Search

Your search keyword '"I. Dillmann"' showing total 218 results
Start Over Author "I. Dillmann"
218 results on '"I. Dillmann"'

1. Long-term evolution of the neutron rate at the Canfranc Underground Laboratory

Author

S. E. A. Orrigo, J. L. Tain, N. Mont-Geli, A. Tarifeño-Saldivia, L. M. Fraile, M. Grieger, J. Agramunt, A. Algora, D. Bemmerer, F. Calviño, G. Cortés, A. De Blas, I. Dillmann, A. Domínguez Bugarín, R. García, E. Nacher, and A. Tolosa-Delgado

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We report results on the long-term variation of the neutron counting rate at the Canfranc Underground Laboratory, of importance for several low-background experiments installed there, including rare-event searches. The measurement campaign was performed employing the High Efficiency Neutron Spectrometry Array (HENSA) mounted in Hall A and lasted 412 live days. The present study is the first long-term measurement of the neutron rate with sensitivity over a wide range of neutron energies (from thermal up to 0.1 GeV and beyond) performed in any underground laboratory so far. Data on the environmental variables inside the experimental hall (radon concentration, air temperature, air pressure and humidity) were also acquired during all the measurement campaign. We have investigated for the first time the evolution of the neutron rate for different energies of the neutrons and its correlation with the ambient variables.

Published
2022
Full Text
View/download PDF

2. The (6+) isomer in 102Sn revisited: Neutron and proton effective charges close to the double shell closure

Author

H. Grawe, K. Straub, T. Faestermann, M. Górska, C. Hinke, R. Krücken, F. Nowacki, M. Böhmer, P. Boutachkov, H. Geissel, R. Gernhäuser, A. Gottardo, J. Grȩbosz, N. Kurz, Z. Liu, L. Maier, S. Pietri, Zs. Podolyák, K. Steiger, H. Weick, H.J. Wollersheim, P.J. Woods, N. Al-Dahan, N. Alkhomashi, A. Ataç, A. Blazhev, N. Braun, I. Čeliković, T. Davinson, I. Dillmann, C. Domingo-Pardo, P. Doornenbal, G. Farrelly, F. Farinon, G. de France, J. Gerl, N. Goel, T. Habermann, R. Hoischen, R. Janik, M. Karny, A. Kaşkaş, I. Kojouharov, Th. Kröll, M. Lewitowicz, Yu.A. Litvinov, S. Myalski, F. Nebel, S. Nishimura, C. Nociforo, J. Nyberg, A. Parikh, A. Procházka, P.H. Regan, C. Rigollet, H. Schaffner, C. Scheidenberger, S. Schwertel, P.-A. Söderström, S. Steer, A. Stolz, and P. Strmeň

Subjects
Electromagnetic transitions, Shell model, Effective charges near 100Sn, Physics, QC1-999
Abstract

In a high-energy fragmentation experiment at GSI an I=π(6+) isomer and its γ-decay are identified in 102Sn, the two-neutron neighbour of the doubly-magic 100Sn. Its half-life is measured to be T=1/2367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the 100Sn core. From the precise B(E2; 6+→4+) strength and the recently remeasured value for B(E2; 8+→6+) in the two-proton hole neighbour 98Cd effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0ħω space. The results are discussed in comparison to predicted and empirically determined effective operators.

Published
2021
Full Text
View/download PDF

3. Quasi-free neutron and proton knockout reactions from light nuclei in a wide neutron-to-proton asymmetry range

Author

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

Subjects
Physics, QC1-999
Abstract

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

Published
2019
Full Text
View/download PDF

4. Neutron skin and signature of the N = 14 shell gap found from measured proton radii of 17−22N

Author

S. Bagchi, R. Kanungo, W. Horiuchi, G. Hagen, T.D. Morris, S.R. Stroberg, T. Suzuki, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil, I. Dillmann, A. Estradé, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, S. Kaur, R. Knöbel, J. Kurcewicz, Yu.A. Litvinov, M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H.J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, M. Takechi, J. Tanaka, Y. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, and J.S. Winfield

Subjects
Physics, QC1-999
Abstract

A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for 17−22N from charge changing cross section measurements around 900A MeV at GSI. Neutron halo effects are signalled for 22N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at N = 14 arising from the attractive proton–neutron tensor interaction, in good agreement with shell model calculations. Ab initio, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon–nucleon and three-nucleon interaction reproduce well the data approaching the neutron drip-line isotopes but are challenged in explaining the complete isotopic trend of the radii. Keywords: Proton and matter radii, Neutron skin, Magic number, Shell model, Ab initio theory, Radioactive beams

Published
2019
Full Text
View/download PDF

5. β-delayed neutron emission of r-process nuclei at the N = 82 shell closure

Author

O. Hall, T. Davinson, A. Estrade, J. Liu, G. Lorusso, F. Montes, S. Nishimura, V.H. Phong, P.J. Woods, J. Agramunt, D.S. Ahn, A. Algora, J.M. Allmond, H. Baba, S. Bae, N.T. Brewer, C.G. Bruno, R. Caballero-Folch, F. Calviño, P.J. Coleman-Smith, G. Cortes, I. Dillmann, C. Domingo-Pardo, A. Fijalkowska, N. Fukuda, S. Go, C.J. Griffin, R. Grzywacz, J. Ha, L.J. Harkness-Brennan, T. Isobe, D. Kahl, L.H. Khiem, G.G. Kiss, A. Korgul, S. Kubono, M. Labiche, I. Lazarus, J. Liang, Z. Liu, K. Matsui, K. Miernik, B. Moon, A.I. Morales, P. Morrall, M.R. Mumpower, N. Nepal, R.D. Page, M. Piersa, V.F.E. Pucknell, B.C. Rasco, B. Rubio, K.P. Rykaczewski, H. Sakurai, Y. Shimizu, D.W. Stracener, T. Sumikama, H. Suzuki, J.L. Tain, H. Takeda, A. Tarifeño-Saldivia, A. Tolosa-Delgado, M. Wolińska-Cichocka, and R. Yokoyama

Subjects
β-delayed neutron emission, r-process, Physics, QC1-999
Abstract

Theoretical models of β-delayed neutron emission are used as crucial inputs in r-process calculations. Benchmarking the predictions of these models is a challenge due to a lack of currently available experimental data. In this work the β-delayed neutron emission probabilities of 33 nuclides in the important mass regions south and south-west of 132Sn are presented, 16 for the first time. The measurements were performed at RIKEN using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The P1n values presented constrain the predictions of theoretical models in the region, affecting the final abundance distribution of the second r-process peak at A≈130.

Published
2021
Full Text
View/download PDF

6. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author

I. Syndikus, M. Petri, A.O. Macchiavelli, S. Paschalis, C.A. Bertulani, T. Aumann, H. Alvarez-Pol, L. Atar, S. Beceiro-Novo, J. Benlliure, J.M. Boillos, K. Boretzky, M.J.G. Borge, B.A. Brown, M. Caamaño, C. Caesar, E. Casarejos, W. Catford, J. Cederkall, S. Chakraborty, L.V. Chulkov, D. Cortina-Gil, E. Cravo, R. Crespo, U. Datta Pramanik, I. Dillmann, P. Díaz Fernández, Z. Elekes, J. Enders, F. Farinon, L.M. Fraile, D. Galaviz, H. Geissel, R. Gernhäuser, P. Golubev, K. Göbel, M. Heil, M. Heine, A. Heinz, A. Henriques, M. Holl, H.T. Johansson, B. Jonson, N. Kalantar-Nayestanaki, R. Kanungo, A. Kelic-Heil, T. Kröll, N. Kurz, C. Langer, T. Le Bleis, J. Machado, J. Marganiec-Gałązka, E. Nacher, T. Nilsson, C. Nociforo, V. Panin, A. Perea, S.B. Pietri, R. Plag, A. Rahaman, R. Reifarth, A. Revel, G. Ribeiro, C. Rigollet, D.M. Rossi, D. Savran, H. Scheit, H. Simon, O. Sorlin, O. Tengblad, Y. Togano, M. Vandebrouck, V. Volkov, F. Wamers, C. Wheldon, G.L. Wilson, J.S. Winfield, H. Weick, P. Woods, D. Yakorev, M. Zhukov, A. Zilges, and K. Zuber

Subjects
Quasi-free scattering reactions, Magic numbers, Spin-orbit splitting, Tensor force, Shell evolution, Exotic nuclei, Physics, QC1-999
Abstract

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z=6 spin-orbit shell gap towards the neutron dripline. To do so, we employed NA(p,2p)CA−1 quasi-free scattering reactions to measure the proton component of the 21+ state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1p1/2−1p3/2 spin-orbit splitting, at variance to recent claims for a prevalent Z=6 magic number towards the neutron dripline.

Published
2020
Full Text
View/download PDF

7. Halo structure of 8B determined from intermediate energy proton elastic scattering in inverse kinematics

Author

G.A. Korolev, A.V. Dobrovolsky, A.G. Inglessi, G.D. Alkhazov, P. Egelhof, A. Estradé, I. Dillmann, F. Farinon, H. Geissel, S. Ilieva, Y. Ke, A.V. Khanzadeev, O.A. Kiselev, J. Kurcewicz, X.C. Le, Yu.A. Litvinov, G.E. Petrov, A. Prochazka, C. Scheidenberger, L.O. Sergeev, H. Simon, M. Takechi, S. Tang, V. Volkov, A.A. Vorobyov, H. Weick, and V.I. Yatsoura

Subjects
Physics, QC1-999
Abstract

The absolute differential cross section for small-angle proton elastic scattering on the proton-rich 8B nucleus has been measured in inverse kinematics for the first time. The experiment was performed using a secondary radioactive beam with an energy of 0.7 GeV/u at GSI, Darmstadt. The active target, namely hydrogen-filled time projection ionization chamber IKAR, was used to measure the energy, angle and vertex point of the recoil protons. The scattering angle of the projectiles was simultaneously determined by the tracking detectors. The measured differential cross section is analyzed on the basis of the Glauber multiple scattering theory using phenomenological nuclear-density distributions with two free parameters. The radial density distribution deduced for 8B exhibits a halo structure with the root-mean-square (rms) matter radius Rm=2.58(6) fm and the rms halo radius Rh=4.24(25) fm. The results on 8B are compared to those on the mirror nucleus 8Li investigated earlier by the same method. A comparison is also made with previous experimental results and theoretical predictions for both nuclei. Keywords: 8B, Proton halo, Proton elastic scattering, Inverse kinematics

Published
2018
Full Text
View/download PDF

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

Author

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

Subjects
Physics, QC1-999
Abstract

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

Published
2019
Full Text
View/download PDF

9. First measurement of isoscalar giant resonances in a stored-beam experiment

Author

J.C. Zamora, T. Aumann, S. Bagchi, S. Bönig, M. Csatlós, I. Dillmann, C. Dimopoulou, P. Egelhof, V. Eremin, T. Furuno, H. Geissel, R. Gernhäuser, M.N. Harakeh, A.-L. Hartig, S. Ilieva, N. Kalantar-Nayestanaki, O. Kiselev, H. Kollmus, C. Kozhuharov, A. Krasznahorkay, Th. Kröll, M. Kuilman, S. Litvinov, Yu.A. Litvinov, M. Mahjour-Shafiei, M. Mutterer, D. Nagae, M.A. Najafi, C. Nociforo, F. Nolden, U. Popp, C. Rigollet, S. Roy, C. Scheidenberger, M. von Schmid, M. Steck, B. Streicher, L. Stuhl, M. Thürauf, T. Uesaka, H. Weick, J.S. Winfield, D. Winters, P.J. Woods, T. Yamaguchi, K. Yue, and J. Zenihiro

Subjects
Physics, QC1-999
Abstract

A new technique developed for measuring nuclear reactions at low momentum transfer with stored beams in inverse kinematics was successfully used to study isoscalar giant resonances. The experiment was carried out at the experimental heavy-ion storage ring (ESR) at the GSI facility using a stored 58Ni beam at 100 MeV/u and an internal helium gas-jet target. In these measurements, inelastically scattered α-recoils at very forward center-of-mass angles (θcm≤1.5°) were detected with a dedicated setup, including ultra-high vacuum compatible detectors. Experimental results indicate a dominant contribution of the isoscalar giant monopole resonance at this very forward angular range. It was found that the monopole contribution exhausts 79−11+12% of the energy-weighted sum rule (EWSR), which agrees with measurements performed in normal kinematics. This opens up the opportunity to investigate the giant resonances in a large domain of unstable and exotic nuclei in the near future. It is a fundamental milestone towards new nuclear reaction studies with stored ion beams. Keywords: Storage ring, Inverse kinematics, Isoscalar giant resonances

Published
2016
Full Text
View/download PDF

10. First Evidence of Axial Shape Asymmetry and Configuration Coexistence in Zn74 : Suggestion for a Northern Extension of the N=40 Island of Inversion

Author

M. Rocchini, P. E. Garrett, M. Zielińska, S. M. Lenzi, D. D. Dao, F. Nowacki, V. Bildstein, A. D. MacLean, B. Olaizola, Z. T. Ahmed, C. Andreoiu, A. Babu, G. C. Ball, S. S. Bhattacharjee, H. Bidaman, C. Cheng, R. Coleman, I. Dillmann, A. B. Garnsworthy, S. Gillespie, C. J. Griffin, G. F. Grinyer, G. Hackman, M. Hanley, A. Illana, S. Jones, A. T. Laffoley, K. G. Leach, R. S. Lubna, J. McAfee, C. Natzke, S. Pannu, C. Paxman, C. Porzio, A. J. Radich, M. M. Rajabali, F. Sarazin, K. Schwarz, S. Shadrick, S. Sharma, J. Suh, C. E. Svensson, D. Yates, and T. Zidar

Subjects
General Physics and Astronomy
Published
2023
Full Text
View/download PDF

11. Storage, Accumulation and Deceleration of Secondary Beams for Nuclear Astrophysics

Author

J. Glorius, Yu. A. Litvinov, M. Aliotta, F. Amjad, B. Brückner, C.G. Bruno, R. Chen, T. Davinson, S.F. Dellmann, T. Dickel, I. Dillmann, P. Erbacher, O. Forstner, H. Geissel, C.J. Griffin, R. Grisenti, A. Gumberidze, E. Haettner, R. Hess, P.-M. Hillenbrand, C. Hornung, R. Joseph, B. Jurado, E. Kazanseva, R. Knöbel, D. Kostyleva, C. Kozhuharov, N. Kuzminchuk, C. Langer, G. Leckenby, C. Lederer-Woods, M. Lestinsky, S. Litvinov, B. Löher, B. Lorenz, E. Lorenz, J. Marsh, E. Menz, T. Morgenroth, I. Mukha, N. Petridis, U. Popp, A. Psaltis, S. Purushothaman, R. Reifarth, E. Rocco, P. Roy, M.S. Sanjari, C. Scheidenberger, M. Sguazzin, R.S. Sidhu, U. Spillmann, M. Steck, T. Stöhlker, J.A. Swartz, Y.K. Tanaka, H. Törnqvist, L. Varga, D. Vescovi, H. Weick, M. Weigand, P.J. Woods, T. Yamaguchi, and J. Zhao

Subjects
Storage rings, Nuclear and High Energy Physics, Rare ion beans, Physics - Instrumentation and Detectors, In-flight production, FOS: Physical sciences, Nuclear reaction, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation
Abstract

Low-energy investigations on rare ion beams are often limited by the available intensity and purity of the ion species in focus. Here, we present the first application of a technique that combines in-flight production at relativistic energies with subsequent secondary beam storage, accumulation and finally deceleration to the energy of interest. Using the FRS and ESR facilities at GSI, this scheme was pioneered to provide a secondary beam of $^{118}$Te$^{52+}$ for the measurement of nuclear proton-capture at energies of 6 and 7 MeV/u. The technique provided stored beam intensities of about $10^6$ ions at high purity and brilliance, representing a major step towards low-energy nuclear physics studies using rare ion beams.

Published
2023
Full Text
View/download PDF

12. First observation of isomeric states in Zr111, Nb113 , and Mo115

Author

J. Wu, S. Nishimura, P.-A. Söderström, A. Algora, J. J. Liu, V. H. Phong, Y. Q. Wu, F. R. Xu, J. Agramunt, D. S. Ahn, T. A. Berry, C. G. Bruno, J. J. Bundgaard, R. Caballero-Folch, A. C. Dai, T. Davinson, I. Dillmann, A. Estrade, A. Fijałkowska, N. Fukuda, S. Go, R. K. Grzywacz, T. Isobe, S. Kubono, G. Lorusso, K. Matsui, A. I. Morales, N. Nepal, S. E. A. Orrigo, B. C. Rasco, K. P. Rykaczewski, H. Sakurai, Y. Shimizu, D. W. Stracener, T. Sumikama, H. Suzuki, J. L. Tain, H. Takeda, A. Tarifeño-Saldivia, A. Tolosa-Delgado, M. Wolińska-Cichocka, and R. Yokoyama

Published
2022
Full Text
View/download PDF

13. β -Delayed One and Two Neutron Emission Probabilities Southeast of Sn132 and the Odd-Even Systematics in r -Process Nuclide Abundances

Author

V. H. Phong, S. Nishimura, G. Lorusso, T. Davinson, A. Estrade, O. Hall, T. Kawano, J. Liu, F. Montes, N. Nishimura, R. Grzywacz, K. P. Rykaczewski, J. Agramunt, D. S. Ahn, A. Algora, J. M. Allmond, H. Baba, S. Bae, N. T. Brewer, C. G. Bruno, R. Caballero-Folch, F. Calviño, P. J. Coleman-Smith, G. Cortes, I. Dillmann, C. Domingo-Pardo, A. Fijalkowska, N. Fukuda, S. Go, C. J. Griffin, J. Ha, L. J. Harkness-Brennan, T. Isobe, D. Kahl, L. H. Khiem, G. G. Kiss, A. Korgul, S. Kubono, M. Labiche, I. Lazarus, J. Liang, Z. Liu, K. Matsui, K. Miernik, B. Moon, A. I. Morales, P. Morrall, N. Nepal, R. D. Page, M. Piersa-Siłkowska, V. F. E. Pucknell, B. C. Rasco, B. Rubio, H. Sakurai, Y. Shimizu, D. W. Stracener, T. Sumikama, H. Suzuki, J. L. Tain, H. Takeda, A. Tarifeño-Saldivia, A. Tolosa-Delgado, M. Wolińska-Cichocka, P. J. Woods, and R. Yokoyama

Subjects
General Physics and Astronomy
Published
2022
Full Text
View/download PDF

14. Proton Distribution Radii of O16–24 : Signatures of New Shell Closures and Neutron Skin

Author

S. Kaur, R. Kanungo, W. Horiuchi, G. Hagen, J. D. Holt, B. S. Hu, T. Miyagi, T. Suzuki, F. Ameil, J. Atkinson, Y. Ayyad, S. Bagchi, D. Cortina-Gil, I. Dillmann, A. Estradé, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, R. Knöbel, J. Kurcewicz, Yu. A. Litvinov, M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, T. Otsuka, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, M. Takechi, J. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, and J. S. Winfield

Subjects
General Physics and Astronomy
Published
2022
Full Text
View/download PDF

15. First Report of a Doublet 2209-keV State in $^{100}$Zr

Author

D. Kalaydjieva, P.E. Garrett, H. Bidaman, M. Rocchini, M. Zielińska, W. Korten, V. Bildstein, S. Pannu, Z. Ahmed, C. Andreoiu, D. Annen, G.C. Ball, G. Benzoni, S.S. Bhattacharjee, S. Buck, R.J. Coleman, S. Devinyak, I. Dillmann, R. Caballero-Folch, F.H. Garcia, A.B. Garnsworthy, B. Greaves, C.J. Griffin, G.F. Grinyer, E. Gyabeng Fuakye, G. Hackman, D. Hymers, R. Kanungo, K. Kapoor, E. Kasanda, N. Marchini, K.M. Mashtakov, A. Nannini, C. Natzke, B. Olaizola, K. Ortner, C.M. Petrache, M. Polettini, A.J. Radich, N. Saei, M. Satrazani, M. Siciliano, M. Singh, P. Spagnoletti, C.E. Svensson, D.A. Torres, R. Umashankar, V. Vedia, T. Zidar, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract

International audience; A β-decay experiment aiming at investigation of the low-spin structure of 100Zr was performed using the GRIFFIN spectrometer at TRIUMFISAC. Based on the obtained data, a new 2 + state is postulated which is degenerate in energy with the established (5+) level at 2209 keV.

Published
2022
Full Text
View/download PDF

17. Improved high-precision mass measurements of mid-shell neon isotopes

Author

A. Jacobs, C. Andreoiu, J. Bergmann, T. Brunner, T. Dickel, I. Dillmann, E. Dunling, J. Flowerdew, L. Graham, G. Gwinner, Z. Hockenbery, W.J. Huang, B. Kootte, Y. Lan, K.G. Leach, E. Leistenschneider, D. Lunney, E.M. Lykiardopoulou, V. Monier, I. Mukul, S.F. Paul, W.R. Plaß, M.P. Reiter, C. Scheidenberger, R. Thompson, J.L. Tracy, C. Will, M.E. Wieser, J. Dilling, and A.A. Kwiatkowski

Subjects
Nuclear and High Energy Physics
Published
2023
Full Text
View/download PDF

18. β-Delayed One and Two Neutron Emission Probabilities Southeast of ^{132}Sn and the Odd-Even Systematics in r-Process Nuclide Abundances

Author

V H, Phong, S, Nishimura, G, Lorusso, T, Davinson, A, Estrade, O, Hall, T, Kawano, J, Liu, F, Montes, N, Nishimura, R, Grzywacz, K P, Rykaczewski, J, Agramunt, D S, Ahn, A, Algora, J M, Allmond, H, Baba, S, Bae, N T, Brewer, C G, Bruno, R, Caballero-Folch, F, Calviño, P J, Coleman-Smith, G, Cortes, I, Dillmann, C, Domingo-Pardo, A, Fijalkowska, N, Fukuda, S, Go, C J, Griffin, J, Ha, L J, Harkness-Brennan, T, Isobe, D, Kahl, L H, Khiem, G G, Kiss, A, Korgul, S, Kubono, M, Labiche, I, Lazarus, J, Liang, Z, Liu, K, Matsui, K, Miernik, B, Moon, A I, Morales, P, Morrall, N, Nepal, R D, Page, M, Piersa-Siłkowska, V F E, Pucknell, B C, Rasco, B, Rubio, H, Sakurai, Y, Shimizu, D W, Stracener, T, Sumikama, H, Suzuki, J L, Tain, H, Takeda, A, Tarifeño-Saldivia, A, Tolosa-Delgado, M, Wolińska-Cichocka, P J, Woods, and R, Yokoyama

Abstract

The β-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. β-delayed two-neutron emission (β2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured. Weak β2n was also detected from ^{137,138}Sn. Our results highlight the effect of the N=82 and Z=50 shell closures on β-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and γ emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P_{1n} and P_{2n} have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in r-process-enhanced (r-II) stars is also better reproduced using our new data.

Published
2022

19. Half-life Measurement Using Implant-\((\beta -\gamma )\) Time Correlations in the Region of Neutron-rich Lanthanides

Author

A. Vitéz-Sveiczer, S. Kovács, G.G. Kiss, Y. Saito, A. Tarifeño-Saldivia, M. Pallas, J.L. Tain, I. Dillmann, J. Agramunt, A. Algora, C. Domingo-Pardo, A. Estrade, C. Appleton, J.M. Allmond, P. Aguilera, H. Baba, N.T. Brewer, C. Bruno, R. Caballero-Folch, F. Calvino, P.J. Coleman-Smith, G. Cortes, T. Davinson, N. Fukuda, Z. Ge, S. Go, C.J. Griffin, R.K. Grzywacz, O. Hall, A. Horváth, J. Ha, L.J. Harkness-Brennan, T. Isobe, D. Kahl, T.T. King, A. Korgul, R. Krücken, S. Kubono, M. Labiche, J. Liu, J. Liang, M. Madurga, K. Miernik, F. Molina, A.I. Morales, M.R. Mumpower, E. Nacher, A. Navarro, N. Nepal, S. Nishimura, M. Piersa-Siłkowska, V. Phong, B.C. Rasco, B. Rubio, K.P. Rykaczewski, J. Romero-Barrientos, H. Sakurai, L. Sexton, Y. Shimizu, M. Singh, T. Sprouse, T. Sumikama, R. Surman, H. Suzuki, T.N. Szegedi, H. Takeda, A. Tolosa-Delgado, K. Wang, M. Wolinska-Cichocka, P. Woods, R. Yokoyama, and Z. Xu

Subjects
General Physics and Astronomy
Published
2023
Full Text
View/download PDF

20. Proton capture on stored radioactive 118Te ions

Author

S. F. Dellmann, J. Glorius, Y. A. Litvinov, R. Reifarth, K. Al-Khasawneh, M. Aliotta, L. Bott, B. Brückner, C. Bruno, R. J. Chen, T. Davinson, T. Dickel, I Dillmann, D. Dmytriev, P. Erbacher, D. Freire-Fernández, O. Forstner, H. Geissel, K. Göbel, C. J. Griffin, R. Grisenti, A. Gumberidze, E. Haettner, S. Hagmann, M. Heil, R. Heß, P.-M. Hillenbrand, R. Joseph, B. Jurado, C. Kozhuharov, I. Kulikov, B. Löher, C. Langer, G. Leckenby, C. Lederer-Woods, M. Lestinsky, S. Litvinov, B. A. Lorenz, E. Lorenz, J. Marsh, E. Menz, T. Morgenroth, N. Petridis, J. Pibernat, U. Popp, A. Psaltis, S. Sanjari, C. Scheidenberger, M. Sguazzin, R. S. Sidhu, U. Spillmann, M. Steck, T. Stöhlker, A. Surzhykov, J. A. Swartz, H. Törnqvist, L. Varga, D. Vescovi, H. Weick, M. Weigand, P. Woods, Y. Xing, and T. Yamaguchi

Subjects
General Medicine
Abstract

Experimental determination of the cross sections of proton capture on radioactive nuclei is extremely difficult. Therefore, it is of substantial interest for the understanding of the production of the p-nuclei. For the first time, a direct measurement of proton-capture cross sections on stored, radioactive ions became possible in an energy range of interest for nuclear astrophysics. The experiment was performed at the Experimental Storage Ring (ESR) at GSI by making use of a sensitive method to measure (p,γ) and (p,n) reactions in inverse kinematics. These reaction channels are of high relevance for the nucleosyn-thesis processes in supernovae, which are among the most violent explosions in the universe and are not yet well understood. The cross section of the 118Te(p,γ) reaction has been measured at energies of 6 MeV/u and 7 MeV/u. The heavy ions interacted with a hydrogen gas jet target. The radiative recombination process of the fully stripped 118Te ions and electrons from the hydrogen target was used as a luminosity monitor. An overview of the experimental method and preliminary results from the ongoing analysis will be presented.

Published
2023
Full Text
View/download PDF

21. Indirect measurements of neutron-induced reaction cross sections at heavy-ion storage rings

Author

M. Sguazzin, B. Jurado, J. Pibernat, J. A. Swartz, M. Grieser, J. Glorius, Yu. A. Litvinov, R. Reifarth, K. Blaum, P. Alfaurt, P. Ascher, L. Audouin, C. Berthelot, B. Blank, B. Bruckner, S. Dellmann, I. Dillmann, C. Domingo-Pardo, M. Dupuis, P. Erbacher, M. Flayol, O. Forstner, D. Freire-Fernández, M. Gerbaux, J. Giovinazzo, S. Grévy, C. J. Griffin, A. Gumberidze, S. Heil, A. Heinz, D. Kurtulgil, G. Leckenby, S. Litvinov, B. Lorentz, V. Méot, J. Michaud, S. Perard, N. Petridis, U. Popp, D. Ramos, M. Roche, M.S. Sanjari, R.S. Sidhu, U. Spillmann, M. Steck, Th. Stöhlker, B. Thomas, L. Thulliez, and M. Versteegen

Subjects
General Medicine
Abstract

Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars and for applications in nuclear technology. However, their measurement is very complicated due to the radioactivity of the targets involved. We propose to circumvent this problem by using the surrogate reaction method in inverse kinematics, where the nucleus formed in the neutron- induced reaction of interest is produced by a reaction involving a radioactive heavy-ion beam and a stable, light target nucleus. The probabilities as a function of the compound-nucleus excitation energy for γ-ray emission, neutron emission and fission, which can be measured with the surrogate reaction, are particularly useful to constrain model parameters and to obtain more accurate predictions of the neutron-induced reaction cross sections of interest. Yet, the full development of the surrogate method is hampered by numerous long- standing target issues, which can be solved by combining surrogate reactions with the unique and largely unexplored possibilities at heavy-ion storage rings. In this contribution, we describe the developments we are carrying out to measure for the first time simultaneously γ-ray emission, neutron emission and fission probabilities at the storage rings of the GSI/FAIR facility. In particular, we will present the first results of the proof of principle experiment, which we performed in June 2022 at the Experimental Storage Ring (ESR) of GSI/FAIR.

Published
2023
Full Text
View/download PDF

22. Study of decay properties for Ba to Nd nuclei relevant for the formation of the r-process rare-earth peak (A∼160)

Author

M. Pallàs, A. Tarifeño-Saldivia, G. G. Kiss, J. L. Tain, A. Tolosa-Delgado, A. Vitéz-Sveiczer, F. Calviño, J. Agramunt, P. Aguilera, A. Algora, J. M. Allmond, H. Baba, N. T. Brewer, R. Caballero-Folch, P. J. Coleman-Smith, G. Cortes, T. Davinson, I. Dillmann, C. Domingo-Pardo, A. Estrade, N. Fukuda, S. Go, C. J. Griffin, R. K. Grzywacz, O. Hall, L. J. Harkness-Brennan, T. Isobe, D. Kahl, T. T. King, A. Korgul, S. Kovács, S. Kubono, M. Labiche, J. Liu, M. Madurga, K. Miernik, F. Molina, N. Mont-Geli, A. I. Morales, E. Nácher, A. Navarro, N. Nepal, S. Nishimura, M. Piersa-Silkowska, V. Phong, B. C. Rasco, J. Romero-Barrientos, B. Rubio, K. P. Rykaczewski, Y. Saito, H. Sakurai, Y. Shimizu, M. Singh, T. Sumikama, H. Suzuki, T. N. Szegedi, H. Takeda, K. Wang, M. Wolińska-Cichocka, P. J. Woods, and R. Yokoyama

Subjects
General Medicine
Abstract

At the RIKEN Nishina Center, exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured. This work reports their half-lives (T1/2) and β-delayed neutron-emission probabilities (Pxn). The setup consisted of the BigRIPS in-flight separator for particle identification, the Advanced Implantation Detector Array (AIDA) for ions and β detection, and the BRIKEN neutron counter for neutron detection. Using this arrangement, 4 new T1/2 and 14 new P1n were measured. Furthermore, 38 T1/2 and 2 P1n values were remeasured, decreasing the uncertainties for some of them. In addition to improving predictions of nucleosynthesis models that describe the production of the rare-earth peak at A ∼ 160 via the r-process, these additional experimental data should help to constrain theoretical models for calculations of T1/2 and Pxn in this region.

Published
2023
Full Text
View/download PDF

23. Mass measurements of Ga60–63 reduce x-ray burst model uncertainties and extend the evaluated T=1 isobaric multiplet mass equation

Author

S. F. Paul, J. Bergmann, J. D. Cardona, K. A. Dietrich, E. Dunling, Z. Hockenbery, C. Hornung, C. Izzo, A. Jacobs, A. Javaji, B. Kootte, Y. Lan, E. Leistenschneider, E. M. Lykiardopoulou, I. Mukul, T. Murböck, W. S. Porter, R. Silwal, M. B. Smith, J. Ringuette, T. Brunner, T. Dickel, I. Dillmann, G. Gwinner, M. MacCormick, M. P. Reiter, H. Schatz, N. A. Smirnova, J. Dilling, and A. A. Kwiatkowski

Subjects
010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences
Published
2021
Full Text
View/download PDF

24. Measurement of the neutron flux at the Canfranc Underground Laboratory with HENSA

Author

S E A Orrigo, J L Tain, N Mont-Geli, A Tarifeño-Saldivia, L M Fraile, M Grieger, J Agramunt, A Algora, D Bemmerer, F Calviño, G Cortés, A DeBlas, I Dillmann, A Domínguez Bugarín, R García, E Nacher, and A Tolosa

Subjects
History, High Energy Physics - Experiment (hep-ex), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, Computer Science Applications, Education, High Energy Physics - Experiment
Abstract

We have performed a long-term measurement of the neutron flux with the High Efficiency Neutron Spectrometry Array HENSA in the Hall A of the Canfranc Underground Laboratory. The Hall A measurement campaign lasted from October 2019 to March 2021, demonstrating an excellent stability of the HENSA setup. Preliminary results on the neutron flux from this campaign are presented for the first time. In Phase 1 (113 live days) a total neutron flux of 1.66(2) $\times$10$^{-5}$ cm$^{-2}$ s$^{-1}$ is obtained. Our results are in good agreement with those from our previous shorter measurement where a reduced experimental setup was employed., Proceedings of the 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021)

Published
2021

25. Nuclear-matter distribution in the proton-rich nuclei 7Be and 8B from intermediate energy proton elastic scattering in inverse kinematics

Author

Alexei Khanzadeev, A. V. Dobrovolsky, G.A. Korolev, Yu. A. Litvinov, V. Volkov, Alfredo Estrade, P. Egelhof, J. Kurcewicz, G. E. Petrov, G. D. Alkhazov, Y. Ke, Herbert A. Simon, L.O. Sergeev, I. Dillmann, Hans Geissel, A. Prochazka, S. Tang, An.A. Vorobyov, S. Ilieva, F. Farinon, V. I. Yatsoura, O.A. Kiselev, Helmut Weick, X.C. Le, A.G. Inglessi, Gianluca Colò, C. Scheidenberger, and M. Takechi

Subjects
Elastic scattering, Physics, Nuclear and High Energy Physics, Nuclear Theory, Proton, 010308 nuclear & particles physics, Scattering, FOS: Physical sciences, Radius, Nuclear matter, 01 natural sciences, Nuclear Theory (nucl-th), Nuclear physics, Recoil, 0103 physical sciences, Halo, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Glauber
Abstract

Absolute differential cross sections for elastic $p^7$Be and $p^8$B small-angle scattering were measured in inverse kinematics at an energy of 0.7 GeV/u at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR was used as an active target to detect the recoil protons. The projectile tracking and isotope identification were performed with multi-wire proportional chambers and scintillation detectors. The measured cross sections were analysed using the Glauber multiple-scattering theory. The root-mean-square (rms) nuclear matter radii $R_{\rm m} = 2.42 (4)$ fm for $^7$Be and $R_{\rm m} = 2.58 (6)$ fm for $^8$B were obtained. The radial density distribution deduced for $^8$B exhibits a proton halo structure with the rms halo radius $R_{\rm h} = 4.24 (25)$ fm. A comparison of the deduced experimental radii is displayed with existing experimental and theoretical data., 18 pages, 6 figures. arXiv admin note: text overlap with arXiv:1803.02044

Published
2019
Full Text
View/download PDF

26. Measuring the β-decay Properties of Neutron-rich Exotic Pm, Sm, Eu, and Gd Isotopes to Constrain the Nucleosynthesis Yields in the Rare-earth Region

Author

G. G. Kiss, A. Vitéz-Sveiczer, Y. Saito, A. Tarifeño-Saldivia, M. Pallas, J. L. Tain, I. Dillmann, J. Agramunt, A. Algora, C. Domingo-Pardo, A. Estrade, C. Appleton, J. M. Allmond, P. Aguilera, H. Baba, N. T. Brewer, C. Bruno, R. Caballero-Folch, F. Calvino, P. J. Coleman-Smith, G. Cortes, T. Davinson, N. Fukuda, Z. Ge, S. Go, C. J. Griffin, R. K. Grzywacz, O. Hall, A. Horváth, J. Ha, L. J. Harkness-Brennan, T. Isobe, D. Kahl, T. T. King, A. Korgul, S. Kovács, R. Krücken, S. Kubono, M. Labiche, J. Liu, J. Liang, M. Madurga, K. Miernik, F. Molina, A. I. Morales, M. R. Mumpower, E. Nacher, A. Navarro, N. Nepal, S. Nishimura, M. Piersa-Siłkowska, V. Phong, B. C. Rasco, B. Rubio, K. P. Rykaczewski, J. Romero-Barrientos, H. Sakurai, L. Sexton, Y. Shimizu, M. Singh, T. Sprouse, T. Sumikama, R. Surman, H. Suzuki, T. N. Szegedi, H. Takeda, A. Tolosa, K. Wang, M. Wolinska-Cichocka, P. Woods, R. Yokoyama, Z. Xu, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group

Subjects
Física [Àrees temàtiques de la UPC], Space and Planetary Science, Astronomy and Astrophysics, Stars, Nucleosynthesis, Estels, Nucleosíntesi
Abstract

The β-delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes of Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The existing β-decay half-life (T 1/2) database was significantly increased toward more neutron-rich isotopes, and uncertainties for previously measured values were decreased. The new data not only constrain the theoretical predictions of half-lives and β-delayed neutron-emission probabilities, but also allow for probing the mechanisms of formation of the high-mass wing of the rare-earth peak located at A ≈ 160 in the r-process abundance distribution through astrophysical reaction network calculations. An uncertainty quantification of the calculated abundance patterns with the new data shows a reduction of the uncertainty in the rare-earth peak region. The newly introduced variance-based sensitivity analysis method offers valuable insight into the influence of important nuclear physics inputs on the calculated abundance patterns. The analysis has identified the half-lives of 168Sm and of several gadolinium isotopes as some of the key variables among the current experimental data to understand the remaining abundance uncertainty at A = 167–172.

Published
2022
Full Text
View/download PDF

27. Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated He3 counters

Author

Stefan E. Müller, J. L. Tain, Ulli Köster, D. Jordan, L. M. Fraile, Marcel Grieger, Detlev Degering, Tamás Szücs, Jorge Agramunt, Kai Zuber, T. Hensel, Daniel Bemmerer, I. Dillmann, and M. Marta

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Detector, 01 natural sciences, 7. Clean energy, Spectral line, Nuclear physics, Flux (metallurgy), Neutron flux, 0103 physical sciences, Electromagnetic shielding, Energy spectrum, Neutron, 010306 general physics
Abstract

Ambient neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He-3 neutron counters are used for a detailed study of the ambient neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to neutrons of energies higher than 10 MeV. For each He-3 counter moderator assembly, the energy-dependent neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the neutron energy spectrum from 10(-9) to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61 +/- 0.05), (1.96 +/- 0.15), and (4.6 +/- 0.4) x 10(-4) cm(-2) s(-1), respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.

Published
2020
Full Text
View/download PDF

28. Neutron skin and signature of the $N$ = 14 shell gap found from measured proton radii of $^{17-22}$N

Author

A. Evdokimov, J. Atkinson, Hooi Jin Ong, Gaute Hagen, S. Pietri, F. Farinon, Yu. A. Litvinov, S. Bagchi, M. Marta, Branislav Sitar, A. Prochazka, Satbir Kaur, M. Mostazo, M. Takechi, Hans Geissel, Satoru Terashima, I. Dillmann, I. G. Mukha, C. Scheidenberger, R. Kanungo, J. Kurcewicz, R. Janik, G. Guastalla, A. Estrade, Y.K. Tanaka, J. Vargas, D. Cortina-Gil, J. S. Winfield, T. D. Morris, Isao Tanihata, S. R. Stroberg, Helmut Weick, T. Suzuki, Peter Strmen, Junki Tanaka, F. Ameil, Wataru Horiuchi, R. Knöbel, C. Nociforo, Yassid Ayyad, and Geesaman, D. F.

Subjects
Nuclear and High Energy Physics, Proton, Nuclear Theory, Ab initio, Shell (structure), FOS: Physical sciences, 01 natural sciences, Nuclear Theory (nucl-th), Nuclear physics, Root mean square, 0103 physical sciences, ddc:530, Neutron, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Magic number (physics), Physics, Isotope, 010308 nuclear & particles physics, lcsh:QC1-999, Physics::Accelerator Physics, Halo, lcsh:Physics
Abstract

A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for $^{17-22}$N from charge changing cross section measurements around 900$A$ MeV at GSI. Neutron halo effects are signaled for $^{22}$N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at $N$ = 14 arising from the attractive proton-neutron tensor interaction, in good agreement with shell model calculations. $Ab$ $initio$, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon-nucleon and three-nucleon interaction reproduce well the data approaching the neutron drip-line isotopes but are challenged in explaining the complete isotopic trend of the radii., 18 pages, 3 figures

Published
2019
Full Text
View/download PDF

29. Improving Nuclear Data Input for r-Process Calculations Around A $$\sim $$ 80

Author

A. Tolosa-Delgado, J. Agramunt, D. S. Ahn, A. Algora, H. Baba, S. Bae, N. T. Brewer, C. Bruno, R. Caballero Folch, F. Calviño, P. J. Coleman-Smith, G. Cortés, T. Davinson, I. Dillmann, C. Domingo-Pardo, A. Estrade, N. Fukuda, S. Go, C. J. Griffin, R. Grzywacz, J. Ha, O. Hall, L. Harkness-Brennan, T. Isobe, D. Kahl, M. Karny, L. H. Khiem, G. G. Kiss, M. Kogimtzis, S. Kubono, M. Labiche, I. Lazarus, J. Lee, J. Liang, J. Liu, G. Lorusso, K. Matsui, K. Miernik, F. Montes, B. Moon, A. I. Morales, N. Nepal, S. Nishimura, R. D. Page, V. H. Phong, Z. Podolyak, V. F. E. Pucknell, B. C. Rasco, P. Regan, A. Riego, B. Rubio, K. P. Rykaczewski, Y. Saito, H. Sakurai, Y. Shimizu, J. Simpson, P.-A. Söderström, D. W. Stracener, T. Sumikama, H. Suzuki, J. L. Tain, M. Takechi, H. Takeda, A. Tarifeño-Saldivia, S. L. Thomas, P. J. Woods, X. X. Xu, and R. Yokoyama

Subjects
Nuclear physics, Physics, Abundance (ecology), Neutron emission, r-process, Nuclear data, Measure (mathematics)
Abstract

© 2019, Springer Nature Switzerland AG. We made an experiment to measure half-lives T1/2 and neutron emission probabilities Pxn of nuclei around mass 80, aiming to improve r-process abundance calculations around the first abundance peak with a new dedicated experimental setup at RIKEN. Details of the experiment and a few preliminary results are presented.

Published
2019
Full Text
View/download PDF

30. Stellar and thermal neutron capture cross section of $^9$Be

Author

Matthias Heil, Claudia Lederer-Woods, Martin Martschini, Peter Steier, Michael Wiescher, Robin Golser, Leonard Michlmayr, A. Mengoni, Alfred Priller, L. Coquard, W. Kutschera, F. Käppeler, Silke Merchel, I. Dillmann, Max Bichler, Anton Wallner, and Oliver Forstner

Subjects
Nuclear reaction, Physics, Astrophysics and Astronomy, 010308 nuclear & particles physics, Radiative capture, Thermal neutron capture, 7. Clean energy, 01 natural sciences, Nuclear physics, Cross section (physics), Work (electrical), Research council, 0103 physical sciences, Nuclear astrophysics, Nuclear Physics - Experiment, 010306 general physics
Abstract

The neutron capture cross section of Be9 for stellar energies was measured via the activation technique using the Karlsruhe Van de Graaff accelerator in combination with accelerator mass spectrometry at the Vienna Environmental Research Accelerator. To characterize the energy region of interest for astrophysical applications, activations were performed in a quasistellar neutron spectrum of kT=25 keV and for a spectrum at En=473±53 keV. Despite the very small cross section, the method used provided the required sensitivity for obtaining fairly accurate results of 10.4±0.6 and 8.4±1.0μb, respectively. With these data it was possible to constrain the cross section shape up to the first resonances at 622 and 812 keV, thus allowing for the determination of Maxwellian-averaged cross sections at thermal energies between kT=5 and 100 keV. In addition, we report a new experimental cross section value at thermal energy of σth=8.31±0.52 mb.

Published
2019

31. First measurement of isoscalar giant resonances in a stored-beam experiment

Author

I. Dillmann, V. K. Eremin, J. C. Zamora, M. Thürauf, Helmut Weick, M. Mahjour-Shafiei, Manfred Mutterer, Hans Geissel, S. Bagchi, Peter Egelhof, M. Kuilman, M. A. Najafi, D. Nagae, P. J. Woods, Tomohiro Uesaka, Catherine Rigollet, Yu. A. Litvinov, Takayuki Yamaguchi, Th. Kröll, Roman Gernhäuser, C. Nociforo, B. Streicher, Christoph Scheidenberger, Sergey Litvinov, M. Steck, C. Kozhuharov, F. Nolden, L. Stuhl, M.N. Harakeh, Danyal Winters, H. Kollmus, K. Yue, A.-L. Hartig, S. Ilieva, Santosh Roy, S. Bönig, M. Csatlós, Tatsuya Furuno, M. von Schmid, O. Kiselev, Nasser Kalantar-Nayestanaki, Thomas Aumann, Juzo Zenihiro, A. Krasznahorkay, U. Popp, J. S. Winfield, C. Dimopoulou, Research unit Nuclear & Hadron Physics, Theory of Condensed Matter, and Research unit Astroparticle Physics

Subjects
Nuclear reaction, Nuclear and High Energy Physics, Isoscalar, Nuclear Theory, 01 natural sciences, Nuclear physics, INELASTIC ALPHA-SCATTERING, ENERGY, 0103 physical sciences, EXCITATION, NI-58, PARTICLES, Neutron, ddc:530, 010306 general physics, Nuclear Experiment, Physics, NUCLEI, 010308 nuclear & particles physics, Momentum transfer, Resonance, lcsh:QC1-999, Inverse kinematics, Physics::Accelerator Physics, Isoscalar giant resonances, NEUTRON, Sum rule in quantum mechanics, DIPOLE RESONANCE, Atomic physics, Storage ring, Beam (structure), lcsh:Physics, MONOPOLE STRENGTH
Abstract

Physics letters / B 763, 16 - 19 (2016). doi:10.1016/j.physletb.2016.10.015, Published by North-Holland Publ., Amsterdam

Published
2016
Full Text
View/download PDF

32. First determination of β -delayed multiple neutron emission beyond A=100 through direct neutron measurement: The P2n value of Sb136

Author

W. Gelletly, I. Dillmann, Juha Äystö, E. Ganioglu, G. Cortes, Ari Jokinen, Jorge Agramunt, C. Domingo-Pardo, A. Algora, C. R. Nobs, Jani Hakala, Tommi Eronen, V. Guadilla, Jukka Koponen, P. Salvador-Castiñeira, F. Calviño, J. L. Tain, Sami Rinta-Antila, E. Mendoza, Ilkka Pohjalainen, R. Caballero-Folch, A. Montaner-Pizá, Heikki Penttilä, B. Rubio, Juuso Reinikainen, Dmitry Gorelov, Annika Voss, A. Tolosa-Delgado, Vasily Simutkin, Ariel Tarifeño-Saldivia, Iain Moore, Anu Kankainen, S. E. A. Orrigo, Veli Kolhinen, L. Canete, M. Marta, and A. Riego

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Neutron emission, Branching fraction, Nuclear Theory, Scintillator, 7. Clean energy, 01 natural sciences, Ion, Nuclear physics, Nucleosynthesis, 0103 physical sciences, Neutron, Nuclide, Nuclear Experiment, 010306 general physics
Abstract

Background: $\beta$-delayed multiple neutron emission has been observed for some nuclei with A$\leq$100, with $^{100}$Rb being the heaviest $\beta$2n emitter measured to date. So far, only 25 P$_{2n}$ values have been determined for the $\sim$300 nuclei that may decay in this way. Accordingly, it is of interest to measure P$_{2n}$ values for the other possible multiple neutron emitters throughout the chart of the nuclides. It is of particular interest to make such measurement for nuclei with A$>$100 to test the predictions of theoretical models and simulation tools for the decays of heavy nuclei in the region of very neutron-rich nuclei. In addition, the decay properties of these nuclei are fundamental for the understanding of astrophysical nucleosynthesis processes such as the $r$-process, and safety inputs for nuclear reactors. Purpose: To determine for the first time the two neutron branching ratio, P$_{2n}$ value, for $^{136}$Sb through a direct neutron measurement, and to provide precise P$_{1n}$ values for $^{136}$Sb and $^{136}$Te. Method: Pure beams were provided by the JYFLTRAP at the IGISOL facility of the University of Jyv\"askyl\"a, Finland. The purified ions were implanted into a moving tape at the end of the beam line. The detection setup consisted of a plastic scintillator placed right behind the implantation point, and the BELEN detector, based on neutron counters embedded in a polyethylene matrix. The analysis was based on the study of the $\beta$- and neutron- growth-and-decay curves and the $\beta$-one-neutron and $\beta$-two-neutron time correlations. Results: The P$_{2n}$ value of $^{136}$Sb was found to be 0.31(5)\% and the measured P$_{1n}$ values for $^{136}$Sb and $^{136}$Te were found to be 31.9(15)\% and 1.47(6)\%, respectively. The measured P$_{2n}$ value is a factor 20 smaller than predicted by the FRDM+QRPA model used for $r$-process calculations.

Published
2018
Full Text
View/download PDF

33. Structure of Be13 studied in proton knockout from B14

Author

Roy Crawford Lemmon, C. Wimmer, U. Datta Pramanik, K. Goebel, I. Syndikus, Nasser Kalantar-Nayestanaki, C. Wheldon, Enrique Nácher, Thomas Aumann, J. S. Winfield, Andreas Martin Heinz, N. Kurz, L. M. Fraile, Hans Geissel, Rene Reifarth, Mikhail V. Zhukov, J. Marganiec, E. Cravo, P. Velho, M. Heine, M. Caamaño, M. Roeder, O. Ershova, Alfredo Estrade, Martin Freer, Daniel Bemmerer, G. L. Wilson, P. J. Woods, S. Pietri, Z. Elekes, G. Ribeiro, Björn Jonson, J. M. Boillos, Joakim Cederkäll, J. Taylor, J. Hagdahl, Herbert A. Simon, Paloma Diaz Fernandez, T. Kroell, Andreas Wagner, Matthias Heil, R. Crespo, A. Ignatov, M. J. G. Borge, K. Riisager, Roman Gernhaeuser, K. Boretzky, A. Movsesyan, Andreas Zilges, Carlos A. Bertulani, A. Hufnagel, H. O. U. Fynbo, A. Kelic-Heil, V. Panin, T. Le Bleis, Christoph Langer, D. Cortina-Gil, L. Atar, E. Casarejos, R. Thies, Jorge Machado, Joachim Enders, Olof Tengblad, Marina Petri, Ralf Plag, J. Benlliure, Deniz Savran, D. M. Rossi, Marielle Chartier, C. Caesar, Y. Aksyutina, Simon Lindberg, Catherine Rigollet, L. V. Chulkov, Daniel Galaviz, M. Holl, O. Sorlin, C. Nociforo, Helmut Weick, Håkan T Johansson, H. Scheit, W. N. Catford, Ángel Perea, Vladimir Avdeichikov, I. Dillmann, Pavel Golubev, F. Farinon, Stefanos Paschalis, H. Alvarez-Pol, R. Kanungo, Marine Vandebrouck, Kai Zuber, M. Labiche, A. Henriques, S. Beceiro-Novo, Thomas Nilsson, F. Wamers, and Tanja Heftrich

Subjects
Physics, Nuclear reaction, Proton, 010308 nuclear & particles physics, Nuclear Theory, Gamma ray, Halo nucleus, 01 natural sciences, Resonance (particle physics), Nuclear physics, Excited state, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The neutron-unbound isotope Be-13 has been studied in several experiments using different reactions, different projectile energies, and different experimental setups. There is, however, no real consensus in the interpretation of the data, in particular concerning the structure of the low-lying excited states. Gathering new experimental information, which may reveal the Be-13 structure, is a challenge, particularly in light of its bridging role between Be-12, where the N = 8 neutron shell breaks down, and the Borromean halo nucleus Be-14. The purpose of the present study is to investigate the role of bound excited states in the reaction product Be-12 after proton knockout from B-14, by measuring coincidences between Be-12, neutrons, and gamma rays originating from de-excitation of states fed by neutron decay of Be-13. The Be-13 isotopes were produced in proton knockout from a 400 MeV/nucleon B-14 beam impinging on a CH2 target. The Be-12-n relative-energy spectrum d sigma/dE(fn) was obtained from coincidences between Be-12(g.s.) and a neutron, and also as threefold coincidences by adding gamma rays, from the de-excitation of excited states in Be-12. Neutron decay from the first 5/2(+) state in Be-13 to the 2(+) state in Be-12 at 2.11 MeV is confirmed. An energy independence of the proton-knockout mechanism is found from a comparison with data taken with a 35 MeV/nucleon B-14 beam. A low-lying p-wave resonance in Be-13(1/2(-)) is confirmed by comparing proton- and neutron-knockout data from B-14 and Be-14.

Published
2018
Full Text
View/download PDF

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

Author

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

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

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

Published
2018
Full Text
View/download PDF

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

Author

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

Subjects
Physics, Range (particle radiation), 010308 nuclear & particles physics, Eikonal equation, media_common.quotation_subject, Nuclear Theory, Ab initio, General Physics and Astronomy, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Asymmetry, Oxygen, Isotopes of oxygen, Nuclear physics, chemistry, Isospin, 0103 physical sciences, Particle, Nuclear Experiment, 010306 general physics, media_common
Abstract

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R3B/LAND setup with incident beam energies in the range of 300-450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type OA(p,2p)NA-1 have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

Published
2018
Full Text
View/download PDF

36. Halo structure of $^8$B determined from intermediate energy proton elastic scattering in inverse kinematics

Author

F. Farinon, S. Ilieva, Peter Egelhof, Alexei Khanzadeev, V. I. Yatsoura, J. Kurcewicz, An.A. Vorobyov, A. V. Dobrovolsky, I. Dillmann, C. Scheidenberger, Yu. A. Litvinov, M. Takechi, Alfredo Estrade, S. Tang, Y. Ke, G.A. Korolev, O.A. Kiselev, G. D. Alkhazov, G. E. Petrov, Herbert A. Simon, A. Prochazka, V. Volkov, Hans Geissel, L.O. Sergeev, Helmut Weick, X.C. Le, and A.G. Inglessi

Subjects
Nuclear and High Energy Physics, Proton, Nuclear Theory, FOS: Physical sciences, 01 natural sciences, Nuclear physics, Nuclear Theory (nucl-th), Recoil, 0103 physical sciences, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Elastic scattering, Physics, 010308 nuclear & particles physics, Scattering, Radius, lcsh:QC1-999, Ionization chamber, Halo, Glauber, lcsh:Physics
Abstract

Physics letters / B 780, 200 - 204 (2018). doi:10.1016/j.physletb.2018.03.013, Published by North-Holland Publ., Amsterdam

Published
2018
Full Text
View/download PDF

37. Precise measurement of the thermal and stellar Fe54(n,γ)Fe55 cross sections via accelerator mass spectrometry

Author

Marco Pignatari, Alberto Mengoni, Alfred Priller, Anton Wallner, Tamás Belgya, Amanda I. Karakas, Peter Steier, L. Coquard, C. Lederer, László Szentmiklósi, Rene Reifarth, F. Käppeler, Walter Kutschera, Max Bichler, Robin Golser, I. Dillmann, and K Buczak

Subjects
Nuclear reaction, Physics, 010308 nuclear & particles physics, 7. Clean energy, 01 natural sciences, Nuclear physics, Neutron capture, Stars, 13. Climate action, 0103 physical sciences, Thermal, Nuclear astrophysics, Asymptotic giant branch, Neutron, Atomic physics, 010306 general physics, Accelerator mass spectrometry
Abstract

Accelerator mass spectrometry (AMS) represents a complementary approach for precise measurements of neutron capture cross sections, e.g., for nuclear astrophysics. This technique, completely independent of previous experimental methods, was applied for the measurement of the $^{54}\mathrm{Fe}(n,\ensuremath{\gamma})^{55}\mathrm{Fe}$ reaction. Following a series of irradiations with neutrons from cold and thermal to keV energies, the produced long-lived $^{55}\mathrm{Fe}$ nuclei (${t}_{1/2}=2.744+\ensuremath{-}0.009)$ yr) were analyzed at the Vienna Environmental Research Accelerator. A reproducibility of about 1% could be achieved for the detection of $^{55}\mathrm{Fe}$, yielding cross-section uncertainties of less than 3%. Thus, this method produces new and precise data that can serve as anchor points for time-of-flight experiments. We report significantly improved neutron capture cross sections at thermal energy (${\ensuremath{\sigma}}_{\mathrm{th}}=2.30\ifmmode\pm\else\textpm\fi{}0.07$ b) as well as for a quasi-Maxwellian spectrum of $kT=25$ keV ($\ensuremath{\sigma}=30.3\ifmmode\pm\else\textpm\fi{}1.2$ mb) and for ${E}_{n}=481\ifmmode\pm\else\textpm\fi{}53$ keV ($\ensuremath{\sigma}=6.01\ifmmode\pm\else\textpm\fi{}0.23$ mb). The new experimental cross sections have been used to deduce improved Maxwellian-averaged cross sections in the temperature regime of the common $s$-process scenarios. The astrophysical impact is discussed by using stellar models for low-mass asymptotic giant branch stars.

Published
2017
Full Text
View/download PDF

38. β -decay half-lives and β -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N=126

Author

Yu. A. Litvinov, I. Dillmann, K. Steiger, Karl Smith, Hans Geissel, G. Cortes, Carlos Guerrero, E. Wilson, J. L. Tain, A. R. García, Roman Gernhäuser, E. Sokol, H. Schaffner, N. Kurz, A. Evdokimov, C. Domingo-Pardo, Helmut Weick, S. Pietri, J. Benlliure, M. Marta, D. Cano-Ott, L. Maier, R. Caballero-Folch, J. Agramunt, F. Calviño, J. Kurcewicz, F. Montes, A. Algora, M. Bowry, T. Martinez, A. Prochazka, A. V. Yeremin, C. Paradela, J. Marganiec, F. Ameil, M. B. Gómez-Hornillos, D. Galaviz, R. Knöbel, Zs. Podolyák, Stephen Rice, B. Rubio, C. Nociforo, Bao-Hua Sun, I. Kojouharov, D. Testov, Yassid Ayyad, C. Scheidenberger, R. Wood, D. R. Napoli, Philip Woods, Matthias Heil, Ivan Mukha, W. Gelletly, F. Farinon, A. Riego, M. Takechi, C. Hinke, A. Estrade, J. S. Winfield, Thomas Faestermann, and Thomas Davinson

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Branching fraction, 01 natural sciences, 7. Clean energy, Ion, 0103 physical sciences, Neutron detection, r-process, Neutron, Atomic physics, 010306 general physics, s-process, Delayed neutron
Abstract

Background: Previous measurements of Beta-delayed neutron emitters comprise around 230 nuclei, spanning from the 8He up to 150La. Apart from 210Tl, with a minuscule branching ratio of 0.07%, no other neutron emitter is measured yet beyond A = 150. Therefore new data are needed, particularly in the heavy mass region around N=126, in order to guide theoretical models and to understand the formation of the third r-process peak at A 195. Purpose: To measure both, Beta-decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb and Bi isotopes beyond N = 126. Method: Ions of interest are produced by fragmentation of a 238U beam, selected and identifed via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) is used to measure ion-implants and -decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) is used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time-correlations. The latter are analyzed with an analytical model and results for the half-lives and neutron-branching ratios are derived using the binned Maximum-Likelihood method. Results: Twenty new Beta-decay half-lives are reported for 204

Published
2017
Full Text
View/download PDF

39. Determination of the neutron-capture rate of C17 for r -process nucleosynthesis

Author

Håkan T Johansson, Pavel Golubev, Enrique Casarejos, T. Adachi, J. Van de Walle, Ethan Uberseder, G. L. Wilson, Y. Aksyutina, S. Beceiro-Novo, J. Enders, Ángel Perea, F. Farinon, C. Langer, R. Knöbel, J. Benlliure, O. Lepyoshkina, Marielle Chartier, A. Kelic-Heil, F. Wamers, N. I. Ashwood, A. Najafi, M. Barr, Kai Zuber, J. Alcantara, Tanja Heftrich, T. Le Bleis, A. Henriques, G. Ickert, J. S. Winfield, D. Cortina-Gil, Thomas Nilsson, G. Ribeiro, Hans Geissel, S. Pietri, Haik Simon, M. Freer, Anisur Rahaman, C. Caesar, Olof Tengblad, C. Nociforo, Stefanos Paschalis, O. Ershova, D. Rossi, Y. Togano, Stefan Typel, S. Chakraborty, A. Movsesyan, O. Sorlin, K. Boretzky, K. Riisager, P. Díaz Fernández, Andreas Zilges, A. Ignatov, Meng-Ru Wu, P. Velho, Vladimir Avdeichikov, Simon Lindberg, A. Prochazka, Catherine Rigollet, Mario Weigand, M. Caamaño, B. Streicher, J. Taylor, Z. Elekes, W. N. Catford, S. Terashima, K. Göbel, V. Panin, Bo Jakobsson, M. Heil, J. Hagdahl, Carlos A. Bertulani, M. V. Ricciardi, Björn Jonson, Philip Woods, M. Labiche, M. Freudenberger, L. M. Fraile, R. Plag, U. Datta Pramanik, S. Altstadt, Gabriel Martínez-Pinedo, R. Thies, Jorge Machado, T. Neff, Marina Petri, R. Crespo, H. Weick, M. Holl, J. Kurcewicz, Andreas Wagner, H. Scheit, H. Alvarez-Pol, R. Gernhäuser, H. O. U. Fynbo, Nasser Kalantar-Nayestanaki, G. Rastrepina, J. Sanchez del Rio, D. Galaviz, C. Wheldon, Thomas Aumann, Deniz Savran, N. Kurz, Andreas Martin Heinz, M. Röder, T. Kröll, V. Stoica, M. Mostazo, V. Volkov, M. Heine, Daniel Bemmerer, I. Dillmann, Joakim Cederkäll, D. Yakorev, Mikhail V. Zhukov, V. Maroussov, A. Estrade, J. Marganiec, Rene Reifarth, G. Burgunder, Roy Crawford Lemmon, C. Wimmer, Rituparna Kanungo, L. Chulkov, R. Krücken, D. Gonzalez Diaz, and María José García Borge

Subjects
Physics, education.field_of_study, 010308 nuclear & particles physics, Population, 7. Clean energy, 01 natural sciences, Spectral line, Nuclear physics, Neutron capture, Nucleosynthesis, Excited state, 0103 physical sciences, Coulomb, r-process, Atomic physics, Nuclear Experiment, 010306 general physics, education, Ground state
Abstract

With the R$^{3}$B-LAND setup at GSI we have measured exclusive relative-energy spectra of the Coulomb dissociation of $^{18}$C at a projectile energy around 425~AMeV on a lead target, which are needed to determine the radiative neutron-capture cross sections of $^{17}$C into the ground state of $^{18}$C. Those data have been used to constrain theoretical calculations for transitions populating excited states in $^{18}$C. This allowed to derive the astrophysical cross section $\sigma^{*}_{\mathrm{n}\gamma}$ accounting for the thermal population of $^{17}$C target states in astrophysical scenarios. The experimentally verified capture rate is significantly lower than those of previously obtained Hauser-Feshbach estimations at temperatures $T_{9}\leq{}1$~GK. Network simulations with updated neutron-capture rates and hydrodynamics according to the neutrino-driven wind model as well as the neutron-star merger scenario reveal no pronounced influence of neutron capture of $^{17}$C on the production of second- and third-peak elements in contrast to earlier sensitivity studies.

Published
2017
Full Text
View/download PDF

40. First Results from Griffin Including The Half-lives Of $^{128-130}$Cd

Author

Joshua N. Smith, J. L. Pore, M. R. Dunlop, Ruohong Li, R. Caballero-Folch, I. Dillmann, E. Macconnachie, Ryan Dunlop, Elizabeth Padilla-Rodal, C. Burbadge, A. B. Garnsworthy, A. D. MacLean, Corina Andreoiu, B. Olaizola, James Smallcombe, P. E. Garrett, H. Bidaman, G. Hackman, A. J. Radich, O. Paetkau, R. Krücken, A. Teigelhöfer, Joochun Park, G. C. Ball, E. McGee, A. Jungclaus, N. Bernier, S. V. Ilyushkin, P. Boubel, M. Moukaddam, V. Bildstein, D. Kisliuk, Samuel Tabor, F. H. Garcia, L. J. Evitts, T. Zidar, Jack Henderson, J. Lassen, S. Hallam, C. E. Svensson, J. Turko, P. Ruotsalainen, C. M. Petrache, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, Nuclear structure, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Semiconductor detector, Nuclear physics, Internal conversion, Nuclear astrophysics, Neutron, Nuclear Experiment
Abstract

Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) is a new high-efficiency $\gamma$-ray spectrometer for decay spectroscopy research with low-energy (20-60 keV) stopped radioactive beams from the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada. GRIFFIN is comprised of 16 HPGe clover detectors and hosts a suite of auxiliary detection systems for tagging $\beta$ particles, neutrons, and internal conversion electrons in coincidence with $\gamma$ rays. GRIFFIN is a powerful new tool for studying the nuclear structure of exotic short-lived isotopes far from stability, and for measuring weak $\gamma$-ray branches that are important in tests of fundamental symmetries and nuclear astrophysics. In this work, first results from the GRIFFIN physics program will be discussed, including a recent measurement of the half-lives of the neutron-rich $^{128-130}$Cd and $^{131}$In isotopes.

Published
2016
Full Text
View/download PDF

41. Proton Distribution Radii ofC12–19Illuminate Features of Neutron Halos

Author

S. Pietri, A. Estrade, Isao Tanihata, M. Takechi, J. Vargas, D. Cortina-Gil, Masaaki Kimura, Yu. A. Litvinov, A. Prochazka, J. Kurcewicz, C. Scheidenberger, Yassid Ayyad, F. Farinon, Petr Navrátil, G. Guastalla, Peter Strmen, I. G. Mukha, F. Ameil, M. Marta, Branislav Sitar, R. Janik, Y. Suzuki, C. Nociforo, Gustav R. Jansen, I. Dillmann, M. Mostazo, Junki Tanaka, J. S. Winfield, Satoru Terashima, Hooi Jin Ong, Hans Geissel, Wataru Horiuchi, J. Atkinson, Gaute Hagen, A. Evdokimov, Helmut Weick, R. Kanungo, and R. Knöbel

Subjects
Physics, Proton, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, Charge (physics), Radius, 01 natural sciences, Cross section (physics), chemistry, Ab initio quantum chemistry methods, 0103 physical sciences, Neutron, Halo, Atomic physics, Nuclear Experiment, 010306 general physics, Carbon
Abstract

We report proton radii of 12-19C densities derived from first accurate charge changing cross section measurements at 900A MeV with a carbon target. A thick neutron surface evolves from ~0.5 fm in 15C to ~1 fm in 19C. Also, the halo radius in 19C is found to be 6.4±0.7 fm as large as 11Li. Ab initio calculations based on chiral nucleon-nucleon and three-nucleon forces reproduce the radii well.

Published
2016
Full Text
View/download PDF

42. Parameter-free calculation of charge-changing cross sections at high energy

Author

S. Pietri, M. Takechi, Yu. A. Litvinov, I. G. Mukha, Alfredo Estrade, Hooi Jin Ong, Wataru Horiuchi, Branislav Sitar, J. Atkinson, Isao Tanihata, Christoph Scheidenberger, J. S. Winfield, I. Dillmann, J. Vargas, D. Cortina-Gil, R. Janik, Yasuyuki Suzuki, C. Nociforo, Peter Strmen, F. Farinon, Hans Geissel, R. Knoebel, Y. Ayyad, R. Kanungo, G. Guastalla, A. Evdokimov, Junki Tanaka, A. Prochazka, J. Kurcewicz, Helmut Weick, M. Marta, F. Ameil, M. Mostazo, and S. Terashima

Subjects
Physics, Proton, 010308 nuclear & particles physics, Eikonal equation, Charge (physics), 01 natural sciences, Effective nuclear charge, Nuclear physics, Cross section (physics), 0103 physical sciences, Neutron, 010306 general physics, Glauber, Energy (signal processing)
Abstract

Charge-changing cross sections at high energies are expected to provide useful information on nuclear charge radii. No reliable theory to calculate the cross section has yet been available. We develop a formula using Glauber and eikonal approximations and test its validity with recent new data on carbon isotopes measured at around $900A$ MeV. We first confirm that our theory reproduces the cross sections of $^{12,13,14}\mathrm{C}+^{12}\mathrm{C}$ consistently with the known charge radii. Next we show that the cross sections of $^{12\ensuremath{-}19}\mathrm{C}$ on a proton target are all well reproduced provided the role of neutrons is accounted for. We also discuss the energy dependence of the charge-changing cross sections.

Published
2016
Full Text
View/download PDF

43. Half-lives of neutron-richCd128–130

Author

D. Kisliuk, A. D. MacLean, T. Zidar, J. Turko, A. B. Garnsworthy, Elizabeth Padilla-Rodal, R. Dunlop, G. C. Ball, H. Bidaman, S. V. Ilyushkin, L. J. Evitts, James Smallcombe, A. J. Radich, J. Lassen, N. Bernier, A. Teigelhöfer, E. McGee, P. Ruotsalainen, Samuel Tabor, C. M. Petrache, Corina Andreoiu, J. L. Pore, E. Macconnachie, J. K. Smith, R. Krücken, G. Hackman, B. Olaizola, V. Bildstein, Ruohong Li, P. E. Garrett, C. Burbadge, I. Dillmann, Joochun Park, A. Jungclaus, M. Moukaddam, P. Boubel, R. Caballero-Folch, O. Paetkau, M. R. Dunlop, F. H. Garcia, C. E. Svensson, Jack Henderson, and S. Hallam

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, 01 natural sciences
Abstract

The $\ensuremath{\beta}$-decay half-lives of $^{128--130}\mathrm{Cd}$ have been measured with the newly commissioned GRIFFIN $\ensuremath{\gamma}$-ray spectrometer at the TRIUMF-ISAC facility. The time structures of the most intense $\ensuremath{\gamma}$ rays emitted following the $\ensuremath{\beta}$ decay were used to determine the half-lives of $^{128}\mathrm{Cd}$ and $^{130}\mathrm{Cd}$ to be ${T}_{1/2}=246.2\phantom{\rule{0.16em}{0ex}}(21)$ ms and ${T}_{1/2}=126\phantom{\rule{0.16em}{0ex}}(4)$ ms, respectively. The half-lives of the $3/{2}^{+}$ and $11/{2}^{\ensuremath{-}}$ states of $^{129}\mathrm{Cd}$ were measured to be ${T}_{1/2}(3/{2}^{+})=157\phantom{\rule{0.16em}{0ex}}(8)$ ms and ${T}_{1/2}(11/{2}^{\ensuremath{-}})=147\phantom{\rule{0.16em}{0ex}}(3)$ ms. The half-lives of the Cd isotopes around the $N=82$ shell closure are an important ingredient in astrophysical simulations to derive the magnitude of the second $r$-process abundance peak in the $A\ensuremath{\sim}130$ region. Our new results are compared with recent literature values and theoretical calculations.

Published
2016
Full Text
View/download PDF

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

Author

A. Estrade, G. Burgunder, Andreas Martin Heinz, Andreas Wagner, Enrique Casarejos, Roy Crawford Lemmon, C. Wimmer, Ethan Uberseder, M. Heine, T. Le Bleis, N. Kurz, H. O. U. Fynbo, Olof Tengblad, D. Cortina-Gil, V. Stoica, F. Farinon, L. Atar, D. Yakorev, Joachim Enders, Helmut Weick, Z. Elekes, Carlos A. Bertulani, J. Sanchez del Rio Saez, Håkan T Johansson, Daniel Bemmerer, M. Freudenberger, D. Galaviz, Mikhail V. Zhukov, Heiko Scheit, Herbert A. Simon, A. Ignatov, P. Diaz-Fernandez, Nasser Kalantar-Nayestanaki, C. Wheldon, Thomas Aumann, P. Velho, J. Van de Walle, K. Riisager, Pavel Golubev, U. Datta Pramanik, J. Taylor, J. Marganiec, G. L. Wilson, Ralf Plag, J. Benlliure, O. Lepyoshkina, Marielle Chartier, N. I. Ashwood, A. Movsesyan, M. Röder, Andreas Zilges, Yasuhiro Togano, P. J. Woods, Ronja Thies, S. Pietri, R. Kanungo, Kai Zuber, Najafi, M. Labiche, M. J. G. Borge, Thomas Nilsson, A. Prochazka, G. Ribeiro, Christoph Langer, Ángel Perea, Roman Gernhäuser, G. Ickert, T. Adachi, R. Crespo, K. Boretzky, J. S. Winfield, W. N. Catford, G. Rastrepina, H. Alvarez-Pol, Bo Jakobsson, M. Barr, L. M. Fraile, C. Nociforo, F. Wamers, Rahaman, M. V. Ricciardi, M. Mostazo Caro, Björn Jonson, T. Kröll, Y. Aksyutina, Vladimir Avdeichikov, R. Knöbel, Matthias Heil, C. Caesar, B. Streicher, Joakim Cederkäll, J. Hagdahl, J. Kurcewicz, Deniz Savran, M. Caamaño, V. Volkov, Satoru Terashima, M. Holl, O. Ershova, Kathrin Göbel, A. Henriques, Martin Freer, J. Alcantara, Jorge Machado, Marina Petri, D. M. Rossi, Tanja Heftrich, S. Chakraborty, Mario Weigand, Simon Lindberg, R. Krücken, D. Gonzalez Diaz, Catherine Rigollet, Hans Geissel, Rene Reifarth, O. Sorlin, L. V. Chulkov, I. Dillmann, Stefanos Paschalis, V. Panin, S. Altstadt, S. Beceiro, A. Kelic-Heil, Helmholtz zentrum für Schwerionenforschung GmbH (GSI), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Light nucleus, 010308 nuclear & particles physics, Thermonuclear reaction, Aucun, FOS: Physical sciences, chemistry.chemical_element, Detailed balance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Dissociation (chemistry), Ion, chemistry, 0103 physical sciences, Coulomb, Fluorine, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Nuclear Experiment, Excitation
Abstract

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

Published
2016
Full Text
View/download PDF

45. Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERN

Author

E. Mendoza, D. Cano Ott, C. Guerrero, E. Berthoumieux, U. Abbondanno, G. Aerts, F. Alvarez Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulos, L. Audouin, G. Badurek, J. Balibrea, P. Baumann, F. Becvar, F. Belloni, F. Calvino, M. Calviani, R. Capote, C. Carrapico, A. C. de, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Cortes, A. Couture, J. Cox, M. Dahlfors, S. David, I. Dillmann, R. Dolfini, C. Domingo Pardo, W. Dridi, I. Duran, C. Eleftheriadis, L. Ferrant, A. Ferrari, R. Ferreira Marques, L. Fitzpatrick, H. Frais Koelbl, K. Fujii, W. Furman, I. Goncalves, E. Gonzalez Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, F. Gunsing, B. Haas, R. Haight, M. Heil, A. Herrera Martinez, M. Igashira, S. Isaev, E. Jericha, F. Kaeppeler, Y. Kadi, D. Karadimos, D. Karamanis, V. Ketlerov, M. Kerveno, P. Koehler, V. Konovalov, E. Kossionides, M. Krticka, C. Lampoudis, H. Leeb, A. Lindote, S. L. Meo, I. Lopes, R. Lossito, M. Lozano, S. Lukic, J. Marganiec, L. Marques, S. Marrone, T. Martinez, MASSIMI, CRISTIAN, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neves, H. Oberhummer, S. O'Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulos, C. Paradela, N. Patronis, A. Pavlik, P. Pavlopoulos, L. Perrot, M. T. Pigni, R. Plag, A. Plompen, A. Plukis, A. Poch, J. Praena, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, C. Santos, L. Sarchiapone, I. Savvidis, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan Got, L. Tavora, R. Terlizzi, VANNINI, GIANNI, P. Vaz, A. Ventura, D. Villamarin, M. C. Vicente, V. Vlachoudis, R. Vlastou, F. Voss, S. Walter, H. Wendler, M. Wiescher, K. Wisshak, E. Mendoza, D. Cano-Ott, C. Guerrero, E. Berthoumieux, U. Abbondanno, G. Aert, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, L. Audouin, G. Badurek, J. Balibrea, P. Baumann, F. Becvar, F. Belloni, F. Calvino, M. Calviani, R. Capote, C. Carrapico, A. C. de, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Corte, A. Couture, J. Cox, M. Dahlfor, S. David, I. Dillmann, R. Dolfini, C. Domingo-Pardo, W. Dridi, I. Duran, C. Eleftheriadi, L. Ferrant, A. Ferrari, R. Ferreira-Marque, L. Fitzpatrick, H. Frais-Koelbl, K. Fujii, W. Furman, I. Goncalve, E. Gonzalez-Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, F. Gunsing, B. Haa, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, S. Isaev, E. Jericha, F. Kaeppeler, Y. Kadi, D. Karadimo, D. Karamani, V. Ketlerov, M. Kerveno, P. Koehler, V. Konovalov, E. Kossionide, M. Krticka, C. Lampoudi, H. Leeb, A. Lindote, S. L. Meo, I. Lope, R. Lossito, M. Lozano, S. Lukic, J. Marganiec, L. Marque, S. Marrone, T. Martinez, 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, C. Paradela, 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, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan-Got, L. Tavora, R. Terlizzi, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M. C. Vicente, V. Vlachoudi, R. Vlastou, F. Vo, S. Walter, H. Wendler, M. Wiescher, and K. Wisshak

Subjects
RADIATIVE NEUTRON CAPTURE, NEUTRON TIME OF FLIGHT
Abstract

Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am243(n,γ) cross section uncertainty. Method: The Am243(n,γ) cross section has been measured at the n-TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am243(n,γ) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am243(n,γ) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries. Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am243(n,γ) cross section uncertainty. Method: The Am243(n,γ) cross section has been measured at the n-TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am243(n,γ) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am243(n,γ) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries.

Published
2014

46. Ni-62(n,gamma) and Ni-63(n,gamma) cross sections measured at the n_TOF facility at CERN

Author

C. Lederer, E. Berthoumieux, N. Colonna, R. Dressler, C. Guerrero, F. Gunsing, F. Kaeppeler, N. Kivel, M. Pignatari, R. Reifarth, D. Schumann, A. Wallner, S. Altstadt, S. Andriamonje, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becares, F. Becvar, F. Belloni, B. Berthier, J. Billowes, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, G. Cortes, M. A. Cortes Giraldo, I. Dillmann, C. Domingo Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadis, M. Fernandez Ordonez, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez Hornillos, I. F. Goncalves, E. Gonzalez Romero, F. Gramegna, E. Griesmayer, P. Gurusamy, S. Harrisopulos, M. Heil, K. Ioannides, D. G. Jenkins, E. Jericha, Y. Kadi, D. Karadimos, G. Korschinek, M. Krticka, J. Kroll, C. Langer, E. Lebbos, H. Leeb, L. S. Leong, R. Losito, M. Lozano, A. Manousos, J. Marganiec, S. Marrone, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, M. Mirea, W. Mondalaers, C. Paradela, A. Pavlik, J. Perkowski, R. Plag, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, A. Riego, F. Roman, C. Rubbia, R. Sarmento, P. Schillebeeckx, S. Schmidt, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan Got, A. Tsinganis, L. Tlustos, S. Valenta, V. Variale, P. Vaz, A. Ventura, M. J. Vermeulen, R. Versaci, V. Vlachoudis, R. Vlastou, T. Ware, M. Weigand, C. Weiss, T. J. Wright, P. Zugec, MASSIMI, CRISTIAN, MINGRONE, FEDERICA, VANNINI, GIANNI, C. Lederer, C. Massimi, E. Berthoumieux, N. Colonna, R. Dressler, C. Guerrero, F. Gunsing, F. Kaeppeler, N. Kivel, M. Pignatari, R. Reifarth, D. Schumann, A. Wallner, S. Altstadt, S. Andriamonje, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, B. Berthier, J. Billowe, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, G. Corte, M. A. Cortes-Giraldo, I. Dillmann, C. Domingo-Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadi, M. Fernandez-Ordonez, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, F. Gramegna, E. Griesmayer, P. Gurusamy, S. Harrisopulo, M. Heil, K. Ioannide, D. G. Jenkin, E. Jericha, Y. Kadi, D. Karadimo, G. Korschinek, M. Krticka, J. Kroll, C. Langer, E. Lebbo, H. Leeb, L. S. Leong, R. Losito, M. Lozano, A. Manouso, J. Marganiec, S. Marrone, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Pavlik, J. Perkowski, R. Plag, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, A. Riego, F. Roman, C. Rubbia, R. Sarmento, P. Schillebeeckx, S. Schmidt, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, L. Tlusto, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, M. J. Vermeulen, R. Versaci, V. Vlachoudi, R. Vlastou, T. Ware, M. Weigand, C. Wei, T. J. Wright, and P. Zugec

Subjects
Astrophysics::High Energy Astrophysical Phenomena, CERN - n_TOF, radiative capture cross section, S PROCESS, Nuclear Experiment
Abstract

The cross section of the Ni-62(n,gamma) reaction was measured with the time-of-flight technique at the neutron time-of-flight facility n_TOF at CERN. Capture kernels of 42 resonances were analyzed up to 200 keV neutron energy and Maxwellian averaged cross sections (MACS) from kT = 5-100 keV were calculated. With a total uncertainty of 4.5%, the stellar cross section is in excellent agreement with the the KADoNiS compilation at kT = 30 keV, while being systematically lower up to a factor of 1.6 at higher stellar temperatures. The cross section of the Ni-63(n,gamma) reaction was measured for the first time at n_TOF. We determined unresolved cross sections from 10 to 270 keV with a systematic uncertainty of 17%. These results provide fundamental constraints on s-process production of heavier species, especially the production of Cu in massive stars, which serve as the dominant source of Cu in the solar system.

Published
2014

47. Accelerator mass spectrometry measurements of theC13(n,γ)C14andN14(n,p)C14cross sections

Author

F. Käppeler, K Buczak, Maria Lugaro, Amanda I. Karakas, Anton Wallner, G. Schätzel, C. Lederer, Max Bichler, I. Dillmann, K. Mair, Peter Steier, H. P. Trautvetter, and Alberto Mengoni

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Nuclear data, 7. Clean energy, 01 natural sciences, Nuclear physics, Neutron capture, Stars, Nucleosynthesis, 0103 physical sciences, Neutron, Production (computer science), Nuclear Experiment, s-process, 010303 astronomy & astrophysics, Accelerator mass spectrometry
Abstract

Many heavy elements in the universe are produced by slow neutron capture (the $s$ process) in stars, and one needs detailed knowledge of both neutron production and capture to understand the physics. This paper reports new measurements of neutron capture on ${}^{13}$C and ${}^{14}$N that both lead to ${}^{14}$C and which act as neutron ''poisons'' that starve the $s$ process of neutrons, thus hampering the formation of the heavier elements. The authors use different accelerators, one to perform the capture reaction and one to measure, via accelerator mass spectrometry, the number of produced ${}^{14}$C nuclei. These data reduce the uncertainty in the predicted stellar neutron densities and the resulting heavy-element yields from the $s$ process.

Published
2016
Full Text
View/download PDF

48. First Measurement of Several β -Delayed Neutron Emitting Isotopes Beyond N = 126

Author

R. Caballero-Folch, C. Domingo-Pardo, J. Agramunt, A. Algora, F. Ameil, A. Arcones, Y. Ayyad, J. Benlliure, I. N. Borzov, M. Bowry, F. Calviño, D. Cano-Ott, G. Cortés, T. Davinson, I. Dillmann, A. Estrade, A. Evdokimov, T. Faestermann, F. Farinon, D. Galaviz, A. R. García, H. Geissel, W. Gelletly, R. Gernhäuser, M. B. Gómez-Hornillos, C. Guerrero, M. Heil, C. Hinke, R. Knöbel, I. Kojou

Published
2016
Full Text
View/download PDF

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

Author

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

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

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

Published
2016

50. AMS Applications in Nuclear Astrophysics: New Results for 13C(n,γ) 14C and 14N(n,p) 14C

Author

I. Dillmann, Ulrich Ott, Michael Paul, G. Schätzel, H.P. Trautvetter, K Buczak, Peter Steier, F. Käppeler, Alberto Mengoni, Gunther Korschinek, Anton Wallner, C. Lederer, and Jenny Feige

Subjects
Physics, Nuclear physics, Nuclear reaction, Radionuclide, Space and Planetary Science, Nucleosynthesis, Nuclear astrophysics, Astronomy and Astrophysics, Neutron, Nuclide, Astrophysics, Accelerator mass spectrometry, Neutron activation
Abstract

The technique of accelerator mass spectrometry (AMS) offers a complementary tool for studying long-lived radionuclides in nuclear astrophysics: (1) as a tool for investigating nucleosynthesis in the laboratory; and (2) via a direct search of live long-lived radionuclides in terrestrial archives as signatures of recent nearby supernova-events. A key ingredient to our understanding of nucleosynthesis is accurate cross-section data. AMS was applied for measurements of the neutron-induced cross sections 13C(n,γ) and 14N(n,p), both leading to the long-lived radionuclide 14C. Solid samples were irradiated at Karlsruhe Institute of Technology with neutrons closely resembling a Maxwell–Boltzmann distribution for kT = 25 keV, and with neutrons of energies between 123 and 178 keV. After neutron activation the amount of 14C nuclides in the samples was measured by AMS at the VERA (Vienna Environmental Research Accelerator) facility. Both reactions, 13C(n,γ)14C and 14N(n,p)14C, act as neutron poisons in s-process nucleosynthesis. However, previous experimental data are discordant. The new data for both reactions tend to be slightly lower than previous measurements for the 25 keV Maxwell–Boltzmann energy distribution. For the higher neutron energies no previous data did exist for 13C(n,γ), but model calculations indicated a strong resonance structure between 100 and 300 keV which is confirmed by our results. Very limited information is available for 14N(n,p) at these energies. Our new data at 123 and 178 keV suggest lower cross sections than expected from previous experiments and data evaluations.

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results