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152 results on '"Th. Kröll"'

1. New evidence for alpha clustering structure in the ground state band of 212Po

Author

Ma. von Tresckow, M. Rudigier, T.M. Shneidman, Th. Kröll, M. Boromiza, C. Clisu, C. Costache, D. Filipescu, N.M. Florea, I. Gheorghe, K. Gladnishki, A. Ionescu, D. Kocheva, R. Lică, N. Mărginean, R. Mărginean, K.R. Mashtakov, C. Mihai, R.E. Mihai, A. Negret, C.R. Nita, A. Olacel, A. Oprea, S. Pascu, G. Rainovski, T. Sava, M. Scheck, P. Spagnoletti, C. Sotty, L. Stan, I. Stiru, S. Toma, A. Turturică, and S. Ujeniuc

Subjects
212Po, Lifetime measurement, α-clustering in nuclear, Centroid shift method, Physics, QC1-999
Abstract

Half-lives of the low-lying yrast states of 212Po have been measured using the delayed coincidence fast-timing method. We report on the first measurement of the 41+ half-life, as well as a new measurement of the 61+ half-life with improved accuracy compared to previous studies. The extracted lifetime of the 41+ and 61+ state have been determined to be 100(14) ps and 1.66(28) ns respectively. With these measurements, precise values are now available for the reduced transition strengths B(E2) of all ground state band levels in 212Po up to the first 8+ state, in particular B(E2; 41+→21+) = 9.4(13) W.u. and B(E2;61+→41+) = 8.7(15) W.u. Comparison of the new available data with an α-clustering model calculation provides evidence that the inclusion of the α-cluster degree of freedom significantly improves agreement with experimental data compared to earlier shell model calculations.

Published
2021
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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
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3. 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
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4. Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions

Author

J. Diriken, N. Patronis, A.N. Andreyev, S. Antalic, V. Bildstein, A. Blazhev, I.G. Darby, H. De Witte, J. Eberth, J. Elseviers, V.N. Fedosseev, F. Flavigny, Ch. Fransen, G. Georgiev, R. Gernhauser, H. Hess, M. Huyse, J. Jolie, Th. Kröll, R. Krücken, R. Lutter, B.A. Marsh, T. Mertzimekis, D. Muecher, F. Nowacki, R. Orlandi, A. Pakou, R. Raabe, G. Randisi, P. Reiter, T. Roger, M. Seidlitz, M. Seliverstov, K. Sieja, C. Sotty, H. Tornqvist, J. Van De Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, and K. Wimmer

Subjects
Nuclear physics, One-nucleon transfer reactions, RIBs, Nuclear structure, Physics, QC1-999
Abstract

The νg9/2,d5/2,s1/2 orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below 68Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby 67Ni nucleus, by performing a (d,p)-experiment in inverse kinematics employing a post-accelerated radioactive ion beam (RIB) at the REX-ISOLDE facility. The experiment was performed at an energy of 2.95 MeV/u using a combination of the T-REX particle detectors, the Miniball γ-detection array and a newly-developed delayed-correlation technique as to investigate μs-isomers. Angular distributions of the ground state and multiple excited states in 67Ni were obtained and compared with DWBA cross-section calculations, leading to the identification of positive-parity states with substantial νg9/2 (1007 keV) and νd5/2 (2207 keV and 3277 keV) single-particle strengths up to an excitation energy of 5.8 MeV. 50% of the νd5/2 single-particle strength relative to the νg9/2-orbital is concentrated in and shared between the first two observed 5/2+ levels. A comparison with extended Shell Model calculations and equivalent (3He, d) studies in the region around 9040Zr50 highlights similarities for the strength of the negative-parity pf and positive-parity g9/2 state, but differences are observed for the d5/2 single-particle strength.

Published
2014
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5. Erratum to 'Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions' [Phys. Lett. B 736 (2014) 533–538]

Author

J. Diriken, N. Patronis, A.N. Andreyev, S. Antalic, V. Bildstein, A. Blazhev, I.G. Darby, H. De Witte, J. Eberth, J. Elseviers, V.N. Fedosseev, F. Flavigny, Ch. Fransen, G. Georgiev, R. Gernhauser, H. Hess, M. Huyse, J. Jolie, Th. Kröll, R. Krücken, R. Lutter, B.A. Marsh, T. Mertzimekis, D. Muecher, F. Nowacki, R. Orlandi, A. Pakou, R. Raabe, G. Randisi, P. Reiter, T. Roger, M. Seidlitz, M. Seliverstov, K. Sieja, C. Sotty, H. Tornqvist, J. Van De Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, and K. Wimmer

Subjects
Physics, QC1-999
Published
2015
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7. Neutron capture cross sections of light neutron-rich nuclei relevant for r-process nucleosynthesis

Author

M. Heine, Th. Kröll, S. Chakraborty, Rene Reifarth, Stefan Typel, P. Díaz Fernández, D. M. Rossi, Ushasi Datta, Marielle Chartier, Ralf Plag, J. Marganiec, A. Bhattacharyya, Catherine Rigollet, Christoph Langer, V. Panin, M. V. Ricciardi, C. Nociforo, P. Das, R. Krücken, Yvonne Leifels, S. Beceiro-Novo, Herbert A. Simon, Anisur Rahaman, C. Caesar, H. Geissel, J. S. Winfield, Andreas Wagner, Nasser Kalantar-Nayestanaki, Björn Jonson, H. Emling, T. Le Bleis, W. N. Catford, Thomas Aumann, D. Cortina-Gil, Stefanos Paschalis, Yasuhiro Togano, G. Münzenberg, Yutaka Utsuno, C. Scheidenberger, Helmut Weick, Håkan T Johansson, H. Scheit, D. González-Díaz, J. Kurcewicz, K. Boretzky, G. De. Angelis, B. V. Carlson, Thomas Nilsson, F. Wamers, Nuclear Energy, Institut Pluridisciplinaire Hubert Curien (IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Neutron capture, 010308 nuclear & particles physics, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, r-process nucleosynthesis, Dissociation (chemistry), Nuclear physics, Reaction rate, Nucleosynthesis, neutron-rich nuclei, 0103 physical sciences, Neutron cross section, r-process, Neutron, Hauser-Feshbach, 010306 general physics, Ground state, Nuclear Experiment
Abstract

International audience; The measurements of neutron capture cross sections of neutron-rich nuclei are challenging but essential for understanding nucleosynthesis and stellar evolution processes in the explosive burning scenario. In the quest of r-process abundances, according to the neutrino-driven-wind model, light neutron-rich unstable nuclei may play a significant role as seed nuclei that influence the abundance pattern. Hence, experimental data for neutron capture cross sections of neutron-rich nuclei are needed. Coulomb dissociation of radioactive ion beams at intermediate energy is a powerful indirect method for inferring capture cross section. As a test case for validation of the indirect method, the neutron capture cross section (n, γ) for C14 was inferred from the Coulomb dissociation of C15 at intermediate energy (600A MeV). A comparison between different theoretical approaches and experimental results for the reaction is discussed. We report for the first time experimental reaction cross sections of Na28(n,γ)Na29, Na29(n,γ)Na30, Mg32(n,γ)Mg33, and Al34(n,γ)Al35. The reaction cross sections were inferred indirectly through Coulomb dissociation of Na29,30, Mg33, and Al35 at incident projectile energies around 400–430 A MeV using the FRS-LAND setup at GSI, Darmstadt. The neutron capture cross sections were obtained from the photoabsorption cross sections with the aid of the detailed balance theorem. The reaction rates for the neutron-rich Na, Mg, Al nuclei at typical r-process temperatures were obtained from the measured (n,γ) capture cross sections. The measured neutron capture reaction rates of the neutron-rich nuclei, Na28, Na29, and Al34 are significantly lower than those predicted by the Hauser-Feshbach decay model. A similar trend was observed earlier for C17 and N19 but in the case of C14(n,γ)C15 the trend is opposite. The situation is more complicated when the ground state has a multi-particle-hole configuration. For Mg32, the measured cross section is about 40–90% higher than the Hauser-Feshbach prediction.

Published
2021

8. Microscopic structure of the one-phonon 2+ states of Po208

Author

G. De Gregorio, K. A. Gladnishki, C. Müller-Gatermann, Marcus Scheck, K. E. Ide, Norbert Pietralla, H. Naïdja, K. Stoychev, S. S. Dimitrova, V. Werner, R. Kern, A. Dewald, C. Henrich, A. Gargano, Th. Kröll, M. Stoyanova, D. Kalaydjieva, P. R. John, I. Homm, D. Kocheva, J. Jolie, A. Blazhev, V. Karayonchev, M. Djongolov, P. Spagnoletti, J. Kleemann, A. Esmaylzadeh, A. Goldkuhle, G. Rainovski, A. Yaneva, M. Beckers, and C. Fransen

Subjects
Physics, Matrix (mathematics), symbols.namesake, Recoil, Isovector, Phonon, Nuclear Theory, Quadrupole, symbols, Spectroscopy, Valence electron, Doppler effect, Molecular physics
Abstract

The lifetimes of the 2 1 + and 4 1 + states of Po 208 were measured in the α -transfer reaction Pb 204 ( C 12 , Be 8 ) Po 208 by γ -ray spectroscopy utilizing the recoil distance Doppler shift method. The newly extracted transition strengths alongside ones of the decay of the 2 2 + state were compared to the results of large-scale shell-model calculations using an effective interaction derived from the realistic CD-Bonn nucleon-nucleon potential. The comparison indicates the importance of the quadrupole isovector excitations in the valence shell for a fine tuning of the two-body matrix elements of the shell-model interaction.

Published
2021

9. Spectroscopy and lifetime measurements in Te134,136,138 isotopes and implications for the nuclear structure beyond N=82

Author

D. Verney, D. Ralet, J. Wiederhold, S. Bottoni, L. Matthieu, B. Fornal, A. Blazhev, P. H. Regan, C. Schmitt, R.L. Canavan, K. Rezynkina, D. Reygadas Tello, A. Lopez-Martens, K. Hauschild, B. Wasilewska, I. Matea, A. Korgul, C. Henrich, J. Jolie, V. Guadilla, M. Lebois, M. Babo, Th. Kröll, L. M. Fraile, J. Benito, G. Benzoni, T. Kurtukian-Nieto, L. Qi, Stephan Oberstedt, C. Porzio, M. Bunce, N. Warr, R. B. Gerst, P. A. Söderström, Y. Popovitch, W. Paulsen, F. Ibrahim, Ł. W. Iskra, G. Häfner, J. N. Wilson, S. Jazwari, M. S. Yavahchova, R. Chakma, C. Delafosse, A. Boso, R. Lozeva, N. Jovančević, V. Sanchez, H. Naïdja, M. Rudigier, P. Adsley, L. Le-meur, N. Cieplicka-Oryńczak, I. Homm, E. Adamska, G. Tocabens, K. Belvedere, D. Gjestvang, D. Thisse, M. L. Cortés, P. Koseoglou, P. Davies, V. Vedia, J. Nemer, M. Piersa, Muriel Fallot, C. Sürder, K. Miernik, S. M. Collins, S. Ziliani, D. Etasse, Fabio Zeiser, and J. Ljungvall

Subjects
Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, Fission, Nuclear structure, Context (language use), 7. Clean energy, 01 natural sciences, Excited state, 0103 physical sciences, Neutron source, Atomic physics, 010306 general physics, Spectroscopy
Abstract

We report on spectroscopic information and lifetime measurements of even-even neutron-rich Te isotopes. Excited states were populated in fast-neutron induced fission of U238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid ν-ball spectrometer. We provide first results on lifetimes of the 61+ state in Te136 and the (61+), (41+), and (21+) states in Te138 and discuss the results in the context of large-scale shell-model calculations. The level schemes of Te136 and Te138 are revised in terms of lifetimes of their 21+,41+ states and updated information on the (42+) state in Te136 is presented. In addition, previously reported data on spectroscopy and lifetimes in Te134 are reexamined. This work provides new insights into the evolution of collectivity for Te isotopes with N=82,84,86.

Published
2021

10. First lifetime investigations of $N>82$ iodine isotopes: The quest for collectivity

Author

A. Korgul, J. Wiederhold, Th. Kröll, S. Leoni, P. Adsley, Muriel Fallot, M. Babo, J. Benito, G. Benzoni, V. Vedia, K. Miernik, L. Qi, J. Nemer, V. Guadilla, C. Sürder, S. Bottoni, D. Verney, S. Jazwari, N. Warr, A. Boso, K. Rezynkina, D. Ralet, J. Ljungvall, F. Ibrahim, L. M. Fraile, T. Kurtukian-Nieto, M. Lebois, Fabio Zeiser, R. Chakma, A. Blazhev, P. H. Regan, R. Lozeva, C. Schmitt, L. Matthieu, R.L. Canavan, M. Piersa-Siłkowska, A. Algora, N. Jovančević, J. N. Wilson, Y. Popovitch, N. Cieplicka-Oryńczak, W. Paulsen, E. Adamska, G. Tocabens, P. Davies, K. Belvedere, D. Gjestvang, S. M. Collins, S. Ziliani, D. Etasse, M. Bunce, C. Henrich, R. B. Gerst, A. Lopez-Martens, M. Rudigier, Ł. W. Iskra, G. Häfner, B. Wasilewska, Stephan Oberstedt, C. Porzio, P. A. Söderström, C. Delafosse, V. Sánchez-Tembleque, L. Le-meur, H. Naïdja, M. S. Yavahchova, P. Koseoglou, I. Homm, D. Thisse, M. L. Cortés, D. Reygadas Tello, K. Hauschild, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), 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), Institut Laue-Langevin (ILL), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre 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), ILL, and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, chemistry.chemical_element, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Iodine, 01 natural sciences, chemistry, Excited state, 0103 physical sciences, Neutron source, Física nuclear, Atomic physics, 010306 general physics
Abstract

International audience; We report on spectroscopic information and lifetime measurements in the neutron-rich I135,137,139 isotopes. This is the first lifetime data on iodine isotopes beyond N=82. Excited states were populated in fast neutron-induced fission of U238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid ν-ball spectrometer. The level schemes of the I135,137,139 isotopes are revised in terms of excited states with up to maximum spin-parity of (33/2+), populated for the first time in fast neutron-induced fission. We provide first results on the lifetimes of the (9/21+) and (13/21+) states in I137 and I139, and the (17/21+) state in I137. In addition, we give upper lifetime limits for the (11/21+) states in I135−139, the (15/21+) state in I137, the (17/21+) state in I139, and reexamine the (29/21+) state in I137. The isomeric data in I135 are reinvestigated, such as the previously known (15/21+) and (23/21−) isomers with T1/2 of 1.64(14) and 4.6(7) ns, respectively, as obtained in this work. The new spectroscopic information is compared to that from spontaneous or thermal-neutron induced fission and discussed in the context of large scale shell-model (LSSM) calculations for the region beyond Sn132, indicating the behavior of collectivity for the three valence-proton iodine chain with N=82,84,86.

Published
2021

11. Evolution of single-particle structure near the $N=20$ island of inversion

Author

E. F. Baader, Ismael Martel, M. Labiche, R. D. Page, P. A. Butler, M. J. G. Borge, I.H. Lazarus, T. L. Tang, D. G. McNeel, Liam Gaffney, R. S. Lubna, P. T. MacGregor, O. Poleshchuk, B. P. Kay, B. D. Cropper, Calem Hoffman, W. N. Catford, Riccardo Raabe, G. de Angelis, Jiecheng Yang, D. K. Sharp, Th. Kröll, S. J. Freeman, Joonas Konki, F. Recchia, Science and Technology Facilities Council (UK), Department of Energy (US), European Commission, Research Foundation - Flanders, Ministerio de Ciencia e Innovación (España), Argonne National Laboratory (US), and European Organization for Nuclear Research

Subjects
Physics, Science & Technology, SPECTROSCOPY, NUCLEI, Spectrometer, Solenoidal vector field, 010308 nuclear & particles physics, Island of inversion, Structure (category theory), Shell (structure), 01 natural sciences, 7. Clean energy, Physics, Nuclear, Atomic orbital, Physical Sciences, 0103 physical sciences, Finite geometry, Particle, Nuclear Physics - Experiment, Atomic physics, 010306 general physics, DECAY
Abstract

7 pags., 5 figs., 2 tabs., The single-particle properties of Mg29 have been investigated via a measurement of the Mg28(d,p)Mg29 reaction, in inverse kinematics, using the ISOLDE Solenoidal Spectrometer. The negative-parity intruder states from the fp shell have been identified and used to benchmark modern shell-model calculations. The systematic data on the single-particle centroids along the N=17 isotones show good agreement with shell-model predictions in describing the observed trends from stability toward O25. However, there is also evidence that the effect of the finite geometry of the nuclear potential is playing a role on the behavior of the p orbitals near the particle-emission threshold., This work wassupported by the U.K. Science and Technology Facilities Council [Grants No. ST/P004598/1, No. ST/N002563/1, No. ST/M00161X/1 (Liverpool), No. ST/P004423/1 (Manchester), No. ST/P005314/1 (Surrey), the ISOL-SRS Grant (Daresbury), No. ST/R004056/1 (Ernest Rutherford Fellowship - Gaffney), and No. ST/T004797/1 (Ernest Rutherford Fellowship - Sharp)], the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contracts No. DE-AC02-06CH11357 (ANL) and No. DE-SC-0014552 (UConn), the European Union’s Horizon 2020 Framework research and innovation program under Grant Agreement No. 654002 (ENSAR2), the Marie Skłodowska-Curie Grant Agreement No. 665779, the Research Foundation Flanders (FWO, Belgium), the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 617156, and the Spanish Ministry of Science and Innovation under Grants No. PGC2018-095640- B-I00“ELEGANT” and No. PID2019-104390GB-I00. This research used targets provided by the Center for Accelerator Target Science at Argonne National Laboratory. The FSU shell-model calculations were performed using the computational facility of the nuclear physics theory group, Florida State University, supported by grants from the U.S. Department of Energy, Office of Science (DE-SC-0009883 (FSU).

Published
2021

12. Quadrupole deformation of Xe-130 measured in a Coulomb-excitation experiment

Author

J. Samorajczyk-Pyśk, E. Giannopoulos, R.L. Canavan, H. De Witte, L. Morrison, P. J. Napiorkowski, Ch. Fransen, A. Boukhari, M. Zielińska, Richard Catherall, Zs. Podolyák, J.P. Ramos, F. Wenander, D. T. Doherty, H. Hess, Liam Gaffney, D. Rosiak, S. Thiel, J. Snäll, L. Próchniak, P. Reiter, M. Brunet, P. Spagnoletti, M. Rudigier, J. Srebrny, M. Siciliano, Y. Martinez Palenzuela, J. G. Cubiss, K. Hadyńska-Klȩk, G. G. O'Neill, Janne Pakarinen, N. Lalović, B. A. Marsh, L. Kaya, Th. Kröll, Sebastian Rothe, Jose Rodriguez, S.J. Colosimo, T. Berry, Radostina Zidarova, N. Warr, Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Helsinki Institute of Physics

Subjects
Diagonal, Semiclassical physics, BEAM, Coulomb excitation, hiukkasfysiikka, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 114 Physical sciences, 01 natural sciences, sähkömagneettiset ilmiöt, nukleonit, symbols.namesake, Matrix (mathematics), NUCLEAR-DATA SHEETS, 0103 physical sciences, Phenomenological model, Nuclear Physics - Experiment, ddc:530, 010306 general physics, Physics, Science & Technology, 010308 nuclear & particles physics, nucleon distribution, Bohr model, Physics, Nuclear, electromagnetic transitions, STATES, SHAPES, Quadrupole, Physical Sciences, symbols, Atomic physics, ydinfysiikka, Hamiltonian (quantum mechanics)
Abstract

Physical review / C 102(5), 054304 (2020). doi:10.1103/PhysRevC.102.054304, Published by Inst., Woodbury, NY

Published
2020

13. Experimental evidence for low-lying quadrupole isovector excitation of $$^{208}$$Po

Author

P. R. John, J. Jolie, P. Spagnoletti, K. A. Gladnishki, G. Rainovski, C. Fransen, A. Dewald, Th. Kröll, D. Kalaydjieva, A. Blazhev, Marcus Scheck, A. Yaneva, K. E. Ide, R. Kern, C. Henrich, J. Kleemann, D. Kocheva, I. Homm, Norbert Pietralla, V. Werner, M. Stoyanova, C. Müller-Gatermann, V. Karayonchev, and M. Djongolov

Subjects
Physics, Nuclear and High Energy Physics, Isovector, 010308 nuclear & particles physics, 0103 physical sciences, Hadron, Quadrupole, Nuclear fusion, State (functional analysis), Atomic physics, 010306 general physics, 01 natural sciences, Excitation
Abstract

We present the results from an experiment dedicated to measure the lifetime of the $$2^+_2$$ state, candidate for the one-phonon mixed-symmetry state, of $$^{208}$$ Po. This nucleus was studied in the $$\alpha $$ -transfer reaction $$^{204}$$ Pb( $$^{12}$$ C, $$^{8}$$ Be) $$^{208}$$ Po and the lifetime of the $$2^+_2$$ state was determined by utilizing the Doppler-shift attenuation method. The experimental data show that the $$2^+_2$$ state decays with a sizable M1 transition to the $$2^+_1$$ state revealing its isovector nature.

Published
2020

14. Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive Ra222 and Ra228 Beams

Author

J. Sinclair, Joonas Konki, M. Lozano, A. Illana, D. T. Joss, S. Vinals, Robert Page, Th. Kröll, A. Goldkuhle, K. Wrzosek-Lipska, D. Rosiak, Liam Gaffney, M. Zielińska, V. Virtanen, P. Van Duppen, P. E. Garrett, K. Abrahams, H. De Witte, T.M. Shneidman, J. Ojala, P. Reiter, David O'Donnell, Mike Bowry, P. Spagnoletti, N. Warr, M. Seidlitz, M. Stryjczyk, B. Siebeck, P. A. Butler, Marcus Scheck, Karl Johnston, M. Komorowska, J. F. Smith, L. G. Pedersen, J. M. Keatings, Joakim Cederkäll, G. de Angelis, C. Henrich, B. S. Nara Singh, N. A. Kelly, Sebastian Rothe, C. Raison, and Jose Rodriguez

Subjects
Physics, Isotope, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, Coulomb excitation, 01 natural sciences, Radium, Matrix (mathematics), chemistry, Excited state, 0103 physical sciences, Atomic nucleus, Coulomb, Physics::Accelerator Physics, Physics::Atomic Physics, Atomic physics, Deformation (engineering), Nuclear Experiment, 010306 general physics
Abstract

There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.

Published
2020

15. Addendum: The observation of vibrating pear-shapes in radon nuclei

Author

T.M. Shneidman, P. E. Garrett, Jose Rodriguez, H. De Witte, David O'Donnell, M. Stryjczyk, D. Rosiak, Timothy Chupp, Th. Kröll, P. Reiter, B. Siebeck, J. Sinclair, P. Spagnoletti, J. F. Smith, V. Virtanen, Karl Johnston, N. A. Kelly, J. M. Keatings, Marcus Scheck, Liam Gaffney, C. Raison, Joonas Konki, L. G. Pedersen, K. Wrzosek-Lipska, M. Lozano, G. de Angelis, A. Illana, J. Ojala, Sebastian Rothe, Robert Page, Joakim Cederkäll, D. T. Joss, M. Zielińska, P. Van Duppen, M. Komorowska, M. Seidlitz, K. Abrahams, A. Goldkuhle, M. Bowry, P. A. Butler, N. Warr, S. Vinals, C. Henrich, and B. S. Nara Singh

Subjects
0301 basic medicine, PEAR, Multidisciplinary, Science, General Physics and Astronomy, chemistry.chemical_element, Addendum, Radon, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Archaeology, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, 030104 developmental biology, chemistry, lcsh:Q, Exotic atoms and molecules, Experimental nuclear physics, lcsh:Science, 0210 nano-technology, Geology
Abstract

5 pags., 4 figs., 1 tab. -- Addendum to: Nature Communications https://doi.org/10.1038/s41467-019-10494-5, published online 6 June 2019.

Published
2020

16. Dealing with contaminants in Coulomb excitation of radioactive beams

Author

R. Canavan, J.P. Ramos, K. Hadyńska-Klȩk, Th. Kröll, B. A. Marsh, M. Zielińska, E. Giannopoulos, Edward Simpson, T. Berry, N. Warr, S.J. Colosimo, H. Grawe, L. Kaya, Sebastian Rothe, M. Brunet, Janne Pakarinen, D. T. Doherty, F. Wenander, P. Reiter, Liam Gaffney, P. Spagnoletti, J. G. Cubiss, A. Boukhari, S. Thiel, Richard Catherall, R. Zidarova, Ch. Fransen, Y. Martinez Palenzuela, M. Rudigier, N. Lalović, Zs. Podolyák, Jose Rodriguez, Herbert Hess, G. O'Neill, H. De Witte, M. Siciliano, L. Morrison, and D. Rosiak

Subjects
Physics, History, Large Hadron Collider, 010308 nuclear & particles physics, Coulomb excitation, Subtraction procedure, tutkimuslaitteet, Contamination, hiukkaskiihdyttimet, 01 natural sciences, Accelerators and Storage Rings, Computer Science Applications, Education, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Physics - Experiment, 010306 general physics, Nuclear Experiment, ydinfysiikka, Beam (structure), Excitation, Radioactive beams
Abstract

Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN’s HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.

Published
2020

17. Population of lead isotopes in binary reactions using a Rb 94 radioactive beam

Author

Janne Pakarinen, G. de Angelis, P. Reiter, H. De Witte, Roberto Menegazzo, D. Mengoni, T. Marchi, P. Spagnoletti, P. Čolović, Zs. Podolyák, Liam Gaffney, J. G. Cubiss, A. Goasduff, E. Giannopoulos, M.L. Jurado-Gómez, A. Illana, Th. Kröll, Herbert Hess, G. Pollarolo, D. Testov, Suzana Szilner, F. Galtarossa, María José García Borge, J. J. Valiente-Dobón, Ch. Fransen, A. Boukhari, J. Snall, F. Recchia, T. Mijatović, L. Corradi, D. R. Napoli, N. Warr, G. Benzoni, D. Rosiak, R. Zidarova, S. Thiel, A. Boso, S. Ceruti, L. Kaya, E. Fioretto, G. G. O'Neill, European Commission, Science and Technology Facilities Council (UK), Croatian Science Foundation, Federal Ministry of Education and Research (Germany), Laboratoire de l'Accélérateur Linéaire (LAL), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Population, Nuclear Theory, Binary number, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Particle detector, Nuclear physics, nuclear reaction, transfer reaction, radioactive beam, 0103 physical sciences, Nuclear Reactions, Neutron, Nuclear Physics - Experiment, 010306 general physics, education, Nuclear Experiment, nuclear reactions, Physics, education.field_of_study, isotoopit, Science & Technology, Isotope, 010308 nuclear & particles physics, Physics, Nuclear, Physical Sciences, transfer reactions, Physics::Accelerator Physics, low and intermediate energy heavy-ion reactions, lyijy, models nad methods for nuclear reactions, Nucleon, ydinfysiikka, Beam (structure), Radioactive beam
Abstract

8 pags., 9 figs., We measured absolute cross sections for neutron transfer channels populated in the Rb-94 + Pb-208 binary reaction. Cross sections have been extracted identifying directly the lead isotopes with the high efficiency MINIBALL gamma-ray array coupled to a particle detector combined with a radioactive Rb-94 beam delivered at E-lab = 6.2 MeV/nucleon by the HIE-ISOLDE facility. We observed sizable cross sections in the neutron-rich mass region, where the heavy partner acquires neutrons. A fair agreement between the measured cross sections with those from GRAZING calculations gives confidence in the cross-section predictions of more neutron-rich nuclei produced via a larger number of transferred nucleons., This work was partly supported by the HORIZON 2020 ENSAR2 Grant Agreement no. 654002, and Marie Skłodowska-Curie COFUND (EU-CERN) grant agreement no. 665779, and by STFC (U.K.). This work has been supported in part by the Croatian Science Foundation under Project no. 7194 and in part under Project no. IP-2018-01- 1257, and the German BMBF under contract 05P18PKCIA + Verbundprojekt 05P2018

Published
2020
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18. Lifetimes of the 41+ states of Po206 and Po204 : A study of the transition from noncollective seniority-like mode to collectivity

Author

A. Blazhev, A. Dewald, M. Ley, A. Esmaylzadeh, L. Knafla, S. Herb, Marcus Scheck, R. Kern, L. M. Gerhard, J.-M. Régis, P. R. John, J. Jolie, J. Sinclair, Th. Kröll, P. Spagnoletti, M. Beckers, K. M. Mashtakov, J. Wiederhold, G. Rainovski, V. Werner, D. Kocheva, N. Warr, C. Sürder, L. Kornwebel, K. A. Gladnishki, C. Müller-Gatermann, K. Schomacker, V. Karayonchev, M. Djongolov, M. Stoyanova, Norbert Pietralla, J. M. Keatings, and C. Fransen

Subjects
Physics, Mode (statistics), Seniority, Atomic physics
Published
2019

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

Author

Shunji Nishimura, Yu. A. Litvinov, T. Davinson, H. J. Wollersheim, F. Nebel, K. Straub, T. Habermann, S. Schwertel, T. Faestermann, Igor T. Čeliković, P. Boutachkov, F. Farinon, C. Hinke, P. Strmeň, Hans Geissel, H. Schaffner, M. Karny, F. Nowacki, M. Lewitowicz, H. Grawe, N. Kurz, M. Górska, P. A. Söderström, G. F. Farrelly, Andreas Stolz, Zs. Podolyák, A. Atac, J. Grȩbosz, A. Prochazka, Robert Hoischen, I. Kojouharov, R. Janik, C. Scheidenberger, P. J. Woods, P. H. Regan, S. J. Steer, S. Pietri, S. Myalski, N. Braun, Roman Gernhäuser, M. Böhmer, A. Blazhev, N. Al-Dahan, Johan Nyberg, R. Krücken, A. Kaşkaş, J. Gerl, N. Alkhomashi, L. Maier, N. Goel, C. Nociforo, A. Gottardo, Zhi Liu, Catherine Rigollet, C. Domingo-Pardo, Helmut Weick, P. Doornenbal, Iris Dillmann, A. Parikh, K. Steiger, Th. Kröll, CoSee GmbH [Darmstadt], Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), SUPA School of Physics and Astronomy [Edinburgh], University of Edinburgh, Polish Academy of Sciences (PAN), Department of Physics, University of Surrey, University of Surrey (UNIS), Department of Physics, Faculty of Science, Middle East Technical University, Ankara, Turkey, Department of Fusion Plasma Physics [Stockholm] (KTH), Royal Institute of Technology [Stockholm] (KTH ), University of Cologne, Vinča Institute of Nuclear Sciences, University of Belgrade [Belgrade], Grand Accélérateur National d'Ions Lourds (GANIL), 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), Comenius University in Bratislava, University of Warsaw (UW), Faculty of Science Astronomy, Ankara University, Tandogan Ankara, TR-06100 Turkey, obasturk@ankara.edu.tr, Polska Akademia Nauk = Polish Academy of Sciences (PAN), RIKEN Nishina Center for Accelerator-Based Science [Wako] (RIKEN RNC), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Uppsala Universitet [Uppsala], Kernfysisch Versneller Instituut (KVI), University of Groningen [Groningen], Uppsala University, Michigan State University [East Lansing], Michigan State University System, RISING, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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), Blank, B., and Technische Universität München [München] (TUM)

Subjects
Sn, Nuclear and High Energy Physics, Proton, QC1-999, SHELL model, Closure (topology), Shell (structure), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Space (mathematics), 01 natural sciences, Subatomär fysik, Shell model, Fragmentation (mass spectrometry), Subatomic Physics, 0103 physical sciences, ddc:530, Neutron, 010306 general physics, Effective charges near Sn, Physics, 010308 nuclear & particles physics, Effective charges near, Polarization (waves), ddc, Effective charges near Sn-100, Electromagnetic transitions, Effective charges near 100Sn, Atomic physics
Abstract

Physics letters / B 820, 136591 (2021). doi:10.1016/j.physletb.2021.136591, Published by North-Holland Publ., Amsterdam

Published
2021

20. 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

21. Lifetime measurement around $^{132}$Sn with the ν-Ball array

Author

G Häfner, R Lozeva, A Blazhev, R L Canavan, D Etasse, J Jolie, N Jovancevic, R B Gerst, Th Kröll, M Lebois, P H Regan, M Rudigier, D Thisse, N Warr, J N Wilson, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, [PHYS]Physics [physics], History, Scintillation, Spectrometer, Fission, Nuclear Theory, Actinide, 01 natural sciences, 010305 fluids & plasmas, Computer Science Applications, Education, Nuclear physics, 0103 physical sciences, Electromagnetic shielding, Neutron source, Neutron, 010306 general physics, Spectroscopy, Nuclear Experiment
Abstract

Neutron-rich nuclei were studied after fast neutron-induced fission of 238U and 232Th at the ALTO facility in Orsay, France. The neutrons were produced with the LICORNE directional neutron source using a pulsed 7Li beam provided by the Tandem accelerator. The actinide targets were surrounded by the ν-Ball array to measure the de-excitation of fission fragments. The ν-Ball array is a hybrid spectrometer which consists of HPGe detectors (equipped with BGO shielding) and LaBr3(Ce) scintillation detectors allowing for high-resolution γ-ray spectroscopy and lifetime measurements in the ns/sub-ns range. This contribution presents preliminary results on 134Te and 137I populated in the 238U(n,f) reaction.

Published
2019

22. Microscopic structure of coexisting 0+ states in Ni68 probed via two-neutron transfer

Author

C. Bauer, A. N. Andreyev, S. Klupp, P. Reiter, J. Elseviers, F. Flavigny, R. Lutter, T. Roger, Roman Gernhäuser, Kathrin Wimmer, V. Bildstein, B. A. Marsh, N. Patronis, F. Recchia, D. Voulot, S. Sambi, S. Ilieva, F. Wenander, Jan Diriken, Th. Kröll, A. Blazhev, R. Raabe, K. Nowak, B. Siebeck, M. D. Seliverstov, Marc Huyse, B. A. Brown, M. J. Vermeulen, Takaharu Otsuka, V. N. Fedosseev, M. von Schmid, M. Seidlitz, S. Franchoo, Janne Pakarinen, P. Van Duppen, N. Warr, H. De Witte, Yusuke Tsunoda, and D. Mücher

Subjects
Physics, Ion beam, 010308 nuclear & particles physics, Nuclear structure, State (functional analysis), 01 natural sciences, Amplitude, Excited state, 0103 physical sciences, Neutron, Atomic physics, Born approximation, 010306 general physics, Ground state
Abstract

The structure of low-spin states originating from shape-coexisting configurations in $^{68}_{40}$Ni$_{28}$ was directly probed via the two-neutron transfer reaction $^{66}$Ni$(t,p)^{68}$Ni in inverse kinematics using a radioactive ion beam on a radioactive target. The direct feeding to the first excited 0$^+$ state was measured for center-of-mass angles 4°–16° and amounts to an integral of 4.2(16)% relative to the ground state. The observed difference in feeding of the 0$^+$ states is explained by the transfer of neutrons, mainly in the $pf$ shell below $N=40$ for the ground state, and across $N=40$ in the $g_{9/2}$ orbital for the 0$_2^+$, based on second-order distorted-wave Born approximation calculations combined with state-of-the-art shell-model two-nucleon amplitudes. However, the direct feeding to the 2$_1^+$ state [29(3)%] is incompatible with these calculations.

Published
2019

23. Electromagnetic properties of low-lying states in neutron-deficient Hg isotopes: Coulomb excitation of Hg-182, Hg-184, Hg-186 and Hg-188

Author

K Rezynkina, P. Marley, J. E. García-Ramos, Jan Diriken, N. Kesteloot, P. Reiter, L. M. Fraile, Mark Huyse, Kristiaan Heyde, R. D. Page, O. Ivanov, R. Gernhäuser, R. Krücken, Th. Kröll, A. C. Larsen, E. Rapisarda, Tuomas Grahn, Alick Deacon, N. Warr, A. Petts, AP Robinson, S. J. Freeman, P. J. Napiorkowski, P. Van Duppen, R-D Herzberg, Thomas Elias Cocolios, B. Bruyneel, Gry Merete Tveten, R. Orlandi, E. Piselli, Ch. Fransen, B. Bastin, Marcus Scheck, Conor Fitzpatrick, D. Voulot, Rauno Julin, Baharak Hadinia, L. Próchniak, J. Srebrny, Magne Guttormsen, Sunniva Siem, Liam Gaffney, J. L. Wood, H. Hess, Panu Rahkila, J. Van de Walle, P. A. Butler, J. F. Smith, K Singh Chakkal, D. G. Jenkins, Michaël Bender, Andreas Wiens, Andrei Andreyev, M. P. Carpenter, M. Hass, Pauli Peura, K Hadyńska-Klȩk, Janne Pakarinen, R. Lutter, Andreas Ekström, I. Stefanescu, P.-H. Heenen, Joakim Cederkäll, K. Geibel, A. Blazhev, M. Zielinska, K. Wrzosek-Lipska, E. Clément, N. Bree, N. Patronis, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Grand Accélérateur National d'Ions Lourds (GANIL), 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), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Helsinki Institute of Physics

Subjects
Moments, Intruder, 01 natural sciences, MOMENTS, Nuclear Experiment, Physics, education.field_of_study, Yrast, Bohr model, LIFETIMES, ddc, Mean field theory, symbols, Física nuclear, Atomic physics, ydinfysiikka, Configuration, Nuclear and High Energy Physics, ELECTRIC-MONOPOLE TRANSITIONS, Population, Electric-monopole transitions, DEFORMED BANDS, Lifetimes, Coulomb excitation, NUCLEAR, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 114 Physical sciences, symbols.namesake, Isomerism, SHAPE COEXISTENCE, 0103 physical sciences, Nuclear fusion, Nuclear Physics - Experiment, Neutron, Nuclear, 010306 general physics, education, CONFIGURATION, Deformed bands, 010308 nuclear & particles physics, INTRUDER, Shape coexistence, 2207 Física Atómica y Nuclear, Decay, Physics and Astronomy, 13. Climate action, ISOMERISM, Interacting boson model, DECAY
Abstract

The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass 182-188 Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of $ 0^{+}_{1,2}$01,2+, $ 2^{+}_{1,2}$21,2+and $ 4^{+}_{1}$41+states was observed in all nuclei under study. Reduced E2 matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions. The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass 182-188 Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of $ 0^{+}_{1,2}$01,2+, $ 2^{+}_{1,2}$21,2+and $ 4^{+}_{1}$41+states was observed in all nuclei under study. Reduced E2 matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions. ispartof: The European Physical Journal A - Hadrons and Nuclei vol:55 issue:8 pages:130-130 status: published

Published
2019

24. Study of medium-spin states of neutron-rich 87, 89, 91Rb isotopes

Author

S. M. Lenzi, A. M. Stefanini, S. J. Freeman, E. Sahin, Baharak Hadinia, P. T. Wady, David O'Donnell, J. F. Smith, C. A. Ur, G. de Angelis, G. Montagnoli, R. Orlandi, Suzana Szilner, M. Labiche, G. S. Simpson, A. Hodsdon, J. Ollier, T. Martinez, Z. M. Wang, A. G. Smith, E. Fioretto, Fernando Scarlassara, D. R. Napoli, V. Kumar, S. Lunardi, G. A. Jones, S. Beghini, M. Axiotis, F. Haas, J. J. Valiente-Dobón, N. Marginean, D. Bazzacco, G. Pollarolo, D. A. Torres, L. Corradi, X. Liang, N. J. Thompson, B. G. Carlsson, Morten Hjorth-Jensen, A. Gadea, D. Mengoni, T. Faul, K. M. Spohr, Th. Kröll, E. Farnea, F. Recchia, R. Mărginean, R. Chapman, F. D. Vedova, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
Physics, Nuclear and High Energy Physics, Spin states, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Fission, Yrast, Nuclear Theory, Context (language use), 01 natural sciences, Isotopes of rubidium, Nuclear physics, Excited state, 0103 physical sciences, nuclear structure, Rb isotopes, Physics::Accelerator Physics, Nuclear fusion, Neutron, Nuclear Experiment, 010306 general physics, ydinfysiikka
Abstract

International audience; Excited states of the rubidium isotopes$_{37}^{87, 89, 91}$Rb have been studied at the INFN Legnaro National Laboratory. Measurements of the $\gamma$ -ray decay of fragments produced in binary grazing reactions resulting from the interaction of a beam of 530 MeV$^{96}$Zr ions with a$^{124}$Sn target have been complemented by studies of the $\gamma$ -ray decay of fission fragments produced in the interaction of a beam of 230 MeV$^{36}$S ions with a thick$^{176}$Yb target. The structure of the yrast states of$_{37}^{87, 89, 91}$Rb has been discussed within the context of spherical shell-model and cranked Nilsson-Strutinsky calculations.

Published
2019

25. Enhanced Quadrupole and Octupole Strength in Doubly Magic Sn132

Author

Marc Huyse, Karl Johnston, Daniel Cox, P. Reiter, A. Vogt, M L Lozano Benito, J. Ojala, A. Blazhev, L. Kaya, Joakim Cederkäll, Jose Rodriguez, H. Naïdja, Tomoaki Togashi, M. Seidlitz, B. Siebeck, T. Berry, A. Illana, K. O. Zell, N. Warr, C. Henrich, F. Wenander, Janne Pakarinen, F. Nowacki, M. Queiser, H. De Witte, J. Snäll, Liam Gaffney, E. Siesling, Hie-Isolde Collaborations, D. Rosiak, Yusuke Tsunoda, María José García Borge, Miniball, G. Rainovski, K. Arnswald, Gianluca Colò, P. Van Duppen, M. von Schmid, Takaharu Otsuka, R. Hirsch, and Th. Kröll

Subjects
Physics, Large Hadron Collider, 010308 nuclear & particles physics, Projectile, Monte Carlo method, General Physics and Astronomy, Coulomb excitation, 01 natural sciences, Ion, Excited state, 0103 physical sciences, Quadrupole, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The first 2+ and 3- states of the doubly magic nucleus Sn132 are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with the highly efficient MINIBALL array. The Sn132 ions are accelerated to an energy of 5.49 MeV/nucleon and impinged on a Pb206 target. Deexciting γ rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions 0g.s.+→21+, 0g.s.+→31-, and 21+→31- in Sn132. The results on these states provide crucial information on cross-shell configurations which are determined within large-scale shell-model and Monte Carlo shell-model calculations as well as from random-phase approximation and relativistic random-phase approximation. The locally enhanced B(E2;0g.s.+→21+) strength is consistent with the microscopic description of the structure of the respective states within all theoretical approaches. The presented results of experiment and theory can be considered to be the first direct verification of the sphericity and double magicity of Sn132. (Less)

Published
2018

26. HI-TREX—A highly integrated transfer setup at REX-(HIE)ISOLDE

Author

Th. Kröll, C. Berner, Lukas Werner, and Roman Gernhäuser

Subjects
Physics, Radioactive ion beams, Nuclear and High Energy Physics, Large Hadron Collider, 010308 nuclear & particles physics, business.industry, Tandem accelerator, 01 natural sciences, Heavy ion beam, Transfer (computing), 0103 physical sciences, Electronics, 010306 general physics, business, Field-programmable gate array, Instrumentation, Computer hardware, Beam (structure)
Abstract

Transfer reactions are a unique tool to populate and probe the structure of nuclei. Due to its unprecedented capabilities in producing and accelerating exotic nuclei, the HIE-ISOLDE facility at CERN provides an excellent opportunity for transfer experiments using radioactive ion beams. We present the concept, layout and prototype measurements with the newly developed HI-TREX particle detection setup, optimized for an efficacious investigation of transfer reactions. A special focus is put on the electronics developments utilizing the custom made, FPGA based GEAR platform for reading the data from the SKIROC2 ASICs. We present performance measurements of the readout and show results from a heavy-ion beam experiment at the Munich tandem accelerator facility MLL.

Published
2021

27. Evolution of the structure of the ${4}_{1}^{+}$ states in Po isotopes

Author

M. Stoyanova, A. Dewald, A. Yaneva, C. Müller-Gatermann, V. Karayonchev, C. Fransen, M. Djongolov, R. Kern, J. Garbe, P. R. John, J. Kleemann, L. M. Gerhard, K. E. Ide, G. Rainovski, K. A. Gladnishki, J.-M. Régis, A. Blazhev, Norbert Pietralla, P. Spagnoletti, Th. Kröll, V. Werner, A. Esmaylzadeh, J. Jolie, and D. Kocheva

Subjects
Physics, Nuclear physics, History, Tandem, Scope (project management), chemistry, Isotope, Yrast, chemistry.chemical_element, Computer Science Applications, Education, Polonium
Abstract

The lifetime of the state in 208Po has been measured using γ − γ fast-timing technique with LaBr3(Ce) Detectors. The experiment was performed at the FN Tandem facility at the University of Cologne. The preliminary results are discussed in the scope of the systematic behavior of the transition strengths between yrast states in polonium isotopes.

Published
2020

28. Lifetime measurements of the low-lying excited states of 208Po

Author

K. E. Ide, L. M. Gerhard, B. Falk, C. Henrich, Th. Kröll, J. Garbe, K. A. Gladnishki, A. Dewald, R. Kern, L. Knafla, A. Blazhev, C. Fransen, M. Beckers, G. Hackenberg, M. Ley, F. Dunkel, M. Cappellazzo, V. Werner, F. Diel, I. Homm, A. Esmaylzadeh, T. Schmidt, Norbert Pietralla, L. Bussmann, R.-B. Gerst, P. Spagnoletti, L. Kornwebel, J. Jolie, A. Yaneva, D. Kocheva, M. Stoyanova, A. Goldkuhle, G. Rainovski, V. Karayonchev, M. Djongolov, Marcus Scheck, J. Kleeman, D. Kalaydjieva, and C. Müller-Gatermann

Subjects
Physics, History, Excited state, Atomic physics, Lying, Computer Science Applications, Education
Abstract

In this study we present the preliminary results about the lifetimes of the 2 2 + , 4 1 + states of 208Po and the upper limit of the lifetime of the 2 1 + state. For measuring the lifetimes of the 2 1 + and 4 1 + states the Recoil Distance Doppler Shift (RDDS) method and for the lifetime of the 2 2 + state the Doppler Shift Attenuation method (DSAM) were used. The resulting absolute transition strength B ( M 1 ; 2 2 + → 2 1 + ) ≥ 0.122 ( 20 ) μ N 2 reveals the predominant isovector nature of the 2 2 + state of 208Po.

Published
2020

29. Enhanced Quadrupole and Octupole Strength in Doubly Magic Sn 132

Author

D. Rosiak, M. Seidlitz, P. Reiter, H. Naïdja, Y. Tsunoda, T. Togashi, F. Nowacki, T. Otsuka, G. Colò, K. Arnswald, T. Berry, A. Blazhev, M. J. G. Borge, J. Cederkäll, D. M. Cox, H. De Witte, L. P. Gaffney, C. Henrich, R. Hirsch, M. Huyse, A. Illana, K. Johnston, L. Kaya, Th. Kröll, M. L. Lozano Benito, J. Ojala, J. Pakarinen, M. Queiser, G. Rainovski, J. A. Rodriguez, B. Siebeck, and E

Published
2018
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30. Coulomb Excitation of (142) Xe

Author

S. Ilieva, P. J. Napiorkowski, M. Thürauf, C. Berner, G. S. Simpson, G. Rainovski, Th. Kröll, Liam Gaffney, B. Siebeck, J. Cederkäll, M. Matejska-Minda, D. Rosiak, M. Ramdhane, R. Lozeva, L. Werner, P. Reiter, C. Berger, M. Zielinska, C. Henrich, V. Bildstein, M. Seidlitz, G. de Angelis, Daniel Cox, M. von Schmid, J. Ojala, Janne Pakarinen, G. Fernández Martínez, H. B. Rhee, J. Snäll, K. Arnswald, A. Illana Sisón, T. Berry, N. Warr, G. Georgiev, H. De Witte, V. Vaquero Soto, European Commission, Federal Ministry of Education and Research (Germany), SCOAP, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Physics, Large Hadron Collider, Spectrometer, ta114, 010308 nuclear & particles physics, Detector, Nuclear Theory, General Physics and Astronomy, ksenon, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, xenon, Nuclear physics, nuclear physics, 0103 physical sciences, Quadrupole, Physics::Accelerator Physics, Nuclear Physics - Experiment, MAGIC (telescope), ydinfysiikka, Nuclear Experiment, Beam (structure)
Abstract

5 pags., 2 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0. -- Presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Poland, September 3–9, 2017., The even–even nucleus 142Xe lies north-east of the doubly magic 132Sn on the neutron-rich side of the nuclear chart. In order to gain further information on the octupole collectivity and the evolution of quadrupole collectivity in this region, a “safe” Coulomb excitation experiment was carried out at the new HIE-ISOLDE facility (CERN) at the end of 2016. As the gamma-ray detector the Miniball spectrometer was used. Beam and target nuclei were detected using C-REX, i.e. an array of segmented Si detectors, covering forward as well as backward angles in the laboratory frame., This work is supported by the German Federal Ministry of Education and Research (BMBF) under contract 05P15RDCIA, by the EU under contract ENSAR 262010, by ISOLDE and the IS548-MINIBALL Collaboration.

Published
2018

31. Low collectivity of the 21+ state of Po212

Author

K. Moschner, D. Kocheva, P. Van Isacker, P. Spagnoletti, A. Hennig, T. Schmidt, A. Vogt, Th. Kröll, K. A. Gladnishki, C. Müller-Gatermann, J. Litzinger, J. C. Zamora, P. Scholz, C. Fransen, V. Karayonchev, R. Altenkirch, A. Blazhev, J. Jolie, A. Astier, M. Djongolov, P. Petkov, M. Bast, Marcus Scheck, F. Diel, D. Wölk, S. Ansari, J. M. Keatings, K. O. Zell, V. Werner, E. Kluge, M. Cappellazzo, R. Stegmann, M. Beckers, Norbert Pietralla, Th. Braunroth, C. Stahl, A. Dewald, A. Goldkuhle, G. Rainovski, Alexander Stolz, N. Warr, and V. Yu. Ponomarev

Subjects
Nuclear physics, Physics, 010308 nuclear & particles physics, 0103 physical sciences, State (functional analysis), 010306 general physics, 01 natural sciences
Published
2017

32. Low collectivity of the first 2$^+$ states of $^{212,210}$Po

Author

A. Astier, A. Goldkuhle, C. Müller-Gatermann, F. Diel, D. Wölk, J. Litzinger, G. Rainovski, A. Dewald, P. Scholz, S. Ansari, Th. Braunroth, J. M. Keatings, A. Vogt, Alexander Stolz, J. Jolie, M. L. Cortés, V. Yu. Ponomarev, R. Altenkirch, C. Fransen, M. Stoyanova, Norbert Pietralla, A. Hennig, P. Spagnoletti, W. Witt, N. Warr, M. Spieker, T. Schmidt, A. Blazhev, K. O. Zell, E. Kluge, R. Stegmann, V. Karayonchev, M. Djongolov, M. Rudigier, P. Thöle, M. Beckers, M. Bast, C. Stahl, D. Kocheva, V. Werner, P. Petkov, Marcus Scheck, J. C. Zamora, Th. Kröll, K. Moschner, P. Van Isacker, M. Cappellazzo, K. A. Gladnishki, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), 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, History, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Phonon, Attenuation, Yrast, Shell (structure), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Quasi particles, Computer Science Applications, Education, symbols.namesake, Recoil, Excited state, 0103 physical sciences, symbols, Atomic physics, 010306 general physics, Doppler effect
Abstract

International audience; The lifetimes of the first 2+ excited states of 212,210Po were measured in two transfer reactions 208Pb(12C,8Be)212Po and 208Pb(12C,10Be)210Po by the Recoil Distance Doppler Shift (RDDS) method and by the Doppler Shift Attenuation method (DSAM), respectively. The derived absolute B(E2) values of 2.6(3) W.u. for 212Po and 1.83(28) W.u. for 210Po indicate low collectivity. It is shown that the properties of the yrast , , and states in both nuclei cannot be described consistently in the framework of nuclear shell models. It is also demonstrated in the case of 210Po that Quasi-particle Phonon Model (QPM) calculations cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

Published
2017

33. Study of bound states in 10Be by one neutron removal reactions of 11Be

Author

K. Nowak, Roman Gernhäuser, Thomas Nilsson, D. Voulot, Jan Diriken, Liam Gaffney, V. Bildstein, Th. Kröll, K. Riisager, R. Krücken, Kathrin Wimmer, Riccardo Raabe, J. Elseviers, Björn Jonson, H. O. U. Fynbo, Olof Tengblad, M. Cubero, María José García Borge, M. Seidlitz, H. Törnqvist, Joonas Konki, V. Pesudo, D. Mücher, N. Warr, L. M. Fraile, H. De Witte, G. T. Koldste, J. G. Johansen, Janne Pakarinen, Research Foundation - Flanders, European Commission, Science and Technology Facilities Council (UK), Maier-Leibnitz-Laboratorium, Ministerio de Economía y Competitividad (España), Federal Ministry of Education and Research (Germany), Belgian Science Policy Office, and SCOAP

Subjects
Nuclear and High Energy Physics, Proton, Population, 01 natural sciences, Gamma spectroscopy, Transfer reactions, 0103 physical sciences, Bound state, Neutron, Nuclear Experiment, 010306 general physics, education, Physics, education.field_of_study, 10Be, 010308 nuclear & particles physics, Be, Charged particle, 3. Good health, Deuterium, Excited state, differential cross section, gamma spectroscopy, transfer reactions, Physics::Accelerator Physics, Atomic physics, Differential cross section, Ground state
Abstract

13 pags., 6 figs. 3 tabs.-- Open Access funded by Creative Commons Atribution Licence 3.0, The bound states of Be have been studied by removing single neutrons from Be nuclei. A 2.8 MeV u beam of Be was produced at ISOLDE, CERN and directed on to both proton and deuteron targets inducing one-neutron removal reactions. Charged particles were detected to identify the two reaction channels (d, t) and (p, d), and the individual states in Be were identified by gamma detection. All bound states but one were populated and identified in the (d, t) reaction. The combination of REX-ISOLDE and MINIBALL allowed for a clean separation of the high-lying states in Be. This is the first time these states have been separated in a reaction experiment. Differential cross sections have been calculated for all the reaction channels and compared to DWBA calculations. Spectroscopic factors are derived and compared to values from the litterature. While the overall agreement between the spectrocopic factors is poor, the ratio between the ground state and the first excited state is in agreement with the previous measured ones. Furthermore, a significant population of the state is observed, which which may indicate the presence of multi-step processes at our beam energy., This work was supported by the Danish Research Council, by the European Union Seventh Framework through ENSAR (Contract No. 262010) and a Marie Curie Actions Grant under Contract No. PIEF-GA-2008-219175, by the BMBF under Contracts No. 06MT7178, No. 06MT9156, No. 05P09PKCI5, No. 05P12PKFNE, No. 06DA9036I, No. 05P12RDCIA, No. 05P15PKCIA and Verbundprojekt 05P2015, by the Spanish MINNECO under Contracts No. FPA2012-34332 and No. FPA2015-, by the FWO-Vlaanderen (Belgium), by GOA/10/010 (BOF KU Leuven), by the Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (BriX network P7/12), by the United Kingdom Science and Technology Facilities Council, and by Maier-Leibnitz-Laboratorium, Garching.

Published
2017

34. Study of the deformation-drivingνd5/2orbital in 67 28 Ni 39 using one-neutron transfer reactions

Author

V. Bildstein, B. A. Marsh, T. J. Mertzimekis, Roman Gernhäuser, A. Pakou, J. Jolie, D. Muecher, R. Orlandi, G. Randisi, A. Blazhev, Ch. Fransen, S. Antalic, H. De Witte, J. Elseviers, D. Voulot, C. Sotty, N. Patronis, Herbert Hess, P. Reiter, Kathrin Wimmer, F. Nowacki, R. Krücken, Fredrik Wenander, F. Flavigny, J. Eberth, Kamila Sieja, Riccardo Raabe, Th. Kröll, H. Törnqvist, Georgi P. Georgiev, Iain Darby, N. Warr, Marc Huyse, V. N. Fedosseev, Andrei Andreyev, R. Lutter, M. Seidlitz, Jan Diriken, T. Roger, M. D. Seliverstov, P. Van Duppen, and J. Van de Walle

Subjects
Physics, Nuclear and High Energy Physics, Atomic orbital, Nuclear structure, Neutron, Astrophysics::Earth and Planetary Astrophysics, Deformation (meteorology), Atomic physics
Abstract

The νg9/2, d5/2, s1/2 orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below 68 Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby

Published
2014

35. Decay properties of the ${3}_{1}^{-}$ level in 96Mo

Author

K. R. Mashtakov, R. Chapman, J. Jolie, J. M. Keatings, G. S. Simpson, M. Thürauf, K. O. Zell, M. Zielińska, R. Leguillon, C. M. Petrache, Paolo Mutti, N N Arsenyev, Marcus Scheck, Michael Jentschel, David O'Donnell, W. Urban, A A Dzhioev, P. Spagnoletti, J. Sinclair, E. T. Gregor, Th. Kröll, T. Soldner, J. R. Vanhoy, V. Werner, F. Drouet, A. Vancraeyenest, T.M. Shneidman, A. V. Sushkov, J. F. Smith, Aurelien Blanc, C. Bernards, and Ulli Köster

Subjects
Physics, Nuclear and High Energy Physics, Isovector, Isotope, 010308 nuclear & particles physics, Branching fraction, 7. Clean energy, 01 natural sciences, Neutron capture, Neutron flux, Excited state, 0103 physical sciences, Quadrupole, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Random phase approximation
Abstract

The first excited level of 96Mo was investigated in a high-statistics experiment using the 95Mo(n, γγ) cold neutron capture reaction. The measurements used the high cold neutron flux from the research reactor at Institut Laue-Langevin and employed the highly-efficient EXILL array to detect γ-ray coincidences. The recorded statistics allow identification of decay branches with only a small relative intensity including the E3 decay. With the knowledge of the newly measured branching ratio and the known transition probability, the lifetime of the level was determined and, subsequently, the strength of the other decay branches of the octupole phonon were calculated. The extracted electromagnetic decay strengths are compared to the systematics of the stable even–even molybdenum isotopes and values calculated in a Skyrme-force based quasiparticle random phase approximation and in a cluster approach. Additionally, the decay branch to the low-lying quadrupole isovector level was observed.

Published
2019

36. Measurement of picosecond lifetimes in neutron-rich Xe isotopes

Author

S. Ilieva, Th. Kröll, J.-M. Régis, N. Saed-Samii, A. Blanc, A. M. Bruce, L. M. Fraile, G. de France, A.-L. Hartig, C. Henrich, A. Ignatov, M. Jentschel, J. Jolie, W. Korten, U. Köster, S. Lalkovski, R. Lozeva, H. Mach, N. Mărginean, P. Mutti, V. Paziy, P. H. Regan, G. S. Simpson, T. Soldner, M. Thürauf, C. A. Ur, W. Urban, N. Warr, Institut Laue-Langevin (ILL), ILL, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, Nuclear Theory, chemistry.chemical_element, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Xenon, chemistry, Neutron number, Excited state, 0103 physical sciences, Quadrupole, Neutron, Física nuclear, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

EXILL&FATIMA campaign; International audience; Background: Lifetimes of nuclear excited states in fission fragments have been studied in the past followingisotope separation, thus giving access mainly to the fragments’ daughters and only to long-lived isomeric statesin the primary fragments. For the first time now, short-lived excited states in the primary fragments, producedin neutron-induced prompt fission of 235U and 241Pu, were studied within the EXILL&FATIMA campaign at theintense neutron-beam facility of the Institute Laue-Langevin in Grenoble.Purpose: We aim to investigate the quadrupole collective properties of neutron-rich even-even 138,140,142Xeisotopes lying between the double shell closure N = 82 and Z = 50 and a deformed region with octupolecollectivity.Method: The γ rays emitted from the excited fragments were detected with a mixed array consisting of 8 HPGeEXOGAM Clover detectors (EXILL) and 16 LaBr3(Ce) fast scintillators (FATIMA). The detector system hasthe unique ability to select the interesting fragment making use of the high resolution of the HPGe detectorsand determine subnanosecond lifetimes using the fast scintillators. For the analysis the generalized centroiddifference method was used.Results: We show that quadrupole collectivity increases smoothly with increasing neutron number above theclosed N = 82 neutron shell. Our measurements are complemented by state-of-the-art theory calculations basedon shell-model descriptions.Conclusions: The observed smooth increase in quadrupole collectivity is similar to the evolution seen in themeasured masses of the xenon isotopic chain and is well reproduced by theory. This behavior is in contrast tohigher Z even-even nuclei where abrupt change in deformation occurs around N = 90.

Published
2016

37. Collective 2$^{+1}$ excitations in$^{206}$Po and$^{208,210}$Rn

Author

C. Bernards, P. Reiter, Jouni Suhonen, E. Rapisarda, H. De Witte, Marcus Scheck, V. Werner, Joonas Konki, A. Vogt, Rauno Julin, M. Thürauf, K. Reynders, J. Elseviers, A. Damyanova, S. Sambi, T. Grahn, T. Steinbach, K. Wrzosek-Lipska, M. Rudiger, C. Bauer, T. De Coster, M. J. Vermeulen, M. Venhart, Liam Gaffney, M. Zielińska, M. Pfeiffer, Martin Veselsky, D. Radeck, P. Peura, N. Kesteloot, Th. Kröll, S. Bönig, Marc Huyse, S. Stolze, L. Lewandowski, B. Siebeck, U. Jakobsson, K. Auranen, M. Seidlitz, Panu Rahkila, A. Herzáň, A. Blazhev, P. Thoele, Janne Pakarinen, M. D. Salsac, Lotta Jokiniemi, M. Albers, P. A. Butler, K. Moschner, P. Van Duppen, N. Warr, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Nuclear Theory, radon, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Isotopes of palladium, collective excitation, Excited state, 0103 physical sciences, Quasiparticle, Physics::Accelerator Physics, Atomic physics, 010306 general physics, Nuclear Experiment, Open shell, polonium, Excitation, excited states
Abstract

In the present study, $B(E2; 2^{+}_{1}\rightarrow 0^{+}_{1})$ values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the $2^{+}_{1}\rightarrow 0^{+}_{1}$ transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRPA framework.

Published
2016

38. Application of a double-sided silicon-strip detector as a differential pumping barrier for NESR experiments at FAIR

Author

H. Kollmus, Th. Kröll, P. Egelhof, S. Ilieva, B. Streicher, Nasser Kalantar-Nayestanaki, M. von Schmid, M. Mutterer, M. Träger, and KVI - Center for Advanced Radiation Technology

Subjects
Physics, Nuclear and High Energy Physics, Work (thermodynamics), Silicon, business.industry, Orders of magnitude (temperature), Physics::Instrumentation and Detectors, Detector, Differential vacuum, chemistry.chemical_element, Outgassing, Optics, Recoil, chemistry, Double-sided silicon-strip detector, Grid-leak detector, business, Instrumentation, Storage ring
Abstract

The presented work focuses on the development of a differential pumping system using double-sided silicon-strip detectors to separate the ultra-high vacuum of a storage ring from subsequent detectors and outgassing components placed in an auxiliary vacuum. Such a technical concept will give the opportunity to use telescope-like detector systems in an ultra-high vacuum environment, such as a storage ring, without enclosing the entire system in a pocket. Therefore, it will enable the detection of recoil particles with the smallest possible energy due to the use of the innermost strip detector as an active window. Our results prove that such an assembly is feasible without having an effect, within experimental errors, on the performance of the strip detector. Vacuum separation better than six orders of magnitude was achieved with the ultra-high vacuum side reaching down to the 10(-10) mbar pressure region. (C) 2011 Elsevier B.V. All rights reserved.

Published
2011

39. Application of the Recursive Subtraction Pulse Shape Analysis algorithm to in-beam HPGe signals

Author

Th. Kröll, V. Vandone, A. Gadea, C. A. Ur, F. C. L. Crespi, F. Recchia, F. Camera, D. Bazzacco, A. Bracco, Benedicte Million, D. Mengoni, O. Wieland, and E. Farnea

Subjects
Physics, Nuclear and High Energy Physics, Tracking, HPGe detectors, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Subtraction, Tracking (particle physics), Signal, Pulse (physics), Semiconductor detector, Distribution (mathematics), AGATA, Gamma-rays, Pulse Shape Analysis, Instrumentation, Algorithm, Beam (structure)
Abstract

The Pulse Shape Analysis algorithm “Recursive Subtraction” has been applied to data acquired during the in-beam tests of two different highly segmented HPGe detectors. This algorithm processes the net charge signal, determining the number of interactions per segment and their radial coordinates. The RS algorithm performances are evaluated by comparing the results obtained following its application to experimental pulse shapes with those obtained with specific GEANT simulations. Excellent agreement is found between the experimental distribution of the number of interactions per segment and the simulated one. Deviations between experimental radial distribution and the calculated ones are discussed.

Published
2009

40. Spectroscopy of neutron-rich nuclei at REX-ISOLDE with MINIBALL

Author

Th. Kröll

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Theoretical models, Coulomb excitation, Atomic and Molecular Physics, and Optics, Nuclear physics, Excited state, Physics::Accelerator Physics, Neutron, Statistical physics, Nuclear Experiment, Spectroscopy
Abstract

We report on “safe” Coulomb excitation of neutron-rich nuclei. The radioactive nuclei have been produced by ISOLDE at CERN and postaccelerated by the REX-ISOLDE facility. The γ rays emitted by the decay of excited states have been detected by the MINIBALL array. Recent results are presented and compared to theoretical models.

Published
2007

41. Experimental study of theNi66(d,p) Ni67one-neutron transfer reaction

Author

C. Sotty, D. Voulot, Th. Kröll, F. Wenander, R. Raabe, D. Muecher, V. Bildstein, V. N. Fedosseev, M. D. Seliverstov, B. A. Marsh, M. Seidlitz, Roman Gernhäuser, P. Reiter, T. Roger, Hans-Jurgen E. Hess, Kathrin Wimmer, A. Pakou, Georgi P. Georgiev, A. Blazhev, J. Van de Walle, F. Flavigny, Jan Diriken, Marc Huyse, A. N. Andreyev, J. Elseviers, N. Patronis, R. Lutter, J. Jolie, G. Randisi, P. Van Duppen, N. Warr, J. Eberth, H. Törnqvist, T. J. Mertzimekis, R. Orlandi, I. G. Darby, Ch. Fransen, S. Antalic, R. Krücken, and H. De Witte

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, Atomic orbital, Excited state, 0103 physical sciences, Quadrupole, Neutron, Born approximation, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The quasi-SU(3) sequence of the positive parity $\ensuremath{\nu}{g}_{9/2},{d}_{5/2},{s}_{1/2}$ orbitals above the $N=40$ shell gap are assumed to induce strong quadrupole collectivity in the neutron-rich Fe $(Z=26)$ and Cr $(Z=24)$ isotopes below the nickel region. In this paper the position and strength of these single-particle orbitals are characterized in the neighborhood of $^{68}\mathrm{Ni} (Z=28,\phantom{\rule{0.16em}{0ex}}N=40)$ through the $^{66}\mathrm{Ni}(d,p)^{67}\mathrm{Ni}$ one-neutron transfer reaction at 2.95 MeV/nucleon in inverse kinematics, performed at the REX-ISOLDE facility in CERN. A combination of the Miniball $\ensuremath{\gamma}$-array and T-REX particle-detection setup was used and a delayed coincidence technique was employed to investigate the 13.3-$\ensuremath{\mu}\mathrm{s}$ isomer at 1007 keV in $^{67}\mathrm{Ni}$. Excited states up to an excitation energy of 5.8 MeV have been populated. Feeding of the $\ensuremath{\nu}{g}_{9/2}$ (1007 keV) and $\ensuremath{\nu}{d}_{5/2}$ (2207 keV and 3277 keV) positive-parity neutron states and negative parity $(\ensuremath{\nu}pf)$ states have been observed at low excitation energy. The extracted relative spectroscopic factors, based on a distorted-wave Born approximation analysis, show that the $\ensuremath{\nu}{d}_{5/2}$ single-particle strength is mostly split over these two excited states. The results are also compared to the distribution of the proton single-particle strength in the $^{90}\mathrm{Zr}$ region $(Z=40,N=50)$.

Published
2015

42. Erratum to 'Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions' [Phys. Lett. B 736 (2014) 533–538]

Author

A. N. Andreyev, Marc Huyse, A. Blazhev, C. Sotty, Georgi P. Georgiev, P. Reiter, F. Nowacki, J. Jolie, D. Muecher, B. A. Marsh, Kamila Sieja, Jan Diriken, D. Voulot, V. N. Fedosseev, F. Wenander, J. Elseviers, J. Van de Walle, N. Patronis, M. D. Seliverstov, Herbert Hess, F. Flavigny, Kathrin Wimmer, V. Bildstein, G. Randisi, R. Orlandi, I. G. Darby, Ch. Fransen, S. Antalic, Roman Gernhäuser, M. Seidlitz, P. Van Duppen, R. Krücken, Th. Kröll, T. J. Mertzimekis, R. Lutter, J. Eberth, H. Törnqvist, T. Roger, H. De Witte, N. Warr, R. Raabe, and A. Pakou

Subjects
Physics, Nuclear and High Energy Physics, Condensed matter physics, Neutron, Deformation (meteorology), lcsh:Physics, lcsh:QC1-999
Published
2015
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43. Low-energy Coulomb excitation of $^{62}$Fe and $^{62}$Mn following in-beam decay of $^{62}$Mn

Author

V. Bildstein, H. Hess, P. Reiter, Jan Diriken, Th. Kröll, Mark Huyse, Valentin Fedosseev, Douglas D. DiJulio, N. Bree, H. De Witte, I. G. Darby, Ch. Fransen, P. Van Duppen, K. Wrzosek-Lipska, B. Bastin, N. Warr, R. Lutter, N. Kesteloot, R. Gernhäuser, Fredrik Wenander, M. Seidlitz, A. Gustafsson, J. Van de Walle, D. Voulot, Liam Gaffney, Joakim Cederkäll, A. Blazhev, B. A. Marsh, Kathrin Wimmer, 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), CERN [Genève], 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, Nuclear and High Energy Physics, education.field_of_study, Population, Order (ring theory), FOS: Physical sciences, Charge (physics), Coulomb excitation, Trapping, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Ionization, Atomic physics, Nuclear Experiment (nucl-ex), education, Nuclear Experiment, Beam (structure), Excitation
Abstract

Sub-barrier Coulomb-excitation was performed on a mixed beam of $^{62}$Mn and $^{62}$Fe, following in-trap $\beta^{-}$ decay of $^{62}$Mn at REX-ISOLDE, CERN. The trapping and charge breeding times were varied in order to alter the composition of the beam, which was measured by means of an ionisation chamber at the zero-angle position of the Miniball array. A new transition was observed at 418~keV, which has been tentatively associated to a $(2^{+},3^{+})\rightarrow1^{+}_{g.s.}$ transition. This fixes the relative positions of the $\beta$-decaying $4^{+}$ and $1^{+}$ states in $^{62}$Mn for the first time. Population of the $2^{+}_{1}$ state was observed in $^{62}$Fe and the cross-section determined by normalisation to the $^{109}$Ag target excitation, confirming the $B(E2)$ value measured in recoil-distance lifetime experiments., Comment: 9 pages, 10 figures

Published
2015

44. The (n,γ) campaigns at EXILL

Author

R. Lica, S. Kisyov, W. Urban, D. Curien, M. Zielinska, G. Bocchi, M. Czerwinski, Michael Jentschel, M. Pfeiffer, Henryk Mach, J. Jolie, G. Benzoni, G.S. Simpson, B. Szpak, N. Saed-Samii, S. Leoni, D. Ivanova, W. Korten, R. Leguillon, P. H. Regan, N. Marginean, S. Lalkovski, C. Bernards, N. Cieplicka, P. G. Thirolf, L. Sengele, S. Bottoni, T. Rzaca-Urban, R. B. Cakirli, Paolo Mutti, Ralph Massarczyk, S. Ilieva, C. Lorenz, Dietrich Habs, A. Korgul, P. Ba̧czyk, R. F. Casten, Marcus Scheck, N. Warr, Oliver J. Roberts, Ulli Köster, L. M. Fraile, C. M. Petrache, J.-M. Régis, F. C. L. Crespi, V. Paziy, Zs. Podolyák, A. Ignatov, Th. Kröll, B. Fornal, D. Wilmsen, Alison Bruce, R. Lozeva, T. Soldner, S. Ahmed, M. D. Salsac, A. Vancraeyenest, C. A. Ur, V. Werner, C. Mazzocchi, F. Drouet, Ronald Schwengner, M. Thürauf, Aurelien Blanc, R. John, and N. Cooper

Subjects
Nuclear physics, Physics, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Astrophysics, Neutron radiation, Scintillator, Coincidence, Collimated light
Abstract

At the PF1B cold neutron beam line at the Institut Laue Langevin, the EXILL array consisting of EXOGAM, GASP and ILL-Clover detectors was used to perform (n,$\gamma$) measurements at very high coincidence rates. About ten different reactions were measured in autumn 2012 using a highly collimated cold neutron beam. In spring 2013, the EXOGAM array was combined with 16 LaBr3(Ce) scintillators in the EXILL&FATIMA campaign for the measurement of lifetimes using the generalised centroid difference method. We report on the properties of the set-ups and present first results from both campaigns.

Published
2015

45. Test of the SO(6) selection rule in $^{196}$Pt using cold-neutron capture

Author

M. Pfeiffer, D. Wilmsen, Zs. Podolyák, R. Lica, Alison Bruce, F. Drouet, J.-M. Régis, W. Korten, A. Vancraeyenest, S. Kisyov, W. Urban, Ulli Köster, N. Saed-Samii, D. Ivanova, Aurelien Blanc, Michael Jentschel, A. Ignatov, J. Jolie, Torsten Soldner, G.S. Simpson, P. Mutti, Th. Kröll, V. Paziy, L. M. Fraile, P. H. Regan, N. Marginean, E. Wilson, N. Warr, C. A. Ur, Oliver J. Roberts, S. Lalkovski, Institut Laue-Langevin (ILL), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, ILL, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and 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)

Subjects
Physics, Nuclear and High Energy Physics, Detector, State (functional analysis), Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Collimated light, Nuclear physics, Neutron capture, Beamline, Interacting boson model, Atomic physics, Beam (structure), ComputingMilieux_MISCELLANEOUS
Abstract

At the PF1B cold-neutron beam line of the Institut Laue Langevin, the EXILL&FATIMA array, consisting of EXOGAM Ge detectors and fast LaBr3(Ce) scintillators, was used to perform fast electronic timing measurements after the 195Pt(n, γ) reaction using a highly collimated cold-neutron beam. An upper lifetime limit was obtained for the third 0 + state in 196Pt. As this state is the lowest state of the σ = N − 2 set of SO(6) states, the selection rule which forbids E2 transitions to the lower lying σ = N could be tested.

Published
2015

46. A genetic algorithm for the decomposition of multiple hit events in the γ-ray tracking detector MARS

Author

Th. Kröll and D. Bazzacco

Subjects
Physics, Nuclear and High Energy Physics, Distribution (mathematics), Genetic algorithm, Detector, Process (computing), A priori and a posteriori, Mars Exploration Program, Base (topology), Tracking (particle physics), Instrumentation, Algorithm
Abstract

A crucial step in the process of γ -ray tracking is the determination of the interaction points of the γ -rays within the detectors. This can be achieved by pulse shape analysis of the signals from highly segmented HPGe detectors. We present an approach for this task based on a genetic algorithm. Our algorithm makes no a priori assumption on the distribution of interaction points and hit segments in the detector but addresses the decomposition problem in full generality. In the analysis of simulated signals the number of interactions can be determined at a success rate of up to 83% and the interaction points can be localised within an average positional error in the order of 2.5–5.4 mm. Similar positional errors have been obtained also in the analysis of measured signals, demonstrating the capability of our approach to decompose measured multiple hit events using a base system of calculated signals.

Published
2006

47. Shape transitions far from stability: The nucleus 58Cr

Author

W. Zhimin, D. Bazzacco, A. M. Bizzeti-Sona, K. M. Spohr, A. Gadea, A. Iordachescu, S. Lunardi, B. R. Behera, P. G. Bizzeti, D. R. Napoli, C. A. Ur, S. M. Lenzi, E. Fioretto, Th. Kröll, J. F. Smith, S. J. Freeman, N. Marginean, R. Marginean, A. M. Stefanini, E. Farnea, M. Ionescu-Bujor, B. J. Varley, A. Latina, G. de Angelis, F. Scarlassara, R. Chapman, G. Montagnoli, S. Beghini, L. Corradi, M. Trotta, G. Pollarolo, M. Nespolo, D. Bucurescu, C. Rusu, A. N. Deacon, X. Liang, F. Della Vedova, and Suzana Szilner

Subjects
Neutron-rich nuclei, Physics, Nuclear and High Energy Physics, Phase transition, Spectrometer, Critical point (mathematics), IBM, Multinucleon transfer reactions, Shell model, High-spin spectroscopy, medicine.anatomical_structure, Excited state, medicine, Neutron, Interacting boson model, Atomic physics, Nucleus, Excitation
Abstract

Excited states up to I π = 8 + in the neutron-rich nucleus 58Cr have been identified by using a new experimental setup composed of the large acceptance magnetic spectrometer PRISMA and the highly efficient γ-detector array CLARA. Interestingly, the excitation energy sequence of the ground-state band follows the one expected by the E ( 5 ) dynamical symmetry for a nucleus at the critical point of the shape phase transition from a spherical vibrator ( U ( 5 ) ) to a γ-soft rotor ( O ( 6 ) ). For the first time, in the same physical system, large scale shell-model calculations in the full fp shell are compared to the E ( 5 ) analytical model results and to the Interacting Boson Model. The theoretical results are in excellent agreement with the present data.

Published
2006

48. High spin studies of the Er and Tm isotopes aroundA= 166

Author

T. Martinez, C. A. Ur, E. Farnea, K. M. Spohr, R. Chapman, Th. Kröll, M. Axiotis, M. Burns, X. Liang, D. R. Napoli, M. Labiche, and J. Ollier

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Fusion, Spin states, Isotope, Nuclear fusion, Atomic physics, Spin (physics), Charged particle, Beam (structure), Ion
Abstract

Fusion and incomplete fusion evaporation channels were studied in the 7Li +164Dy reaction at the INFN Laboratory, Legnaro, Italy. The Tandem-XTU accelerator was used to accelerate a beam of 7Li ions to 55 MeV. The highly sensitive GASP γ-detector array coupled with the selectivity of the ISIS charged particle ΔE–E telescope array provided a powerful tool for studies of high spin states in the fusion and incomplete fusion reaction products. Rotational sequences in the Er and Tm isotopes around A = 166 have been observed and extended to higher spin states. Comparisons of the experimental data with the results of the cranked shell model give some insight into the configuration dependence of the crossing of the ground-state band with the aligned i13/2 two quasineutron configuration.

Published
2005

49. Population of yrast states in191Os using deep-inelastic reactions

Author

A. Gadea, S D Langdown, P. G. Bizzeti, R. Broda, B. Rubio, W. Gelletly, J. J. Valiente-Dobón, M. Axiotis, C. A. Ur, P. M. Walker, S. J. Williams, D. Bucurescu, N. Marginean, M. Ionescu-Bujor, E. Farnea, F. Brandolini, Y. H. Zhang, Nilberto H. Medina, G A Jones, Th. Kröll, Zs. Podolyák, Begoña Quintana, A. Iordachescu, D. Bazzacco, S. Lunardi, P. H. Regan, G. de Angelis, and T. Martinez

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, Branching fraction, Yrast, Population, Atomic physics, education, National laboratory
Abstract

Several nuclei in the A ∼ 190 region have been studied following deep-inelastic reactions using a 460 MeV 82 Se projectile impinging upon a thick 192 Os target. The GASP array (at the Legnaro National Laboratory in Italy) was used to measure the resulting γ-decays. The previously reported near-yrast structure of 191 Os is extended to a t 1 /2= 61 ns isomer, at an energy of 2640 keV. Branching ratios for ΔI = 1 and A/ = 2 transitions in the K π = 11/2 + band have been measured, giving |(g K - g R )/Q 0 | = 0.022(3) and 0.024(7) for transitions from the 17/2 + and (19/2 + ) states respectively. These are consistent with the theoretical calculation for the proposed v11/2 + [615] configuration of the band. Nilsson plus BCS calculations reveal that the isomer is likely to have a {v11/2 + [615] ⊗ π11/2-[505] ⊗ π9/2-[514]} configuration with J π = K π = 31/2 + . This yields an implied reduced hindrance of f v = 1.9, in accordance with empirical systematics of K isomers in the A ∼ 180-190 region.

Published
2005

50. Planar and aplanar tilted bands in the odd–odd nucleus132Cs

Author

Th. Kröll, K. Starosta, D. B. Fossan, P. J. Nolan, G. Rainovski, Anthony J. H. Simons, E. S. Paul, P. Raddon, E. Farnea, Takeshi Koike, G. de Angelis, C. Vaman, V. I. Dimitrov, D. Curien, R. Wadsworth, D. G. Jenkins, Roberto Isocrate, H. J. Chantler, and A. Gadea

Subjects
Physics, Nuclear and High Energy Physics, Dipole, Angular momentum, Total angular momentum quantum number, Linear polarization, Angular momentum of light, Angular momentum coupling, Orbital angular momentum of light, Atomic physics, Principal axis theorem
Abstract

High-spin states in the doubly odd N = 77 nucleus 132Cs have been studied. Gamma-ray linear polarization and angular correlation measurements have been performed to determine the spin and parity of the states. A rotational sequence of enhanced dipole transitions was established. This band can be described within the framework of the the tilted axis cranking (TAC) model as a band based on a weakly deformed structure in which the total angular momentum vector does not coincide with any of the principal axes of the triaxial nucleus but still is in the plane defined by the short and long axes. The theoretical description of the previously proposed chiral bands in 132Cs was extended in the framework of the core–particle coupling model (CPCM) confirming that the total angular momentum for the πh11/2 ⊗ νh11/2 configuration is well outside any planes defined by the principal axes of the nucleus and revealing the important role of the residual proton–neutron interaction between the valence particles.

Published
2003

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