvisiero, P., Costantini, H., Gervino, G., Gustavino, C., Lemut, A., Prati, P., Roca, V., Rolfs, C., Romano, M., Schürmann, D., Strieder, F., Terrasi, F., Trautvetter, H.-P., and Zavatarelli, S.
- Published
- 2003
- Full Text
- View/download PDF
154. Improved astrophysical rate for the O(p, ) N reaction by underground measurements
- Author
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Bruno, C.G., Aliotta, M., Descouvemont, P., Best, A., Davinson, T., Bemmerer, D., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G.F., Corvisiero, P., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Zs., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, Gy., Imbriani, G., Junker, M., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F.R., Piatti, D., Prati, P., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M.P., and Trezzi, D.
- Abstract
The $^{18}$O(p,α)$^{15}$N reaction affects the synthesis of $^{15}$N, $^{18}$O and $^{19}$F isotopes, whose abundances can be used to probe the nucleosynthesis and mixing processes occurring deep inside asymptotic giant branch (AGB) stars. We performed a low-background direct measurement of the $^{18}$O(p,α)$^{15}$N reaction cross-section at the Laboratory for Underground Nuclear Astrophysics (LUNA) from center of mass energy Ec.m.=340 keV down to Ec.m.=55 keV, the lowest energy measured to date corresponding to a cross-section of less than 1 picobarn/sr. The strength of a key resonance at center of mass energy Er=90 keV was found to be a factor of 10 higher than previously reported. A multi-channel R-matrix analysis of our and other data available in the literature was performed. Over a wide temperature range, T=0.01–1.00 GK, our new astrophysical rate is both more accurate and precise than recent evaluations. Stronger constraints can now be placed on the physical processes controlling nucleosynthesis in AGB stars with interesting consequences on the abundance of $^{18}$O in these stars and in stardust grains, specifically on the production sites of oxygen-rich Group II grains.
- Published
- 2019
155. A new approach to monitor $$^{13}\hbox {C}$$-targets degradation in situ for $$^{13}\hbox {C}(\alpha ,\hbox {n})^{16}\hbox {O}$$ cross-section measurements at LUNA
- Author
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Ciani, G. F., primary, Csedreki, L., additional, Balibrea-Correa, J., additional, Best, A., additional, Aliotta, M., additional, Barile, F., additional, Bemmerer, D., additional, Boeltzig, A., additional, Broggini, C., additional, Bruno, C. G., additional, Caciolli, A., additional, Cavanna, F., additional, Chillery, T., additional, Colombetti, P., additional, Corvisiero, P., additional, Davinson, T., additional, Depalo, R., additional, Di Leva, A., additional, Di Paolo, L., additional, Elekes, Z., additional, Ferraro, F., additional, Fiore, E. M., additional, Formicola, A., additional, Fülöp, Zs., additional, Gervino, G., additional, Guglielmetti, A., additional, Gustavino, C., additional, Gyürky, Gy., additional, Imbriani, G., additional, Junker, M., additional, Kochanek, I., additional, Lugaro, M., additional, Marigo, P., additional, Masha, E., additional, Menegazzo, R., additional, Mossa, V., additional, Pantaleo, F. R., additional, Paticchio, V., additional, Perrino, R., additional, Piatti, D., additional, Prati, P., additional, Schiavulli, L., additional, Stöckel, K., additional, Straniero, O., additional, Szücs, T., additional, Takács, M. P., additional, Terrasi, F., additional, Trezzi, D., additional, and Zavatarelli, S., additional
- Published
- 2020
- Full Text
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156. Assessing Risk Factors for the Increased Risk of Pulmunary Cancer in Salento Area (Southern Apulia)
- Author
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Castorini F, Melcarne A, Quarta F, De Filippis G, Raho A, Piscitelli P, Imbriani G, Rizzo E, Minichilli F, and Bianchi F
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Global and Planetary Change ,Increased risk ,Epidemiology ,business.industry ,Health, Toxicology and Mutagenesis ,Environmental health ,Public Health, Environmental and Occupational Health ,Case-control study ,Medicine ,Cancer ,business ,medicine.disease ,Pollution - Published
- 2019
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157. Cross section of the reaction 18O(p,γ)19F at astrophysical energies: The 90 keV resonance and the direct capture component
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Best, A., primary, Pantaleo, F.R., additional, Boeltzig, A., additional, Imbriani, G., additional, Aliotta, M., additional, Balibrea-Correa, J., additional, Bemmerer, D., additional, Broggini, C., additional, Bruno, C.G., additional, Buompane, R., additional, Caciolli, A., additional, Cavanna, F., additional, Chillery, T., additional, Ciani, G.F., additional, Corvisiero, P., additional, Csedreki, L., additional, Davinson, T., additional, deBoer, R.J., additional, Depalo, R., additional, Di Leva, A., additional, Elekes, Z., additional, Ferraro, F., additional, Fiore, E.M., additional, Formicola, A., additional, Fülöp, Zs., additional, Gervino, G., additional, Guglielmetti, A., additional, Gustavino, C., additional, Gyürky, Gy., additional, Junker, M., additional, Kochanek, I., additional, Lugaro, M., additional, Marigo, P., additional, Menegazzo, R., additional, Mossa, V., additional, Paticchio, V., additional, Perrino, R., additional, Piatti, D., additional, Prati, P., additional, Schiavulli, L., additional, Stöckel, K., additional, Straniero, O., additional, Strieder, F., additional, Szücs, T., additional, Takács, M.P., additional, Trezzi, D., additional, Wiescher, M., additional, and Zavatarelli, S., additional
- Published
- 2019
- Full Text
- View/download PDF
158. Direct measurements of low-energy resonance strengths of the 23Na(p,γ)24Mg reaction for astrophysics
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Boeltzig, A., primary, Best, A., additional, Pantaleo, F.R., additional, Imbriani, G., additional, Junker, M., additional, Aliotta, M., additional, Balibrea-Correa, J., additional, Bemmerer, D., additional, Broggini, C., additional, Bruno, C.G., additional, Buompane, R., additional, Caciolli, A., additional, Cavanna, F., additional, Chillery, T., additional, Ciani, G.F., additional, Corvisiero, P., additional, Csedreki, L., additional, Davinson, T., additional, deBoer, R.J., additional, Depalo, R., additional, Di Leva, A., additional, Elekes, Z., additional, Ferraro, F., additional, Fiore, E.M., additional, Formicola, A., additional, Fülöp, Zs., additional, Gervino, G., additional, Guglielmetti, A., additional, Gustavino, C., additional, Gyürky, Gy., additional, Kochanek, I., additional, Lugaro, M., additional, Marigo, P., additional, Menegazzo, R., additional, Mossa, V., additional, Munnik, F., additional, Paticchio, V., additional, Perrino, R., additional, Piatti, D., additional, Prati, P., additional, Schiavulli, L., additional, Stöckel, K., additional, Straniero, O., additional, Strieder, F., additional, Szücs, T., additional, Takács, M.P., additional, Trezzi, D., additional, Wiescher, M., additional, and Zavatarelli, S., additional
- Published
- 2019
- Full Text
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159. Present knowledgement of 3He(3He,2p)4He and 3He(4He,γ)7Be
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Imbriani, G., primary and deBoer, R. J., additional
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- 2019
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160. A new setup for the underground study of capture reactions
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Casella, C, Costantini, H, Lemut, A, Limata, B, Bemmerer, D, Bonetti, R, Broggini, C, Campajola, L, Cocconi, P, Corvisiero, P, Cruz, J, D’Onofrio, A, Formicola, A, Fülöp, Z, Gervino, G, Gialanella, L, Guglielmetti, A, Gustavino, C, Gyurky, G, Loiano, A, Imbriani, G, Jesus, A.P, Junker, M, Musico, P, Ordine, A, Parodi, F, Parolin, M, Pinto, J.V, Prati, P, Ribeiro, J.P, Roca, V, Rogalla, D, Rolfs, C, Romano, M, Rossi-Alvarez, C, Rottura, A, Schuemann, F, Somorjai, E, Strieder, F, Terrasi, F, Trautvetter, H.P, Vomiero, A, and Zavatarelli, S
- Published
- 2002
- Full Text
- View/download PDF
161. Off-line production of a 7Be radioactive ion beam
- Author
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Gialanella, L, Greife, U, De Cesare, N, D’Onofrio, A, Romano, M, Campajola, L, Formicola, A, Fulop, Z, Gyurky, G, Imbriani, G, Lubritto, C, Ordine, A, Roca, V, Rogalla, D, Rolfs, C, Russo, M, Sabbarese, C, Somorjai, E, Strieder, F, Terrasi, F, and Trautvetter, H.P
- Published
- 2002
- Full Text
- View/download PDF
162. Measurement of 1323 and 1487 keV resonances in N 15 (α,γ) F 19 with the recoil separator ERNA
- Author
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Di Leva, A., Imbriani, G., Buompane, R., Gialanella, L., Best, A., Cristallo, S., De Cesare, M., D'Onofrio, A., Duarte, J. G., Gasques, L. R., Morales-Gallegos, L., Pezzella, A., Porzio, G., Rapagnani, D., Roca, V., Romoli, M., Schürmann, D., Straniero, O., Terrasi, F., Di Leva, A., Imbriani, G., Buompane, R., Gialanella, L., Best, A., Cristallo, S., De Cesare, M., D'Onofrio, A., Duarte, J. G., Gasques, L. R., Morales-Gallegos, L., Pezzella, A., Porzio, G., Rapagnani, D., Roca, V., Romoli, M., Schã¼rmann, D., Straniero, O., and Terrasi, F.
- Subjects
Nuclear and High Energy Physics - Abstract
Background: The origin of fluorine is a widely debated issue. Nevertheless, the N15(α,γ)F19 reaction is a common feature among the various production channels so far proposed. Its reaction rate at relevant temperatures is determined by a number of narrow resonances together with the direct capture and the tails of the two broad resonances at Ec.m.=1323 and 1487 keV. Purpose: The broad resonances widths, Îγ and Îα, have to be measured with adequate precision in order to better determine their contribution to the N15(α,γ)F19 stellar reaction rate. Methods: Measurement through the direct detection of the F19 recoil ions with the European Recoil separator for Nuclear Astrophysics (ERNA) were performed. The reaction was initiated by a N15 beam impinging onto a He4 windowless gas target. The observed yield of the resonances at Ec.m.=1323 and 1487 keV is used to determine their widths in the α and γ channels. Results: We show that a direct measurement of the cross section of the N15(α,γ)F19 reaction can be successfully obtained with the recoil separator ERNA, and the widths Îγ and Îα of the two broad resonances have been determined. While a fair agreement is found with earlier determination of the widths of the 1487 keV resonance, a significant difference is found for the 1323 keV resonance Îα. Conclusions: The revision of the widths of the two more relevant broad resonances in the N15(α,γ)F19 reaction presented in this work is the first step toward a more firm determination of the reaction rate. At present, the residual uncertainty at the temperatures of the F19 stellar nucleosynthesis is dominated by the uncertainties affecting the direct capture component and the 364 keV narrow resonance, both so far investigated only through indirect experiments.
- Published
- 2017
163. This title is unavailable for guests, please login to see more information.
- Author
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Boeltzig, A., Best, A., Pantaleo, F. R., Imbriani, G., Junker, M., Aliotta, M., Balibrea-Correa, J., (0000-0003-0470-8367) Bemmerer, D., Broggini, C., Bruno, C. G., Buompane, R., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Deboer, R. J., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., (0000-0003-2506-6869) Munnik, F., Paticchio, V., Perrino, R., Piatti, D., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Strieder, F., (0000-0002-9980-4847) Szücs, T., Takács, M. P., Trezzi, D., Wiescher, M., Zavatarelli, S., Boeltzig, A., Best, A., Pantaleo, F. R., Imbriani, G., Junker, M., Aliotta, M., Balibrea-Correa, J., (0000-0003-0470-8367) Bemmerer, D., Broggini, C., Bruno, C. G., Buompane, R., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Deboer, R. J., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., (0000-0003-2506-6869) Munnik, F., Paticchio, V., Perrino, R., Piatti, D., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Strieder, F., (0000-0002-9980-4847) Szücs, T., Takács, M. P., Trezzi, D., Wiescher, M., and Zavatarelli, S.
- Published
- 2019
164. This title is unavailable for guests, please login to see more information.
- Author
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Best, A., Pantaleo, F. R., Boeltzig, A., Imbriani, G., Aliotta, M., Balibrea-Correa, J., Bemmerer, D., Broggini, C., Bruno, C. G., Buompane, R., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Deboer, R. J., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Paticchio, V., Perrino, R., Piatti, D., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Wiescher, M., Zavatarelli, S., Best, A., Pantaleo, F. R., Boeltzig, A., Imbriani, G., Aliotta, M., Balibrea-Correa, J., Bemmerer, D., Broggini, C., Bruno, C. G., Buompane, R., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Deboer, R. J., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Paticchio, V., Perrino, R., Piatti, D., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Wiescher, M., and Zavatarelli, S.
- Published
- 2019
165. This title is unavailable for guests, please login to see more information.
- Author
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Bruno, C. G., Aliotta, M., Descouvemont, P., Best, A., Davinson, T., Bemmerer, D., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Bruno, C. G., Aliotta, M., Descouvemont, P., Best, A., Davinson, T., Bemmerer, D., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Published
- 2019
166. Direct Capture Cross Section and the Ep = 71 and 105 keV Resonances in the 22Ne(p,γ)23Na Reaction
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Karakas, A., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Subjects
underground physics ,nuclear astrophysics, neon-sodium cycle, resonant reactions, stellar rates, underground physics ,nuclear astrophysics ,stellar rates ,neon-sodium cycle ,resonant reactions - Published
- 2018
167. A high-efficiency gas target setup for underground experiments, and redetermination of the branching ratio of the 189.5 KeV²²Ne(p,γ)²³Na resonance
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D’Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Zs., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, Gy., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Published
- 2018
168. Improved background suppression for radiative capture reactions at LUNA with HPGe and BGO detectors
- Author
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Boeltzig, A., Best, A., Imbriani, G., Junker, M., Aliotta, M., Bemmerer, D., Broggini, C., Bruno, C. G., Buompane, R., Cavanna, A. C. F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Deboer, R. J., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Kochanek, I., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Piatti, D., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Wiescher, M., and Zavatarelli, S.
- Abstract
Direct measurements of small nuclear reaction cross sections require a low background in the signal region of interest to achieve the necessary sensitivity. We describe two complementary detector setups that have been used for studies of reactions with solid targets at the Laboratory for Underground Nuclear Astrophysics (LUNA): a high-purity germanium detector and a bismuth germanate (BGO) detector. We present the effect of a customised lead shielding on the measured background spectra in the two detector setups at LUNA. We developed a model to describe the contributions of environmental and intrinsic backgrounds in the BGO detector measurements. Furthermore we present an upgrade of the data acquisition system for our BGO detector, which allows us to exploit the features of the segmented detector and overcome some of the limitations encountered in previous experiments. We conclude with a discussion on the improved sensitivity of the presented setups, and the benefits for ongoing and possible future measurements.
- Published
- 2018
169. Erratum: Three new low-energy resonances in the Ne 22 (p,γ) Na 23 reaction (Physical Review Letters (2015) 115 (252501) DOI: 10.1103/PhysRevLett.115.252501)
- Author
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Cavanna, F., Depalo, R., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Zs., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, Gy., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Scott, D. A., Somorjai, E., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Subjects
Physics and Astronomy (all) - Published
- 2018
170. A high-efficiency gas target setup for underground experiments, and redetermination of the branching ratio of the 189.5 keV 22Ne(p,γ)23Na resonance
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D'Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Subjects
Physics::Instrumentation and Detectors ,Nuclear Experiment - Abstract
The experimental study of nuclear reactions of astrophysical interest is greatly facilitated by a low-background, high-luminosity setup. The Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator offers ultra-low cosmic-ray induced background due to its location deep underground in the Gran Sasso National Laboratory (INFN-LNGS), Italy, and high intensity, 250-500 μA, proton and α ion beams. In order to fully exploit these features, a high-purity, recirculating gas target system for isotopically enriched gases is coupled to a high-efficiency, six-fold optically segmented bismuth germanate (BGO) γ-ray detector. The beam intensity is measured with a beam calorimeter with constant temperature gradient. Pressure and temperature measurements have been carried out at several positions along the beam path, and the resultant gas density profile has been determined. Calibrated γ-intensity standards and the well-known Ep = 278 keV 14N(p,γ)15O resonance were used to determine the γ-ray detection efficiency and to validate the simulation of the target and detector setup. As an example, the recently measured resonance at Ep = 189.5 keV in the 22Ne(p,γ)23Na reaction has been investigated with high statistics, and the γ-decay branching ratios of the resonance have been determined.
- Published
- 2018
171. Erratum: Three new low-energy resonances in the 22Ne(p,γ)23Na reaction
- Author
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Cavanna, F., Depalo, R., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Böltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Scott, D. A., Somorjai, E., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Abstract
Reported strengths of newly discovered resonances in [F. Cavanna et al., Phys. Rev. Lett. 115, 252501 (2015)] were affected by an error in the analysis. The energy straggling of the ion beam was erroneously neglected. When taking this effect into account, 18-19% higher values are found for the resonance strengths. The astrophysical implications are unchanged.
- Published
- 2018
172. Direct Capture Cross Section and the Ep=71 and 105 keV Resonances in the 22Ne(p,γ)23Na Reaction
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Dileva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Subjects
Hot Bottom Burning ,LUNA Laboratory Underground for Nuclear Astrophysics ,asymptotic giant branch stars ,nuclear astrophysics ,Radiative Capture - Abstract
The 22Ne(p,γ)23Na reaction, part of the neon-sodium cycle of hydrogen burning, may explain the observed anticorrelation between sodium and oxygen abundances in globular cluster stars. Its rate is controlled by a number of low-energy resonances and a slowly varying nonresonant component. Three new resonances at Ep=156.2, 189.5, and 259.7 keV have recently been observed and confirmed. However, significant uncertainty on the reaction rate remains due to the nonresonant process and to two suggested resonances at Ep=71 and 105 keV. Here, new 22Ne(p,γ)23Na data with high statistics and low background are reported. Stringent upper limits of 6×10−11 and 7×10−11 eV (90% confidence level), respectively, are placed on the two suggested resonances. In addition, the off-resonant S factor has been measured at unprecedented low energy, constraining the contributions from a subthreshold resonance and the direct capture process. As a result, at a temperature of 0.1 GK the error bar of the 22Ne(p,γ)23Na rate is now reduced by 3 orders of magnitude.
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- 2018
173. Improved astrophysical rate for the 18O(p,α)15N reaction by underground measurements
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Bruno, C.G., primary, Aliotta, M., additional, Descouvemont, P., additional, Best, A., additional, Davinson, T., additional, Bemmerer, D., additional, Boeltzig, A., additional, Broggini, C., additional, Caciolli, A., additional, Cavanna, F., additional, Chillery, T., additional, Ciani, G.F., additional, Corvisiero, P., additional, Depalo, R., additional, Di Leva, A., additional, Elekes, Z., additional, Ferraro, F., additional, Formicola, A., additional, Fülöp, Zs., additional, Gervino, G., additional, Guglielmetti, A., additional, Gustavino, C., additional, Gyürky, Gy., additional, Imbriani, G., additional, Junker, M., additional, Lugaro, M., additional, Marigo, P., additional, Menegazzo, R., additional, Mossa, V., additional, Pantaleo, F.R., additional, Piatti, D., additional, Prati, P., additional, Stöckel, K., additional, Straniero, O., additional, Strieder, F., additional, Szücs, T., additional, Takács, M.P., additional, and Trezzi, D., additional
- Published
- 2019
- Full Text
- View/download PDF
174. Measurement of the C12(C12,p)Na23 cross section near the Gamow energy
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Zickefoose, J., primary, Di Leva, A., additional, Strieder, F., additional, Gialanella, L., additional, Imbriani, G., additional, De Cesare, N., additional, Rolfs, C., additional, Schweitzer, J., additional, Spillane, T., additional, Straniero, O., additional, and Terrasi, F., additional
- Published
- 2018
- Full Text
- View/download PDF
175. This title is unavailable for guests, please login to see more information.
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D'Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., Zavatarelli, S., Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D'Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Published
- 2018
176. This title is unavailable for guests, please login to see more information.
- Author
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Cavanna, F., Depalo, R., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Böltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Scott, D. A., Somorjai, E., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Cavanna, F., Depalo, R., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Böltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Scott, D. A., Somorjai, E., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Abstract
Reported strengths of newly discovered resonances in [F. Cavanna et al., Phys. Rev. Lett. 115, 252501 (2015)] were affected by an error in the analysis. The energy straggling of the ion beam was erroneously neglected. When taking this effect into account, 18-19% higher values are found for the resonance strengths. The astrophysical implications are unchanged.
- Published
- 2018
177. This title is unavailable for guests, please login to see more information.
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Dileva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., Zavatarelli, S., Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Dileva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Published
- 2018
178. This title is unavailable for guests, please login to see more information.
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D'Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., Zavatarelli, S., Ferraro, F., Takács, M. P., Piatti, D., Mossa, V., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Chillery, T., Ciani, G. F., Corvisiero, P., Csedreki, L., Davinson, T., Depalo, R., D'Erasmo, G., Di Leva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marcucci, L. E., Marigo, P., Menegazzo, R., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Published
- 2018
179. This title is unavailable for guests, please login to see more information.
- Author
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Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Dileva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., Zavatarelli, S., Ferraro, F., Takács, M. P., Piatti, D., Cavanna, F., Depalo, R., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Chillery, T., Ciani, G. F., Corvisiero, P., Davinson, T., D’Erasmo, G., Dileva, A., Elekes, Z., Fiore, E. M., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Kochanek, I., Lugaro, M., Marigo, P., Menegazzo, R., Mossa, V., Pantaleo, F. R., Paticchio, V., Perrino, R., Prati, P., Schiavulli, L., Stöckel, K., Straniero, O., Szücs, T., Trezzi, D., and Zavatarelli, S.
- Published
- 2018
180. Recoil separator ERNA: ion beam purification
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Rogalla, D, Theis, S, Campajola, L, D'Onofrio, A, Gialanella, L, Greife, U, Imbriani, G, Ordine, A, Roca, V, Rolfs, C, Romano, M, Sabbarese, C, Schümann, F, Strieder, F, Terrasi, F, and Trautvetter, H.P
- Published
- 1999
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- View/download PDF
181. Measurement of 1323 and 1487 keV resonances in 15N(α,γ ) 19F with the recoil separator ERNA
- Author
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Di Leva, A., Imbriani, G., Buompane, R., Gialanella, L., Best, A., CRISTALLO, Sergio, De Cesare, M., D'Onofrio, A., Duarte, J. G., Gasques, L. R., Morales-Gallegos, L., Pezzella, A., Porzio, G., Rapagnani, D., Roca, V., Romoli, M., Schürmann, D., STRANIERO, Oscar, Terrasi, F., ERNA Collaboration, and ITA
- Abstract
Background: The origin of fluorine is a widely debated issue. Nevertheless, the 15N(α ,γ )19F reaction is a common feature among the various production channels so far proposed. Its reaction rate at relevant temperatures is determined by a number of narrow resonances together with the direct capture and the tails of the two broad resonances at Ec .m .=1323 and 1487 keV. Purpose: The broad resonances widths, Γγ and Γα, have to be measured with adequate precision in order to better determine their contribution to the 15N(α ,γ )19F stellar reaction rate. Methods: Measurement through the direct detection of the 19F recoil ions with the European Recoil separator for Nuclear Astrophysics (ERNA) were performed. The reaction was initiated by a 15N beam impinging onto a 4He windowless gas target. The observed yield of the resonances at Ec .m .=1323 and 1487 keV is used to determine their widths in the α and γ channels. Results: We show that a direct measurement of the cross section of the 15N(α ,γ )19F reaction can be successfully obtained with the recoil separator ERNA, and the widths Γγ and Γα of the two broad resonances have been determined. While a fair agreement is found with earlier determination of the widths of the 1487 keV resonance, a significant difference is found for the 1323 keV resonance Γα. Conclusions: The revision of the widths of the two more relevant broad resonances in the 15N(α ,γ )19F reaction presented in this work is the first step toward a more firm determination of the reaction rate. At present, the residual uncertainty at the temperatures of the 19F stellar nucleosynthesis is dominated by the uncertainties affecting the direct capture component and the 364 keV narrow resonance, both so far investigated only through indirect experiments.
- Published
- 2017
182. 22Ne and 23Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for 22Ne(p,γ)23Na
- Author
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Slemer, A., Marigo, P., Piatti, D., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Bressan, A., Broggini, C., Bruno, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F., Prati, P., Straniero, O., Szücs, T., Takács, M. P., and Trezzi, D.
- Subjects
abundances [stars] ,mass loss [stars] ,carbon [stars] ,abundances ,evolution [stars] ,nuclear reactions [Physical Data and Processes] ,nucleosynthesis ,AGB and post-AGB [stars] - Abstract
We investigate the impact of the new LUNA rate for the nuclear reaction 22Ne(p,γ)23Na on the chemical ejecta of intermediate-mass stars, with particular focus on the thermally- pulsing asymptotic giant branch (TP-AGB) stars that experience hot-bottom burning. To this aim we use the PARSEC and COLIBRI codes to compute the complete evolution, from the pre- main sequence up to the termination of the TP-AGB phase, for a few sets of stellar models with initial masses in the range 3.0 M⊙ − 6.0 M⊙ and three values of metallicity, Zi = 0.0005, Zi = 0.006, and Zi = 0.014. We compare the results of the Ne-Na nucleosynthesis obtained with the new LUNA rate and others available in the literature. We find that the improvement in the astrophysical S-factor obtained with LUNA has remarkably reduced the corresponding nuclear uncertainties in the 22Ne and 23Na AGB yields, which drop from factors of ≃ 10 to just a few for the lowest metallicity models. The uncertainties that still affect the 22Ne and 23Na AGB ejecta are mainly dominated by evolutionary aspects (efficiency of mass-loss, dredge-up events, convection). With the new LUNA data AGB stars with hot-bottom burning produce amounts of 23Na that are in between those predicted with NACRE and Iliadis et al. rates. Finally, we discuss how the LUNA results impact on the hypothesis that invokes primordial massive AGB and super-AGB stars as the main agents of the observed O-Na anticorrelation in Galactic globular clusters. In this context, we derive quantitative constraints on the efficiencies that should characterize other key physical processes (mass loss, third dredge-up, sodium destruction) in order to simultaneously reproduce both the Na-rich, O-poor extreme of the anticorrelation and the observational constraints on the CNO abundance. While best-fitting AGB models can be actually singled out, yet they cannot be taken as a theoretical piece in full support to the AGB hypothesis, as various issues still remain.
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- 2017
183. Measurement of 1323 and 1487 keV resonances in 15N(��, ��)19F with the recoil separator ERNA
- Author
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Di Leva, A., Imbriani, G., Buompane, R., Gialanella, L., Best, A., Cristallo, S., De Cesare, M., D'Onofrio, A., Duarte, J. G., Gasques, L. R., Morales-Gallegos, L., Pezzella, A., Porzio, G., Rapagnani, D., Roca, V., Romoli, M., Sch��rmann, D., Straniero, O., and Terrasi, F.
- Subjects
FOS: Physical sciences ,Nuclear Experiment (nucl-ex) - Abstract
The origin of fluorine is a widely debated issue. Nevertheless, the ^{15}N(��,��)^{19}F reaction is a common feature among the various production channels so far proposed. Its reaction rate at relevant temperatures is determined by a number of narrow resonances together with the DC component and the tails of the two broad resonances at E_{c.m.} = 1323 and 1487 keV. Measurement through the direct detection of the 19F recoil ions with the European Recoil separator for Nuclear Astrophysics (ERNA) were performed. The reaction was initiated by a 15N beam impinging onto a 4He windowless gas target. The observed yield of the resonances at Ec.m. = 1323 and 1487 keV is used to determine their widths in the �� and �� channels. We show that a direct measurement of the cross section of the ^{15}N(��,��)^{19}F reaction can be successfully obtained with the Recoil Separator ERNA, and the widths ��_�� and ��_�� of the two broad resonances have been determined. While a fair agreement is found with earlier determination of the widths of the 1487 keV resonance, a significant difference is found for the 1323 keV resonance ��_�� . The revision of the widths of the two more relevant broad resonances in the 15N(��,��)19F reaction presented in this work is the first step toward a more firm determination of the reaction rate. At present, the residual uncertainty at the temperatures of the ^{19}F stellar nucleosynthesis is dominated by the uncertainties affecting the Direct Capture component and the 364 keV narrow resonance, both so far investigated only through indirect experiments., 8 pages, 11 figures. Accepted for publication in PRC
- Published
- 2017
- Full Text
- View/download PDF
184. 22Ne and23Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for 22Ne(p, γ)23Na
- Author
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Slemer, A., Marigo, P., Piatti, D., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Bressan, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., F\\\', Zs., l\\\', p, Gervino, G., Guglielmetti, A., Gustavino, C., Gy\\\', G., rky, Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Straniero, O., Sz\\\', T., Tak\', M. P., Trezzi, D., Slemer, A., Marigo, P., Piatti, D., Aliotta, M., Bemmerer, D., Best, Andrea, Boeltzig, A., Bressan, A., Broggini, C., Bruno, C. G., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., DI LEVA, Antonino, Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z. s., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, Gianluca, Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Prati, P., Straniero, O., Szücs, T., Takács, M. P., and Trezzi, D.
- Subjects
Stars: mass loss ,abundances – stars: abundances – stars: AGB and post-AGB – stars: carbon – stars: evolution – stars: mass loss ,K-type main-sequence star ,Metallicity ,Astrophysics ,nuclear reactions, nucleosynthesis, abundances, stars: abundances, stars: AGB and post-AGB, stars: carbon, stars: evolution, stars: mass loss ,01 natural sciences ,Settore FIS/05 - Astronomia e Astrofisica ,0103 physical sciences ,Asymptotic giant branch ,Abundances ,010306 general physics ,Ejecta ,010303 astronomy & astrophysics ,Physics ,Stars: abundances ,Stars: AGB and post-AGB ,Order (ring theory) ,Astronomy ,Astronomy and Astrophysics ,Stars ,T Tauri star ,Stars: carbon ,Stars: evolution ,nuclear reactions, nucleosynthesis, abundances – stars: abundances – stars: AGB and post-AGB – stars: carbon – stars: evolution – stars: mass loss ,Astrophysics - Solar and Stellar Astrophysics ,Nuclear reactions ,Nucleosynthesis ,Space and Planetary Science ,13. Climate action ,Stellar mass loss - Abstract
We investigate the impact of the new LUNA rate for the nuclear reaction $^{22}$Ne$(p,\gamma)^{23}$Na on the chemical ejecta of intermediate-mass stars, with particular focus on the thermally-pulsing asymptotic giant branch (TP-AGB) stars that experience hot-bottom burning. To this aim we use the PARSEC and COLIBRI codes to compute the complete evolution, from the pre-main sequence up to the termination of the TP-AGB phase, of a set of stellar models with initial masses in the range $3.0\,M_{\odot} - 6.0\,M_{\odot}$, and metallicities $Z_{\rm i}=0.0005$, $Z_{\rm i}=0.006$, and $Z_{\rm i} = 0.014$. We find that the new LUNA measures have much reduced the nuclear uncertainties of the $^{22}$Ne and $^{23}$Na AGB ejecta, which drop from factors of $\simeq 10$ to only a factor of few for the lowest metallicity models. Relying on the most recent estimations for the destruction rate of $^{23}$Na, the uncertainties that still affect the $^{22}$Ne and $^{23}$Na AGB ejecta are mainly dominated by evolutionary aspects (efficiency of mass-loss, third dredge-up, convection). Finally, we discuss how the LUNA results impact on the hypothesis that invokes massive AGB stars as the main agents of the observed O-Na anti-correlation in Galactic globular clusters. We derive quantitative indications on the efficiencies of key physical processes (mass loss, third dredge-up, sodium destruction) in order to simultaneously reproduce both the Na-rich, O-poor extreme of the anti-correlation, and the observational constraints on the CNO abundance. Results for the corresponding chemical ejecta are made publicly available., Comment: 21 pages, 14 figures, accepted for publication in MNRAS
- Published
- 2017
185. Origin of stardust unveiled by the new LUNA rate of the 17O(p,α)14N reaction
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Lugaro, M., Karakas, A. I., Bruno, C. G., Aliotta, M., Nittler, L. R., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gyürky, C. G. G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Scott, D. A., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Subjects
Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Stardust grains recovered from meteorites provide high-precision snapshots of the isotopic compositions resulting from nuclear reactions in the stars in which they formed. Establishing their stellar sites of origin, however, often proves difficult. One long-standing problem is that a large fraction of meteoritic stardust is predicted to have originated from the late evolutionary phase of stars with initial mass between roughly 4 and 8 solar masses, however, no grains have been found with an isotopic composition that matches that expected in these stars. This problem points to serious gaps in our understanding of the lifecycle of stars and dust in the Galaxy. Here we show that the new, increased rate of the 17O + p → 14N + α nuclear reaction, based on a recent underground experiment, produces 17O/16O isotopic ratios that match those observed in a population of stardust grains, provided that the burning occurs at relatively high temperatures (60–80 million K). These are the temperatures achieved at the base of the convective envelope during the late evolutionary phase of 4 to 8 solar mass stars, which reveals them as the site of origin of the grains. This result provides the first direct evidence that these stars contributed to the dust inventory from which the Solar System formed.
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- 2017
186. The Italian University System: A Cost-Effectiveness Analysis
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Giannino F., Imbriani G., and Marrelli M.
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University System ,Effectiveness Indicators - Abstract
For some time a debate has been promoted both in scientific journals andin the press about the quality of the Italian University system. On the one hand,some authors claim that in Italy we do too little research, leading to a waste ofpublic money. On the other hand, others claim that Italy is basically similar toother comparable countries.This paper aims at presenting some indicators which will help the readers tobetter understand the effectiveness - for each euro spent - of the Italian universitysystem in the international scenario, using the OECD (Organization for EconomicCooperation and Development) and WOS (Web of Science) data sets.
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- 2012
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187. Magnesium isotopes: a tool to understand self-enrichment in globular clusters
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Ventura, P, primary, D’Antona, F, additional, Imbriani, G, additional, Di Criscienzo, M, additional, Dell’Agli, F, additional, and Tailo, M, additional
- Published
- 2018
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- View/download PDF
188. Improved background suppression for radiative capture reactions at LUNA with HPGe and BGO detectors
- Author
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Boeltzig, A, primary, Best, A, additional, Imbriani, G, additional, Junker, M, additional, Aliotta, M, additional, Bemmerer, D, additional, Broggini, C, additional, Bruno, C G, additional, Buompane, R, additional, Caciolli, A, additional, Cavanna, F, additional, Chillery, T, additional, Ciani, G F, additional, Corvisiero, P, additional, Csedreki, L, additional, Davinson, T, additional, deBoer, R J, additional, Depalo, R, additional, Leva, A Di, additional, Elekes, Z, additional, Ferraro, F, additional, Fiore, E M, additional, Formicola, A, additional, Fülöp, Z, additional, Gervino, G, additional, Guglielmetti, A, additional, Gustavino, C, additional, Gyürky, G, additional, Kochanek, I, additional, Menegazzo, R, additional, Mossa, V, additional, Pantaleo, F R, additional, Paticchio, V, additional, Perrino, R, additional, Piatti, D, additional, Prati, P, additional, Schiavulli, L, additional, Stöckel, K, additional, Straniero, O, additional, Strieder, F, additional, Szücs, T, additional, Takács, M P, additional, Trezzi, D, additional, Wiescher, M, additional, and Zavatarelli, S, additional
- Published
- 2018
- Full Text
- View/download PDF
189. Underground study of the O 17 (p, γ) F 18 reaction relevant for explosive hydrogen burning
- Author
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Di Leva A, Scott D, Caciolli A, Formicola A, Strieder F, Aliotta M, Anders M, Bemmerer D, Broggini C, Corvisiero P, Elekes Z, Fülöp Z, Gervino G, Guglielmetti A, Gustavino C, Gyürky G, Imbriani G, José J, Junker M, Laubenstein M, Menegazzo R, Napolitani E, Prati P, Rigato V, Roca V, Somorjai E, Salvo C, Straniero O, Szücs T, Trezzi D., TERRASI, Filippo, Di Leva, A, Scott, D, Caciolli, A, Formicola, A, Strieder, F, Aliotta, M, Anders, M, Bemmerer, D, Broggini, C, Corvisiero, P, Elekes, Z, Fülöp, Z, Gervino, G, Guglielmetti, A, Gustavino, C, Gyürky, G, Imbriani, G, José, J, Junker, M, Laubenstein, M, Menegazzo, R, Napolitani, E, Prati, P, Rigato, V, Roca, V, Somorjai, E, Salvo, C, Straniero, O, Szücs, T, Terrasi, Filippo, and Trezzi, D.
- Published
- 2014
190. Ultra-sensitive gamma-ray spectroscopy set-up for investigating primordial lithium problem
- Author
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Gervino, G., Gustavino, C., Trezzi, D., Aliotta, M., Anders, M., Boeltzig, A., Daniel Bemmerer, Best, A., Broggini, C., Bruno, C., Caciolli, A., Cavanna, F., Corvisiero, P., Davinson, T., Depalo, R., Dileva, A., Elekes, Z., Ferraro, F., Formicola, A., Fulop, Zs, Guglielmetti, A., Gyurky, Gy, Imbriani, G., Junker, M., Menegazzo, R., Prati, P., Scott, D. A., Straniero, O., and Szucs, T.
- Subjects
Gamma spectroscopy ,Underground Physics ,Lithium problem - Published
- 2016
191. Direct measurement of low-energy 22Ne(p,γ)23Na resonances
- Author
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Depalo, R., Cavanna, F., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Ciani, G. F., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Abstract
Background: The 22Ne(p,γ)23Na reaction is the most uncertain process in the neon-sodium cycle of hydrogen burning. At temperatures relevant for nucleosynthesis in asymptotic giant branch stars and classical novae, its uncertainty is mainly due to a large number of predicted but hitherto unobserved resonances at low energy. Purpose: A new direct study of low energy 22Ne(p,γ)23Na resonances has been performed at the Laboratory for Underground Nuclear Astrophysics (LUNA), in the Gran Sasso National Laboratory, Italy. Method: The proton capture on 22Ne was investigated in direct kinematics, delivering an intense proton beam to a 22Ne gas target. γ rays were detected with two high-purity germanium detectors enclosed in a copper and lead shielding suppressing environmental radioactivity. Results: Three resonances at 156.2 keV (ωγ = (1.48 ± 0.10) · 10−7 eV), 189.5 keV (ωγ = (1.87±0.06)·10−6 eV) and 259.7 keV (ωγ = (6.89±0.16)·10−6 eV) proton beam energy, respec- tively, have been observed for the first time. For the levels at Ex = 8943.5, 8975.3, and 9042.4 keV excitation energy corresponding to the new resonances, the γ-decay branching ratios have been precisely measured. Three additional, tentative resonances at 71, 105 and 215 keV proton beam energy, respectively, were not observed here. For the strengths of these resonances, experimental upper limits have been derived that are significantly more stringent than the upper limits reported in the literature. Conclusions: Based on the present experimental data and also previous literature data, an updated thermonuclear reaction rate is provided in tabular and parametric form. The new reaction rate is significantly higher than previous evaluations at temperatures of 0.08-0.3 GK.
- Published
- 2016
192. Direct measurement of low-energy Ne 22 (p,γ) Na 23 resonances
- Author
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Depalo, R., Cavanna, F., Aliotta, M., Anders, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Ciani, G. F., Corvisiero, P., Davinson, T., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z. s., Gervino, Gianpiero, Guglielmetti, A., Gustavino, C., Gyürky, G. y., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Straniero, O., Szücs, T., Takács, M. P., and Trezzi, D.
- Subjects
stellar evolution ,Nuclear Astrophysics ,low energy nuclear physics ,Nuclear Astrophysics, low energy nuclear physics, stellar evolution - Published
- 2016
193. Direct measurement of low-energy 22Ne( p,γ )23Na resonances
- Author
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Depalo, R., Cavanna, Francesca, Aliotta, M., Anders, M., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Bruno, C. G., Caciolli, A., Ciani, G. F., Corvisiero, Pietro, Davinson, T., Di Leva, A., Elekes, Z., Ferraro, Federico, Formicola, A., Fulop, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyurky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, Paolo, Straniero, O., Szucs, T., Takacs, M. P., and Trezzi, D.
- Subjects
nuclear astrophysics, hydrogen burning, Ne-na cycle, cross section measurement, underground ,hydrogen burning ,nuclear astrophysics ,underground ,Ne-na cycle ,cross section measurement - Published
- 2016
194. A windowless hydrogen gas target for the measurement of 7Be(p, γ)8B with the recoil separator ERNA
- Author
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Schürmann D, Di Leva A, GIALANELLA, Lucio, De Cesare M, De Cesare N, Imbriani G, D'ONOFRIO, Antonio, Romano M, Romoli M, TERRASI, Filippo, Schürmann, D, Di Leva, A, Gialanella, Lucio, De Cesare, M, De Cesare, N, Imbriani, G, D'Onofrio, Antonio, Romano, M, Romoli, M, and Terrasi, Filippo
- Published
- 2013
195. This title is unavailable for guests, please login to see more information.
- Author
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Straniero, O., Bruno, C. G., Aliotta, M., Best, A., Boeltzig, A., Bemmerer, D., Broggini, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Cristallo, S., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Piersanti, L., Prati, P., Samorjai, E., Strieder, F., Szucs, T., Takács, M. P., Trezzi, D., Straniero, O., Bruno, C. G., Aliotta, M., Best, A., Boeltzig, A., Bemmerer, D., Broggini, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Cristallo, S., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Piersanti, L., Prati, P., Samorjai, E., Strieder, F., Szucs, T., Takács, M. P., and Trezzi, D.
- Abstract
Context. Material processed by the CNO cycle in stellar interiors is enriched in 17O. When mixing processes from the stellar surface reach these layers, as occurs when stars become red giants and undergo the first dredge up, the abundance of 17O increases. Such an occurrence explains the drop of the 16O/17O observed in RGB stars with mass larger than 1.5 M_\solar. As a consequence, the interstellar medium is continuously polluted by the wind of evolved stars enriched in 17O . Aims. Recently, the Laboratory for Underground Nuclear Astrophysics (LUNA) collaboration released an improved rate of the 17O(p,alpha)14N reaction. In this paper we discuss the impact that the revised rate has on the 16O/17O ratio at the stellar surface and on 17O stellar yields. Methods. We computed stellar models of initial mass between 1 and 20 M_\solar and compared the results obtained by adopting the revised rate of the 17O(p,alpha)14N to those obtained using previous rates. Results. The post-first dredge up 16O/17O ratios are about 20% larger than previously obtained. Negligible variations are found in the case of the second and the third dredge up. In spite of the larger 17O(p,alpha)14N rate, we confirm previous claims that an extra-mixing process on the red giant branch, commonly invoked to explain the low carbon isotopic ratio observed in bright low-mass giant stars, marginally affects the 16O/17O ratio. Possible effects on AGB extra-mixing episodes are also discussed. As a whole, a substantial reduction of 17O stellar yields is found. In particular, the net yield of stars with mass ranging between 2 and 20 M_\solar is 15 to 40% smaller than previously estimated. Conclusions. The revision of the 17O(p,alpha)14N rate has a major impact on the interpretation of the 16O/17O observed in evolved giants, in stardust grains and on the 17O stellar yields.
- Published
- 2017
196. This title is unavailable for guests, please login to see more information.
- Author
-
Slemer, A., Marigo, P., Piatti, D., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Bressan, A., Broggini, C., Bruno, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F., Prati, P., Straniero, O., Szücs, T., Takács, M. P., Trezzi, D., Slemer, A., Marigo, P., Piatti, D., Aliotta, M., Bemmerer, D., Best, A., Boeltzig, A., Bressan, A., Broggini, C., Bruno, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gustavino, C., Gyürky, G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F., Prati, P., Straniero, O., Szücs, T., Takács, M. P., and Trezzi, D.
- Published
- 2017
197. This title is unavailable for guests, please login to see more information.
- Author
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Lugaro, M., Karakas, A. I., Bruno, C. G., Aliotta, M., Nittler, L. R., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gyürky, C. G. G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Scott, D. A., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., Trezzi, D., Lugaro, M., Karakas, A. I., Bruno, C. G., Aliotta, M., Nittler, L. R., Bemmerer, D., Best, A., Boeltzig, A., Broggini, C., Caciolli, A., Cavanna, F., Ciani, G. F., Corvisiero, P., Davinson, T., Depalo, R., Di Leva, A., Elekes, Z., Ferraro, F., Formicola, A., Fülöp, Z., Gervino, G., Guglielmetti, A., Gyürky, C. G. G., Imbriani, G., Junker, M., Menegazzo, R., Mossa, V., Pantaleo, F. R., Piatti, D., Prati, P., Scott, D. A., Straniero, O., Strieder, F., Szücs, T., Takács, M. P., and Trezzi, D.
- Published
- 2017
198. Study of the 6.05 MeV cascade transition in C-12(alpha, gamma)O-16
- Author
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Schurmann D, Di Leva A, Kunz R, Strieder F, De Cesare N, De Cesare M, Fortak K, Imbriani G, Rogalla D, Romano M, GIALANELLA, Lucio, D'ONOFRIO, Antonio, TERRASI, Filippo, Schurmann, D, Di Leva, A, Gialanella, Lucio, Kunz, R, Strieder, F, De Cesare, N, De Cesare, M, D'Onofrio, Antonio, Fortak, K, Imbriani, G, Rogalla, D, Romano, M, and Terrasi, Filippo
- Subjects
Nuclear astrophysics Helium burning α-Capture reaction Cascade transition - Abstract
The radiative capture reaction 12C(α,γ )16O has been investigated in the energy range E = 3.3 to 4.5 MeV. This experiment focused in particular on the cascade transition to the 0+ state at Ex = 6.05 MeV in 16O and was performed by detecting the capture γ -rays with a NaI detector array at the windowless 4He gas target of the recoil mass separator ERNA in coincidence with the 16O ejectiles. The 6.05 MeV transition has been considered recently as a component accounting for up to 15% of the 12C(α,γ )16O total cross section at astrophysical energies. The arrangement of the detector array yielded additional information on the γ -ray multipolarity, i.e. the ratio σE2/σE1, and it was found that the 6.05 MeV transition is entirely E2 in the studied energy range. The results for this transition are analyzed in an R-matrix formalism and extrapolated to the relevant Gamow energy of stellar helium burning, E0 300 keV. In contrast to a previous analysis, the present extrapolation suggests a negligible contribution from this amplitude, S6.05(300) < 1 keV b. Additional data for cascade transitions to excited states at Ex = 6.13, 6.92, and 7.12 MeV, respectively, as well as to the ground state were obtained and the corresponding S factors in the studied energy range are given.
- Published
- 2011
199. Fluorine Abundances in Galactic Asymptotic Giant Branch Stars
- Author
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ABIA C., CUNHA K., CRISTALLO S., DOMINGUEZ I., ERIKSSON K., HINKLE K., IMBRIANI G., R.E.C.I.O. BLANCO A., SMITH V., STRANIERO O., WAHLIN R., GIALANELLA, Lucio, Abia, C., Cunha, K., Cristallo, S., Dominguez, I., Eriksson, K., Hinkle, K., Imbriani, G., Gialanella, Lucio, R. E. C. I. O. BLANCO, A., Smith, V., Straniero, O., and Wahlin, R.
- Subjects
Nucleosynthesis AGB stars ,Nuclear reaction - Abstract
An analysis of the fluorine abundance in Galactic asymptotic giant branch (AGB) carbon stars (24 N-type, 5 SC-type, and 5 J-type) is presented. This study uses the state-of-the-art carbon-rich atmosphere models and improved atomic and molecular line lists in the 2.3 μm region. Significantly lower F abundances are obtained in comparison to previous studies in the literature. This difference is mainly due to molecular blends. In the case of carbon stars of SC-type, differences in the model atmospheres are also relevant. The new F enhancements are now in agreement with the most recent theoretical nucleosynthesis models in low-mass AGB stars, solving the long-standing problem of F in Galactic AGB stars. Nevertheless, some SC-type carbon stars still show larger F abundances than predicted by stellar models. The possibility that these stars are of larger mass is briefly discussed.
- Published
- 2010
200. Resonance strengths in the 17,18O(p,gamma)14,15N reactions and background suppression underground
- Author
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Bruno, C. G., Scott, D. A., Formicola, A., Aliotta, M., Davinson, T., Anders, M., Best, A., Bemmerer, D., Broggini, C., Caciolli, A., Cavanna, F., Corvisiero, P., Depalo, R., Di Leva, A., Elekes, Z., Fulop, Z., Gervino, G., Griffin, C. J., Guglielmetti, A., Gustavino, C., Gyurky, G., Imbriani, G., Junker, M., Menegazzo, R., Napolitani, E., Prati, P., Somorjai, E., Straniero, O., Strieder, F., Szucs, T., and Trezzi, D.
- Subjects
underground physics ,silicon detectors ,nuclear astrophysics ,cross section measurement ,nuclear astrophysics, underground physics, silicon detectors, cross section measurement - Published
- 2015
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