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69 results on '"M. L. Cortés"'

1. Temperature-dependent relative self-absorption measurements in 27Al

Author

Pavlos Koseoglou, M. L. Cortés, J. Isaak, V. Werner, O. Papst, J. Kleemann, M. Beuschlein, N. Pietralla, U. Ahmed, K. E. Ide, I. Jurosevic, C. Nickel, M. Spall, T. Stetz, and R. Zidarova

Subjects
General Medicine
Abstract

Nuclear resonance fluorescence measurements provide direct sensitivity to ground-state transition widths by probing the photoexcitation process of nuclear resonances. A technique in Relative Self-Absorption (RSA) measurements, in which measurements are done at multiple absorber temperatures, was developed and tested with 27Al at the Darmstadt High Intensity Photon Setup of the Superconducting Darmstadt Linear Accelerator. The advantage of this technique, over the regular RSA, is the possibility to overcome the need for theory input on the effective temperatures and the uncertainties that they introduce in the measured level widths. The technique and the preliminary results of the first test-measurements are presented in this proceedings.

Published
2022

2. Extended p3/2 Neutron Orbital and the N=32 Shell Closure in Ca52

Author

M. Enciu, H. N. Liu, A. Obertelli, P. Doornenbal, F. Nowacki, K. Ogata, A. Poves, K. Yoshida, N. L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, P. J. Li, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti

Subjects
General Physics and Astronomy
Published
2022

3. γ -ray spectroscopy of low-lying yrast and non-yrast states in neutron-rich Kr94,95,96

Author

R.-B. Gerst, A. Blazhev, K. Moschner, P. Doornenbal, A. Obertelli, K. Nomura, J.-P. Ebran, S. Hilaire, J. Libert, G. Authelet, H. Baba, D. Calvet, F. Château, S. Chen, A. Corsi, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, V. Lapoux, T. Motobayashi, M. Niikura, N. Paul, J.-Y. Roussé, H. Sakurai, C. Santamaria, D. Steppenbeck, R. Taniuchi, T. Uesaka, T. Ando, T. Arici, F. Browne, A. M. Bruce, R. Caroll, L. X. Chung, M. L. Cortés, M. Dewald, B. Ding, F. Flavigny, S. Franchoo, M. Górska, A. Gottardo, J. Jolie, A. Jungclaus, J. Lee, M. Lettmann, B. D. Linh, J. Liu, Z. Liu, C. Lizarazo, S. Momiyama, S. Nagamine, N. Nakatsuka, C. R. Nita, C. Nobs, L. Olivier, R. Orlandi, Z. Patel, Zs. Podolyák, M. Rudigier, T. Saito, C. Shand, P.-A. Söderström, I. Stefan, V. Vaquero, V. Werner, K. Wimmer, and Z. Xu

Published
2022

4. Investigation of the ground-state spin inversion in the neutron-rich Cl47,49 isotopes

Author

Jason D. Holt, Carlo Barbieri, Zaihong Yang, I. Murray, D. M. Rossi, K. I. Hahn, S. Y. Park, C. Hilaire, Kazuyuki Ogata, C. Lehr, H. Baba, Duo Yan, David Steppenbeck, H. Törnqvist, P. Koseoglou, Masahiro Yasuda, V. Lapoux, Yasuhiro Togano, N. L. Achouri, R.-B. Gerst, Alessandra Corsi, T. Lokotko, B. D. Linh, L. Stuhl, H. Wang, Dóra Sohler, M. Gómez-Ramos, Igor Gašparić, H. N. Liu, Y. L. Sun, Takashi Nakamura, E. Sahin, Petr Navrátil, V. Panin, W. Rodriguez, N. Shimizu, J. M. Gheller, A. Moro, Victor Vaquero, L. X. Chung, Thomas Duguet, K. Moschner, Hiroyoshi Sakurai, Kathrin Wimmer, Dong-Wook Kim, A. Delbart, N. T. Khai, V. Wagner, N. Paul, P. Doornenbal, T. Motobayashi, V. Somà, D. Calvet, T. Isobe, K. Yoneda, O. Aktas, V. Werner, Y. Yamada, Thomas Aumann, F. Flavigny, N. D. Ton, T. Kobayashi, A. Giganon, X. X. Xu, F. Château, Hideaki Otsu, Julien Gibelin, Si-Ge Chen, N. T. T. Phuc, P. A. Söderström, A. Gillibert, Nobuyuki Chiga, A. Obertelli, T. Koiwai, Tomohiro Uesaka, F. Browne, M. MacCormick, Satoshi Takeuchi, M. L. Cortés, Masaki Sasano, S. Franchoo, Yutaka Utsuno, Jenny Lee, Yuya Kubota, L. Zanetti, and Yosuke Kondo

Subjects
Physics, Isotope, 010308 nuclear & particles physics, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spin (physics), Ground state, 01 natural sciences, Inversion (discrete mathematics), Nuclear theory
Published
2021

5. Spectroscopy of Cd98 by two-nucleon removal from In100

Author

Joochun Park, Cenxi Yuan, K. Wimmer, F. Browne, I. Zanon, S. T. Wang, Luis Sarmiento Pico, Sidong Chen, P Liang, T. Lokotko, Alessandra Corsi, Ryo Taniuchi, Zhengtai Liu, K. Kokubun, T. Koiwa, Jenny Lee, D. Brugnara, Hiroyoshi Sakurai, Joakim Cederkäll, P. Doornenbal, Jinjia Liu, Sun Zhipeng, W. Xian, P. Li, Shan Jin, J. Gerl, G. Häfner, Shigeru Kubono, Alejandro Algora, M. L. Cortés, M. Górska, and P. Koseoglou

Subjects
Physics, Proton, 010308 nuclear & particles physics, Space (mathematics), 01 natural sciences, 7. Clean energy, Atomic orbital, Yield (chemistry), 0103 physical sciences, Level structure, Atomic physics, 010306 general physics, Spectroscopy, Nucleon, Excitation
Abstract

Low-lying states of Cd-98 have been populated by the two-nucleon removal reaction (In-100, Cd-98+gamma) and studied using in-beam gamma-ray spectroscopy at the Radioactive Isotope Beam Factory at RIKEN. Two new gamma transitions were identified and assigned as decays from a previously unknown state. This state is suggested to be based on a pi 1g(/9/2)(-1)2p(1/2)(-2) configuration with J(pi) = 5(-). The present observation extends the systematics of the excitation energies of the first 5(-) state in N = 50 isotones toward Sn-100. The determined energy of the 5(- )state in Cd-98 continues a smooth trend along the N = 50 isotones. The systematics are compared with shell-model calculations in different model spaces. Good agreement is achieved when considering a model space consisting of the pi(1f(5/2), 2p(3/2), 2p(1/2), 1g(9/2)) orbitals. The calculations with a smaller model space omitting the orbitals below the Z = 38 subshell could not reproduce the experimental energy difference between the ground and first 5(-) states in N = 50 isotones, because proton excitations across Z = 38 subshell yield a large amount of correlation energy that lowers the ground states. (Less)

Published
2021

6. Pairing Forces Govern Population of Doubly Magic Ca54 from Direct Reactions

Author

J. M. Gheller, S. Y. Park, K. Yoneda, Masaki Sasano, P. A. Söderström, D. Sohler, D. Körper, H. Simon, A. Gillibert, K. Miki, Satoshi Takeuchi, Yasuhiro Togano, M. MacCormick, R.-B. Gerst, Duo Yan, Tomohiro Uesaka, Fabia Schindler, V. Wagner, B. D. Linh, M. Holl, A. Corsi, N. Paul, Igor Gašparić, H. N. Liu, P. Koseoglou, E. Sahin, Yosuke Kondo, T. Lokotko, T. Isobe, Victor Vaquero, M. L. Cortés, V. Werner, Takashi Nakamura, W. Rodriguez, Zaihong Yang, A. Delbart, S. Franchoo, F. Château, V. Lapoux, P. Doornenbal, K. I. Hahn, L. Stuhl, I. Murray, C. Caesar, Kazuyuki Ogata, C. Lehr, T. Kobayashi, X. X. Xu, C. Hilaire, Si-Ge Chen, Yutaka Utsuno, V. Panin, A. Giganon, Jenny Lee, N. L. Achouri, L. X. Chung, Y. L. Sun, K. Moschner, Yuya Kubota, D. M. Rossi, H. Baba, F. Flavigny, Masahiro Yasuda, L. Zanetti, Kathrin Wimmer, Dong-Wook Kim, O. Aktas, F. Browne, S. Wang, A. Obertelli, J. Kahlbow, Hiroyoshi Sakurai, T. Motobayashi, Julien Gibelin, K. Boretzky, D. Calvet, David Steppenbeck, H. Törnqvist, Thomas Aumann, Nobuyuki Chiga, T. Koiwai, Kazuki Yoshida, Hideaki Otsu, Hirofumi Yamada, and J. Tscheuschner

Subjects
Physics, education.field_of_study, Proton, 010308 nuclear & particles physics, Nuclear Theory, Population, Nuclear shell model, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Pairing, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ground state, education
Abstract

Direct proton-knockout reactions of ^{55}Sc at ∼220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of ^{54}Ca were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the ^{55}Sc ground state with states in ^{54}Ca. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of ^{55}Sc, valence proton removals populated predominantly the ground state of ^{54}Ca. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.

Published
2021

7. First spectroscopic study of V63 at the N=40 island of inversion

Author

K. Moschner, David Steppenbeck, F. Browne, Jenny Lee, H. Törnqvist, Y. L. Sun, Kathrin Wimmer, Yuya Kubota, A. Gillibert, V. Panin, E. Sahin, L. X. Chung, D. Calvet, T. Isobe, Alessandra Corsi, Dóra Sohler, R.-B. Gerst, M. MacCormick, Yosuke Kondo, F. Château, Hideaki Otsu, P. Doornenbal, Hirofumi Yamada, N. Paul, V. Werner, Satoshi Takeuchi, M. L. Cortés, Masahiro Yasuda, D. M. Rossi, S. Franchoo, C. Lehr, W. Rodriguez, H. Baba, S. Y. Park, Z. Elekes, A. Giganon, Kazuyuki Ogata, Nobuyuki Chiga, Duo Yan, T. Lokotko, L. Zanetti, L. Stuhl, K. Yoneda, T. Koiwai, Takashi Nakamura, A. Delbart, Masaki Sasano, N. L. Achouri, S. Wang, B. D. Linh, Igor Gašparić, H. N. Liu, Yasuhiro Togano, V. Wagner, P. Koseoglou, F. Flavigny, J. M. Gheller, Tomohiro Uesaka, A. Obertelli, Zs. Dombrádi, Hiroyoshi Sakurai, T. Motobayashi, Julien Gibelin, Dong-Wook Kim, O. Aktas, V. Lapoux, K. Yoshida, M. M. Juhász, Kamila Sieja, Zaihong Yang, I. Murray, K. I. Hahn, T. Kobayashi, X. X. Xu, Si-Ge Chen, P. A. Söderström, Victor Vaquero, Thomas Aumann, and C. Hilaire

Subjects
Physics, 010308 nuclear & particles physics, Island of inversion, 0103 physical sciences, Geophysics, 010306 general physics, 01 natural sciences
Published
2021

8. 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

9. Experimental Study of $^{4}n$ by Directly Detecting the Decay Neutrons

Author

Atsumi Saito, Yohei Shimizu, H. Törnqvist, B. Monteagudo, T. Isobe, M. Caamaño, H. Scheit, S. Kiyotake, J. Tscheuschner, M. L. Cortés, F. M. Marqués, N. Fukuda, N. A. Orr, J. M. Gheller, A. Gillibert, A. Matta, K. Yoneda, L. Stuhl, Z. Elekes, I. Kuti, V. Wagner, M. Miwa, Z. Halász, A. Obertelli, S. Kim, A. Revel, L. Zanetti, N. L. Achouri, S. Takeuchi, F. Dufter, C. A. Douma, S. Masuoka, Stefanos Paschalis, R. Gernhäuser, S. Chen, Nobuyuki Chiga, S. Storck, T. Shimada, M.N. Harakeh, P. Koseoglou, T. Harada, B. Yang, M. Matsumoto, H. Takeda, D. S. Ahn, Yuya Kubota, H. Yamada, Yasuhiro Togano, A. Hirayama, Y. Yasuda, T. Fujino, D. M. Rossi, Nasser Kalantar-Nayestanaki, J. Tanaka, M. Böhmer, N. Inabe, Didier Beaumel, S. Park, Thomas Aumann, H. Baba, Tomohiro Uesaka, F. Schindler, J. Feng, Zaihong Yang, I. Murray, Julien Gibelin, K. Boretzky, S. W. Huang, B. Fernández-Domínguez, S. Reichert, Takashi Nakamura, Yu-xin Liu, K. Wimmer, Yukie Maeda, L. Yang, H. Sato, E. Tronchin, P. Doornenbal, Dmytro Symochko, D. Cortina, J. Kahlbow, S. Shimoura, H. Suzuki, Hideaki Otsu, M. Potlog, P. J. Li, J. Mayer, H. Miki, Masaki Sasano, Toshio Kobayashi, Z. Ge, D. Kim, Juzo Zenihiro, T. Tomai, I. Stefan, M. Parlog, H. Simon, V. Panin, Igor Gašparić, C. Lehr, Yosuke Kondo, C. Lenain, U. Forsberg, 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), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), Normandie Université (NU)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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), Research unit Nuclear & Hadron Physics, and Nuclear Energy

Subjects
Nuclear structure and force, tetraneutron, direct reactions, radioactive beams, Physics, Nuclear physics, 010308 nuclear & particles physics, 0103 physical sciences, Tetraneutron, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, 3. Good health
Abstract

The tetraneutron has attracted the attention of nuclear physicists during the past decades, but there is still no unambiguous confirmation of its existence or non-existence. A new experiment based on $$^{8}$$ He(p, 2p) $$^{7}$$ H{t+ $$^{4}n$$ } reaction, with direct detection of the four neutrons, has been carried out at RIBF, which can hopefully help to draw a definite conclusion on the tetraneutron system.

Published
2021

10. Angular momentum generation in nuclear fission

Author

B. Fornal, M. S. Yavahchova, C. Delafosse, A. Boso, V. Sánchez-Tembleque, K. Rezynkina, M. Lebois, K. Hauschild, T. Kröll, Muriel Fallot, P. Adsley, J. Ljungvall, Ł. W. Iskra, F. Ibrahim, E. Adamska, C. Henrich, A. Gottardo, Stephan Oberstedt, R. Chakma, C. Sürder, V. Guadilla, C. Porzio, P. H. Regan, J. Benito, A. Korgul, R. Lozeva, L. Le Meur, M. Piersa, P. Ivanov, V. Vedia, J. Nemer, B. Wasilewska, N. Jovančević, Y. Popovitch, W. Paulsen, C. Schmitt, N. Cieplicka-Oryńczak, R. B. Gerst, Sunniva Siem, G. Tocabens, P. A. Söderström, K. Belvedere, S. Courtin, S. Ziliani, R. Canavan, D. Gjestvang, L. Qi, D. Etasse, P. Koseoglou, G. Häfner, I. Matea, I. Homm, M. Heine, L. M. Fraile, T. Kurtukian-Nieto, Fabio Zeiser, P. Davies, D. Thisse, M. L. Cortés, A. Blazhev, S. Jazrawi, M. Bunce, A. Lopez-Martens, K. Miernik, Alejandro Algora, M. Rudigier, J. N. Wilson, N. Warr, J. Wiederhold, D. Verney, D. Ralet, M. Babo, L. Gaudefroy, G. Benzoni, S. Bottoni, S. Leoni, 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), University of Oslo (UiO), Department of Physics, University of Surrey, University of Surrey (UNIS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), 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), CEA, Bruyeres le Chatel, France, affiliation inconnue, University of Warsaw (UW), Facultat de Fisica [València] (UV), Universitat de València (UV), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Università degli Studi di Milano = University of Milan (UNIMI), Institut für Kernphysik der Universität zu Köln, Universität zu Köln = University of Cologne, National Physical Laboratory [Teddington] (NPL), Instytut Fizyki Jądrowej PAN (IFJ), Polskiej Akademii Nauk, 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), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), University of Manchester [Manchester], 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), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), 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), European Commission - Joint Research Centre [Geel] (JRC), 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), Horia Hulubei Natl Inst Phys & Nucl Engn IFIN HH, ELI NP Dept, Reactorului Str 30, Magurele 077125, Romania, Софийски университет = Sofia University, Technische Universität Darmstadt (TU Darmstadt), Universidad Complutense de Madrid [Madrid] (UCM), Università degli studi di Milano [Milano], Universität zu Köln, Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes - Faculté des Sciences et des Techniques, 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), Technical University Darmstadt (TU), 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), University of Sofia, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Università degli Studi di Milano [Milano] (UNIMI), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Direction des Applications Militaires (DAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, [PHYS]Physics [physics], Angular momentum, Multidisciplinary, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Spins, 010308 nuclear & particles physics, Fission, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Nuclear fission, 0103 physical sciences, Atomic nucleus, Nuclear Experiment, 010306 general physics, Nucleon, Excitation, ComputingMilieux_MISCELLANEOUS, Spin-½
Abstract

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4–12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18. γ-ray spectroscopy experiments on the origin of spin in the products of nuclear fission of spin-zero nuclei suggest that the fission fragments acquire their spin after scission, rather than before.

Published
2021

11. The GALILEO γ-ray array at the Legnaro National Laboratories

Author

R. Menegazzo, I. Zanon, F. Veronese, D.A. Testov, J. Ha, N. Bez, B. Million, G. Pasqualato, Alberto Pullia, M. Biasotto, L. Ramina, S. Bottoni, C. A. Ur, M. L. Cortés, D. Mengoni, S. Coelli, G. Gosta, C. Fanin, M. Siciliano, A. Saltarelli, D. Bazzacco, D. Tomasella, J. J. Valiente-Dobón, S. Leoni, M. Romanato, S. Ventura, A. Gadea, N. Toniolo, Marco Bellato, Diego Barrientos, S. Brambilla, D. Brugnara, R.M. Pérez-Vidal, F. Recchia, F. C. L. Crespi, F.J. Egea, S. Lunardi, S. Capra, M. Rebeschini, S. Fantinel, G. Jaworski, A. Bracco, M. Gulmini, G. Rampazzo, M. Scarcioffolo, N. Blasi, J. Pellumaj, S. Pigliapoco, G. Benzoni, V. Volpe, P. Cocconi, A. Boso, O. Wieland, K. Hadyńska-Klȩk, E.R. Gamba, A. Capsoni, A. Gambalonga, E. Viscione, F. Camera, G. de Angelis, A. Nannini, Roberto Isocrate, C. Boiano, A. Illana, M. Rocchini, G. Zhang, A. Gottardo, A. Goasduff, C. Gesmundo, P. R. John, N. Marchini, S. Ziliani, K. Rezynkina, D. R. Napoli, E. Gregor, A. Gozzelino, D. Rosso, M. Rampazzo, V. Modamio, M. Polettini, M. Magalini, F. Tomasi, S. M. Lenzi, and C. Porzio

Subjects
Physics, Nuclear and High Energy Physics, Silicon, business.industry, Instrumentation, High-resolution γ-ray spectroscopy, Detector, Neutron, DAQ, Electronics, HPGe, Semiconductor detector, Optics, Data acquisition, Galileo (vibration training), business, Hpge detector
Abstract

GALILEO, a new 4 π high-resolution γ -detection array, based on HPGe detectors, has been developed and installed at the Legnaro National Laboratories. The GALILEO array greatly benefits from a fully-digital read-out chain, customized DAQ, and a variety of complementary detectors to improve the resolving power by the detection of particles, ions or high-energy γ -ray transitions. In this work, a full description of the array, including electronics and DAQ, is presented together with its complementary instrumentation.

Published
2021

12. First spectroscopic study of $^{51}$Ar by the (p,2p) reaction

Author

Zs. Dombradi, S. Y. Park, T. Isobe, F. Browne, K. Moschner, Thomas Aumann, R.-B. Gerst, F. Château, Kathrin Wimmer, X. X. Xu, Z. Elekes, L. Zanetti, Hideaki Otsu, B. D. Linh, Hirofumi Yamada, Si-Ge Chen, P. A. Söderström, Yutaka Utsuno, Igor Gašparić, H. N. Liu, Jenny Lee, Zaihong Yang, I. Murray, Yasuhiro Togano, F. Flavigny, K. I. Hahn, L. Stuhl, Yuya Kubota, V. Wagner, Tomohiro Uesaka, A. Giganon, D. Kim, M. MacCormick, C. Lehr, V. Panin, L. X. Chung, P. Koseoglou, T. Lokotko, Y.L. Sun, E. Sahin, K. Yoneda, Victor Vaquero, M. L. Cortés, Takashi Nakamura, S. Franchoo, P. Doornenbal, Satoshi Takeuchi, Masahiro Yasuda, O. Aktas, A. Gillibert, V. Lapoux, Nobuyuki Chiga, Takaharu Otsuka, T. Koiwai, Hiroyoshi Sakurai, T. Motobayashi, M. M. Juhász, Kazuki Yoshida, David Steppenbeck, Julien Gibelin, H. Törnqvist, Toshio Kobayashi, Kazuyuki Ogata, W. Rodriguez, N. L. Achouri, C. Hilaire, S. Wang, Donghang Yan, N. Paul, A. Obertelli, J. M. Gheller, Yosuke Kondo, V. Werner, D. Calvet, D. M. Rossi, Masaki Sasano, H. Baba, D. Sohler, A. Corsi, A. Delbart, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), 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), 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), 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), RIKEN Nishina Center for Accelerator-Based Science, European Research Council, European Commission, Helmholtz International Center for FAIR, German Research Foundation, Alexander von Humboldt Foundation, Ministry of Science and Technology of Vietnam, Government of South Korea, Agencia Estatal de Investigación (España), Federal Ministry of Education and Research (Germany), Helmholtz Graduate School for Hadron and Ion Research, and National Research, Development and Innovation Office (Hungary)

Subjects
Nuclear and High Energy Physics, Shell closure, γ -ray spectroscopy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 0103 physical sciences, Bound state, nuclear shell model, proton knock-out reaction, gamma-ray spectroscopy, invariant-mass method, radioactive beams, Invariant mass, Neutron, ddc:530, Nuclear structure, 010306 general physics, Spectroscopy, Physics, Valence (chemistry), Proton knock-out reaction, 010308 nuclear & particles physics, Invariant mass method, Isotopes of argon, lcsh:QC1-999, Excited state, γ-ray spectroscopy, Atomic physics, lcsh:Physics
Abstract

8 pags., 4 figs., 3 tabs., The nuclear structure of 51Ar, an uncharted territory so far, was studied by the (p,2p) reaction using γ-ray spectroscopy for the bound states and the invariant mass method for the unbound states. Two peaks were detected in the γ-ray spectrum and six peaks were observed in the 50Ar+n relative energy spectrum. Comparing the results to our shell-model calculations, two bound and six unbound states were established. Three of the unbound states could only be placed tentatively due to the low number of counts in the relative energy spectrum of events associated with the decay through the first excited state of 50Ar. The low cross sections populating the two bound states of 51Ar could be interpreted as a clear signature for the presence of significant subshell closures at neutron numbers 32 and 34 in argon isotopes. It was also revealed that due to the two valence holes, unbound collective states coexist with individual-particle states in 51Ar., We are very grateful to the RIKEN Nishina Center accelerator staff for providing the stable beam and to the BigRIPS team for the smooth operation of the secondary beams. The development of the MINOS device has been supported by the European Research Council through the ERC Grant No. MINOS-258567. F. B. was supported by the RIKEN Special Postdoctoral Researcher Program. K. O. acknowledges the support by Grant-in-Aid for Scientific Research JP16K05352. Y. U. acknowledges the support by Grant-in-Aid for Scientific Research 20K03981. Y. L. S. acknowledges the support of Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2015-705023) from the European Union and the support from the Helmholtz International Center for FAIR. H. N. L. acknowledges the support from the Enhanced Eurotalents program (PCOFUND-GA-2013-600382) co-funded by CEA and the European Union. T. A., C. L., D. R., H. T., V. W., L. Z., H. N. L., V. W. and A. O. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Project No. 279384907-SFB 1245. R. B. G. acknowledges the support from the DFG under Grant No. BL 1513/1-1. Y. L. S. and A. O. acknowledge the support from the Alexander von Humboldt Foundation. B. D. L. and L. X. C. acknowledge the support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. I. G. has been supported by HIC for FAIR and HRZZ under project No. 1257 and 7194. K. I. H., D. K. and S. Y. P. acknowledge the support from the NRF grant funded by the Korea government (No. 2017R1A2B2012382 and 2019M7A1A1033186). F. B. acknowledge the support from the RIKEN Special Postdoctoral Researcher Program. D. S. and Z. E. were supported by projects No. GINOP-2.3.3-15-2016-00034 and No. K128947. V. V. acknowledges support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. V. W. and P. K. acknowledge the support from BMBF grants 05P15RDFN1 and 05P19RDFN1. P. K. acknowledges support from HGS-HIRe. This work was also supported by NKFIH (114454).

Published
2021

13. 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

14. Manifestation of the Berry phase in the atomic nucleus 213Pb

Author

S. Klupp, A. Algora, Roberto Menegazzo, D. Mengoni, F. Naqvi, J. J. Valiente-Dobón, S. Pietri, T. Habermann, J. Benlliure, Branislav Sitar, Alison Bruce, A. Bracco, P. Van Isacker, N. Kurz, Andrea Corsi, E. Sahin, Dirk Rudolph, Imrich Szarka, Helmut Weick, Zs. Podolyák, J. Gerl, J. Grebosz, Davinder Siwal, S. K. Mandal, S. Leoni, T. Engert, D. Bazzacco, A. Prochazka, M. Górska, F. Recchia, S. Lunardi, D. R. Napoli, Hans Geissel, P. Boutachkov, A. Gottardo, F. Camera, Enrique Casarejos, I. Kojouharov, P. H. Regan, E. Gregor, Oliver Wieland, H. J. Wollersheim, A. Sharma, G. de Angelis, C. Nociforo, F. C. L. Crespi, A. Goasduff, C. Domingo-Pardo, A. I. Morales, M. Pfützner, B. Million, G. Benzoni, M. L. Cortés, Philip M Walker, C. A. Ur, Peter Strmen, H. Schaffner, A. Gadea, Maria Doncel, N. Goel, S. M. Lenzi, 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), 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
Nuclear and High Energy Physics, Angular momentum, nucl-th, Nuclear Theory, isomeric decays, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 01 natural sciences, Nuclear Theory (nucl-th), 0103 physical sciences, Subatomic Physics, Nuclear Physics - Experiment, ddc:530, 22 Física, Nuclear Experiment (nucl-ex), 010306 general physics, Spectroscopy, Nuclear Experiment, Physics, Isotope, 010308 nuclear & particles physics, 2207 Física Atómica y Nuclear, Quantum number, lcsh:QC1-999, relativistic projectile fragmentation, ddc, Geometric phase, gamma-ray spectroscopy, Nuclear Physics - Theory, Atomic nucleus, Atomic number, Atomic physics, Nucleon, lcsh:Physics
Abstract

Physics letters / B 816, 136183 (2021). doi:10.1016/j.physletb.2021.136183, Published by North-Holland Publ., Amsterdam

Published
2021

15. Prompt and delayed γ spectroscopy of neutron-rich Kr94 and observation of a new isomer

Author

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

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Yrast, Nuclear Theory, 01 natural sciences, 7. Clean energy, Atomic orbital, Nuclear fission, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Spectroscopy
Abstract

Prompt and delayed γ -ray spectroscopy of the neutron-rich 94 Kr was performed, as part of the fission campaign at the ALTO facility of the IPN Orsay, using the fast-neutron-induced fission reaction 238 U ( n , f ) in combination with the ν -Ball array, a novel hybrid γ spectrometer for energy and lifetime measurements. Several new yrast and nonyrast transitions were observed for the first time, extending the previously known level scheme. Additionally, we report on the observation of a new short-lived isomer at 3444 keV with a half-life of 32(3) ns. The analysis of the Nilsson orbitals obtained from Gogny cranked Hartree-Fock-Bogoliubov calculations suggests a ( 9 − ) spin and an oblate deformation for this isomer corresponding to a two-quasineutron state, indicating an isomeric structure very similar to that of the neighboring isotones 96 Sr and 92 Se

Published
2020

16. N=32 shell closure below calcium: Low-lying structure of Ar50

Author

Nobuyuki Chiga, K. Moschner, T. Koiwai, Hiroyoshi Sakurai, V. Lapoux, A. Gillibert, Yutaka Utsuno, D. Calvet, T. Isobe, Kathrin Wimmer, T. Motobayashi, Jenny Lee, Achim Schwenk, H. Toernqvist, Yuya Kubota, Victor Vaquero, R.-B. Gerst, F. Château, W. Rodriguez, N. Shimizu, B. D. Linh, D. M. Rossi, Masahiro Yasuda, Tomohiro Uesaka, Hideaki Otsu, Igor Gašparić, H. N. Liu, V. Panin, H. Baba, Kazuyuki Ogata, L. X. Chung, S. Y. Park, Julien Gibelin, Hirofumi Yamada, K. Yoshida, C. Lehr, Duo Yan, L. Achouri, Zaihong Yang, L. Stuhl, A. Giganon, I. Murray, S. Wang, N. Paul, L. Zanetti, E. Sahin, Y. L. Sun, J. Simonis, A. Obertelli, K. Yoneda, C. Hilaire, K. I. Hahn, V. Werner, David Steppenbeck, Jason D. Holt, P. Doornenbal, A. Delbart, M. MacCormick, P. Koseoglou, J. M. Gheller, Alessandra Corsi, Thomas Aumann, Masaki Sasano, Dóra Sohler, Satoshi Takeuchi, M. L. Cortés, S. Franchoo, T. Kobayashi, F. Flavigny, X. X. Xu, Si-Ge Chen, P. A. Söderström, Dong-Wook Kim, F. Browne, O. Aktas, Yosuke Kondo, Yasuhiro Togano, T. Lokotko, Takashi Nakamura, Javier Fernandez Menendez, and V. Wagner

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Closure (topology), Shell (structure), Calcium low, 010306 general physics, 01 natural sciences, Molecular physics
Published
2020

17. Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei

Author

Megumi Niikura, K. Yoneda, Tomohiro Uesaka, T. Miyazaki, J.-Y. Roussé, A. Jungclaus, I. G. Stefan, Masaki Sasano, A. Gillibert, Jian Liu, Hiroyoshi Sakurai, David Steppenbeck, Zs. Dombradi, K. Moschner, M. Gómez-Ramos, Satoshi Takeuchi, D. Calvet, T. Isobe, Shunji Nishimura, T. Saito, V. Lapoux, H. Wang, T. Motobayashi, L. Olivier, R. Lozeva, A. Gottardo, S. Franchoo, C. Péron, H. Baba, Jinguang Wu, G. Authelet, A. Delbart, A. Blazhev, J. M. Gheller, Hideaki Otsu, F. Château, Masafumi Matsushita, Zs. Vajta, Zena Patel, Victor Vaquero, Kathrin Wimmer, M. L. Cortés, K. Matsui, Shuichi Ota, C. Santamaria, E. C. Pollacco, M. Dewald, Alessandra Corsi, F. Browne, C. R. Nita, M. Rudigier, Z. Korkulu, Jenny Lee, Yoshiaki Shiga, K. Hadynska-Klek, S. Nagamine, Satoru Momiyama, A. Frotscher, T. Arici, Ryo Taniuchi, Noritaka Shimizu, C. R. Nobs, Toshiyuki Sumikama, Alison Bruce, C. Louchart, E. Sahin, Toshiaki Ando, Zhenci Xu, F. Giacoppo, Y. Kubota, L. X. Chung, B. D. Linh, P. Doornenbal, F. Flavigny, A. Giganon, N. Paul, C. M. Shand, Noritsugu Nakatsuka, Zi Hong Liu, V. Werner, M. Górska, Si-Ge Chen, P. A. Söderström, D. Suzuki, M. Lettmann, R. Orlandi, C. Lizarazo, A. Obertelli, Raymond J. Carroll, Bing Ding, Zs. Podolyák, Shoko Koyama, and Alan Peyaud

Subjects
Physics, Hydrogen, Proton, Projectile, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, 01 natural sciences, Coincidence, Nuclear physics, medicine.anatomical_structure, chemistry, MINOS, 0103 physical sciences, medicine, Neutron, Nuclear Experiment, 010306 general physics, Nucleon, Nucleus
Abstract

Twenty-one two-proton knockout (p; 3p) cross sections from neutron-rich nuclei at ~ 250 MeV/nucleon were measured. For the first time, the angular distribution of the three emitted protons were measured in coincidence with the tracker and hydrogen target MINOS, demonstrating that the (p; 3p) kinematics is consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p; 3p) over (p; 2p) inclusive cross sections follow the trend of other many-proton (neutron) removal reactions, further reinforcing the sequential nature of (p; 3p) in neutron-rich nuclei.

Published
2020

18. Metastable States of Se92,94 : Identification of an Oblate K Isomer of Se94 and the Ground-State Shape Transition between N=58 and 60

Author

L. Olivier, I. Kojouharov, G. Authelet, J. M. Gheller, V. Lapoux, Jenny Lee, J.-Y. Roussé, J. Gerl, C. Lizarazo, N. Paul, Noritsugu Nakatsuka, Hiroyoshi Sakurai, H. Schaffner, P. M. Walker, Zi Hong Liu, V. Werner, David Steppenbeck, T. Motobayashi, A. Blazhev, P. Doornenbal, Shunji Nishimura, I. Stefan, M. L. Cortés, T. Arici, J. J. Liu, Tomás R. Rodríguez, Alison Bruce, A. Giganon, C. Santamaria, F. Château, Megumi Niikura, Zhengyu Xu, F. Browne, Tomohiro Uesaka, M. Rudigier, C. R. Niţă, P. A. Söderström, Zena Patel, T. Saito, N. Kurz, M. Górska, S. Franchoo, A. Gillibert, G. X. Dong, A. Gottardo, C. M. Shand, Satoru Momiyama, L. X. Chung, C. R. Nobs, B. D. Linh, S. Nagamine, Ryo Taniuchi, A. Obertelli, M. Dewald, K. Moschner, Kathrin Wimmer, H. Baba, R. J. Caroll, D. Calvet, F. Flavigny, Bing Ding, Zs. Podolyák, Furong Xu, Toshiaki Ando, Si-Ge Chen, Victor Vaquero, M. Lettmann, A. Corsi, Norbert Pietralla, and A. Delbart

Subjects
Physics, 010308 nuclear & particles physics, General Physics and Astronomy, chemistry.chemical_element, Germanium, 01 natural sciences, Hafnium, medicine.anatomical_structure, chemistry, Atomic orbital, Metastability, 0103 physical sciences, Physics::Atomic and Molecular Clusters, medicine, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Spectroscopy, Nucleus
Abstract

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.

Published
2020

19. Metastable States of ^{92,94}Se: Identification of an Oblate K Isomer of ^{94}Se and the Ground-State Shape Transition between N=58 and 60

Author

C, Lizarazo, P-A, Söderström, V, Werner, N, Pietralla, P M, Walker, G X, Dong, F R, Xu, T R, Rodríguez, F, Browne, P, Doornenbal, S, Nishimura, C R, Niţă, A, Obertelli, T, Ando, T, Arici, G, Authelet, H, Baba, A, Blazhev, A M, Bruce, D, Calvet, R J, Caroll, F, Château, S, Chen, L X, Chung, A, Corsi, M L, Cortés, A, Delbart, M, Dewald, B, Ding, F, Flavigny, S, Franchoo, J, Gerl, J-M, Gheller, A, Giganon, A, Gillibert, M, Górska, A, Gottardo, I, Kojouharov, N, Kurz, V, Lapoux, J, Lee, M, Lettmann, B D, Linh, J J, Liu, Z, Liu, S, Momiyama, K, Moschner, T, Motobayashi, S, Nagamine, N, Nakatsuka, M, Niikura, C, Nobs, L, Olivier, Z, Patel, N, Paul, Zs, Podolyák, J-Y, Roussé, M, Rudigier, T Y, Saito, H, Sakurai, C, Santamaria, H, Schaffner, C, Shand, I, Stefan, D, Steppenbeck, R, Taniuchi, T, Uesaka, V, Vaquero, K, Wimmer, and Z, Xu

Abstract

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.

Published
2020

20. Low-lying electric dipole gamma-continuum for the unstable Fe-62,64 nuclei : Strength evolution with neutron number

Author

Eric Clément, B. Birkenbach, A. I. Morales, D. Bazzacco, H. J. Wollersheim, J. J. Valiente-Dobón, D. M. Cullen, L. J. Harkness-Brennan, M. Kmiecik, Alberto Pullia, C. Domingo-Pardo, Luis Sarmiento, C. Nociforo, N. Goel, B. Bruyneel, G. Rainovski, M.D. Salsac, S. Pietri, Begoña Quintana, J. Simpson, Pavel Golubev, T. Habermann, Johan Nyberg, R. Menegazzo, S. Leoni, M. Reese, V. Yu. Ponomarev, A. Maj, T. Arici, A. Gottardo, N. Kurz, M. Górska, S. Brambilla, I. Kojouharov, E. Merchan, M. L. Cortés, Stefano Riboldi, Enrique Sanchis, N. Lalović, Vicente González, R. Avigo, Norbert Pietralla, P. Reiter, F. Camera, M. Labiche, Zs. Podolyák, J. Gerl, D. Ralet, F. Ameil, Andreas Görgen, A. Gadea, A. Bracco, A. Jungclaus, G. Benzoni, O. Stezowski, Dirk Rudolph, D. Curien, J. Eberth, H. C. Boston, S. Bottoni, W. Korten, F. C. L. Crespi, N. Blasi, H. Schaffner, D. Mengoni, M. Lettmann, G. Duchêne, Diego Barrientos, P. H. Regan, F. Didierjean, M. Ciemala, P. Bednarczyk, G. Guastalla, B. Million, E. Gregor, Oliver Wieland, F. Recchia, D. R. Napoli, A. Atac, 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), 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 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), Institut de Physique Nucléaire de Lyon (IPNL), 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), Istituto Nazionale di Fisica Nucleare, Science and Technology Facilities Council (UK), Swedish Research Council, Federal Ministry of Education and Research (Germany), European Commission, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), 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 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), Université Claude Bernard Lyon 1 (UCBL), and 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)

Subjects
Nuclear and High Energy Physics, Phonon, Astrophysics::High Energy Astrophysical Phenomena, Binding energy, Nuclear Theory, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 64Fe, Dipole excitation around neutron threshold, 62Fe, Subatomär fysik, 0103 physical sciences, Subatomic Physics, ddc:530, Neutron, Nuclear Physics - Experiment, Nuclear structure, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, 62 Fe, Fe, 64, 64 Fe, lcsh:QC1-999, Dipole, Fe-64, Neutron number, Fe-62, AGATA, Atomic physics, lcsh:Physics
Abstract

6 pags., 4 figs., The γ-ray emission from the nuclei Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1 states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy., This work was partially supported by INFN (Italy) and STFC (UK), the Swedish Research Council (Vetenskapsrådet, VR 2010-147, 2011-5253, and 2016-3969), BMBF NuSTAR-AGATA 05P18RDFN9 and BMBF NuSTAR 05P18RDFN1. The project was co-funded by the European Commission under the 7th Framework Program for RTD (2007-2013) under the Capacities Program (Contract Number 262010, ENSAR). This work was par-tially supported by the Ministry of Science, and Generalitat Valenciana, Spain, under the Grants SEV-2014-0398, FPA2017-84756-C4, PROMETEO/2019/005 and by the EU FEDER funds.

Published
2020

21. Benchmarking the PreSPEC@GSI experiment for Coulex-multipolarimetry on the $\pi (p_{3/2})\rightarrow \pi (p_{1/2})$ spin-flip transition in $^{85}$Br

Author

Diego Barrientos, M. Labiche, L. Grassi, J. Eberth, Claes Fahlander, V. Modamio, I. Kojouharov, B. Birkenbach, O. Möller, H. Egger, F. C. L. Crespi, P. Désesquelles, C. Domingo-Pardo, S. Afara, W. Korten, A. Bracco, B. S. Nara Singh, D. M. Cullen, Enrique Sanchis, M. Lettmann, Pavel Golubev, Oliver Wieland, J. Gerl, B. Bruyneel, G. Rainovski, Dirk Rudolph, A. Maj, Norbert Pietralla, A. Blazhev, P. R. John, A. Gottardo, D. Curien, P. Bednarczyk, B. Million, Luis Sarmiento, T. Arici, Pushpendra Singh, S. Aydin, E. Merchan, P. Reiter, F. Ameil, S. Pietri, J. Simpson, Eric Clément, J. Jolie, C. Stahl, K. A. Gladnishki, K. Moschner, Herbert Hess, A. J. Boston, D. Ralet, M. L. Cortés, N. Lalović, C. Louchart-Henning, M. A. Bentley, D. S. Judson, H. Schaffner, J. J. Valiente-Dobón, P. Boutachkov, Roberto Menegazzo, D. Mengoni, M. Reese, V. Werner, G. Duchêne, L. J. Harkness-Brennan, G. Benzoni, D. R. Napoli, Vicente González, F. Didierjean, Zs. Podolyák, T. Möller, C. Lizarazo, P. Napiralla, M. Górska, T. Habermann, D. G. Jenkins, 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), 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 Pluridisciplinaire Hubert Curien (IPHC), 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 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), Institut de Physique Nucléaire d'Orsay (IPNO), 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 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 Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Transition strength, 0103 physical sciences, Nuclear fusion, AGATA, Spin-flip, 010306 general physics, Beam (structure)
Abstract

International audience; A first performance test of the Coulomb excitation multipolarimetry (Coulex-multipolarimetry) method is presented. It is based on a $^{85}\hbox {Br}\,\pi p_{3/2}\rightarrow \pi p_{1/2}$ spin-flip experiment performed as part of the PreSPEC-AGATA campaign at the GSI Helmholtzzentrum für Schwerionenforschung (GSI). Via determination of background levels around the expected $^{85}\hbox {Br}$ excitations as well as measured $^{197}\hbox {Au}$ excitations, an upper limit for the M1 transition strength of the $1/2_1^-\rightarrow 3/2_\text {g.s.}^-$ transition in $^{85}\hbox {Br}$ and a lower beam time limit for upcoming experimental campaigns utilizing Coulex-multipolarimetry have been inferred. The impact of the use of AGATA in its anticipated $1\pi $ configuration on these estimates is deduced via Geant4 simulations.

Published
2020

22. Lifetime measurement of the $^{26}0 g.s.$ at SAMURAI

Author

Hiroyuki Takeda, Takashi Nakamura, Hideaki Otsu, Olivier Sorlin, Masaki Sasano, Zaihong Yang, I. Murray, D. M. Rossi, Yuya Kubota, A. Hirayama, Thomas Aumann, Makoto Yasuda, K. I. Hahn, L. Atar, H. Baba, Sonja Storck, S. Choi, Z. Halász, Yohei Shimizu, C. Caesar, L. Stuhl, H. Scheit, C. Lehr, Nobuyuki Chiga, Yasuhiro Togano, Thomas Nilsson, Hans Törnqvist, Z. Elekes, D. Körper, M. Matsumoto, M. L. Cortés, Naohito Inabe, Yosuke Kondo, T. Murakami, D. S. Ahn, K. Yoneda, Marina Petri, Atsumi Saito, T. Tomai, Tomohiro Uesaka, M. Parlog, Simon Lindberg, V. Panin, M. Marques, D. Cortina-Gil, T. Isobe, H. Chae, S. K. Kim, István Kuti, Jongwon Hwang, Herbert A. Simon, P. Schrock, Naoki Fukuda, T. Kobayashi, J. Kahlbow, H. Suzuki, D. Sohler, H. Yamada, I. Syndikus, K. Boretzky, Q. Deshayes, P. Doornenbal, I. Gaparic, Stefanos Paschalis, 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), 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), SAMURAI20, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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, Superconductivity, History, Radionuclide, Spectrum analyzer, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 010305 fluids & plasmas, Computer Science Applications, Education, Nuclear physics, Stack (abstract data type), 0103 physical sciences, Physics::Accelerator Physics, ddc:530, Neutron, Radio isotopes, 010306 general physics, Ground state, Nuclear Experiment, Beam (structure)
Abstract

27th International Nuclear Physics Conference, INPC2019, Glasgow, United Kingdom, 29 Jul 2019 - 2 Aug 2019; Journal of physics / Conference series 1643(1), 012106 (2020). doi:10.1088/1742-6596/1643/1/012106, Published by IOP Publ., Bristol

Published
2020
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23. Two-Neutron Halo is Unveiled in $^{29}F$

Author

M. Holl, Naoki Fukuda, Hiroyuki Takeda, Stefanos Paschalis, I. Murray, H. Baba, S. J. Novario, K. Itahashi, David Steppenbeck, Hooi Jin Ong, F. Browne, W. G. Jiang, Maya Takechi, Hans Geissel, K. H. Behr, Ryo Taniuchi, P. Doornenbal, A. Estrade, Hiroyoshi Sakurai, Naohito Iwasa, M. L. Cortés, P. Schrock, Y.K. Tanaka, Kenichi Yoshida, Satoshi Takeuchi, A. Prochazka, Hiroshi Suzuki, Toshio Suzuki, Satoru Momiyama, Wataru Horiuchi, Takaharu Otsuka, Gaute Hagen, Naofumi Tsunoda, Si-Ge Chen, R. Kanungo, S. Bagchi, Gustav R. Jansen, Satbir Kaur, Daisuke Suzuki, Takashi Nakamura, C. Scheidenberger, Y. Shimizu, S. Y. Matsumoto, Thomas Papenbrock, A. O. Macchiavelli, D. S. Ahn, Kathrin Wimmer, 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, Nuclear Theory, Field (physics), [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Strong interaction, SHELL model, Shell (structure), FOS: Physical sciences, General Physics and Astronomy, Radius, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear Theory (nucl-th), Neutron number, 0103 physical sciences, Neutron, Halo, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Nuclear Experiment, Nuclear Physics
Abstract

We report the measurement of reaction cross sections ($\sigma_R^{\rm ex}$) of $^{27,29}$F with a carbon target at RIKEN. The unexpectedly large $\sigma_R^{\rm ex}$ and derived matter radius identify $^{29}$F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the $2p_{3/2}$ orbital, thereby vanishing the shell closure associated with the neutron number $N = 20$. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of $^{27}$F but are challenged for $^{29}$F., Comment: 8 pages, 4 figures

Published
2020

24. Experimental study of 4 n with 8He(p,2p) reaction

Author

M. Böhmer, Masaki Sasano, S. Reichert, Naohito Inabe, S. Chen, T. Shimada, M. Matsumoto, Susumu Shimoura, I. Stefan, J. Kahlbow, N. Kalantar-Nayestanaki, T. Harada, D. Symochko, István Kuti, S. W. Huang, D. Cortina, Tomohiro Uesaka, Z. Ge, N. L. Achouri, Yosuke Kondo, Hiroyuki Takeda, K. Yoneda, B. Fernández-Domínguez, U. Forsberg, Z. Elekes, Roman Gernhäuser, Y. Yasuda, H. Suzuki, Yohei Shimizu, D. Beaumel, D. Kim, C. A. Douma, Yukie Maeda, A. Hirayama, J. M. Gheller, Heiko Scheit, F. Dufter, T. Elidiano, Yasuhiro Togano, M. L. Cortés, M. Potlog, Nobuyuki Chiga, P. J. Li, Juzo Zenihiro, B. Yang, T. Isobe, M. Caamaño, Thomas Aumann, H. T. Törnqvsit, A. Gillibert, D. S. Ahn, F. Schindler, M.N. Harakeh, J. Feng, J. Tscheuschner, S. Kim, Atsumi Saito, L. Zanetti, P. Koseoglou, V. Wagner, M. Parlog, B. M. Godoy, N. Orr, Takashi Nakamura, Yu-xin Liu, J. Mayer, A. Obertelli, Yuya Kubota, Hideaki Otsu, S. Storck, S. Masuoka, K. Boretzky, Kathrin Wimmer, H. Miki, T. Tomai, F. M. Marqués, V. Panin, P. Doornenbal, Stefanos Paschalis, L. Yang, Satoshi Takeuchi, M. A. Knösel, Igor Gašparić, T. Kobayashi, C. Lehr, H. Yang, C. Lenain, M. Miwa, Z. Halász, A. Revel, H. Sato, T. Fujino, D. M. Rossi, H. Baba, S. Park, I. Murray, L. Stuhl, H. Yamada, J. Gibelin, J. Tanaka, Naoki Fukuda, RIKEN Nishina Center for Accelerator-Based Science, German Research Foundation, Federal Ministry of Education and Research (Germany), 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), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), Normandie Université (NU)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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, Paper, History, 010308 nuclear & particles physics, tetraneutron, nuclear force, proton knock-out, radioactive beams, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computer Science Applications, Education, ddc, Nuclear physics, 0103 physical sciences, Tetraneutron, Neutron, ddc:530, 010306 general physics
Abstract

7 pags., 3 figs. -- 27th International Nuclear Physics Conference (INPC2019), The tetraneutron has attracted the attention of nuclear physicists during the past decades, but there is still no unambiguous confirmation of its existence or nonexistence. A new experiment based on 8 He(p,2p)7H{t+4n} reaction, with direct detection of the four neutrons, has been carried out at RIBF, which can hopefully help to draw a definite conclusion on the tetraneutron system., We acknowledge the support of the RIBF accelerator staff and the BigRIPS team for providing the high-quality beam. Z. H. Yang acknowledges the financial support from the Foreign Postdoctoral Researcher program of RIKEN. T. Aumann acknowledges the support by DFG via SFB 1245. P. Koseoglou acknowledges the support from BMBF (NUSTAR.DA grant No.05P 15RDFN1).

Published
2020

25. Shell evolution beyond Z = 28 and N = 50: Spectroscopy of 81,82,83,84 Zn

Author

L. Olivier, K. Moschner, Kathrin Wimmer, E. C. Pollacco, A. Gillibert, C. R. Nita, C. M. Shand, J.-Y. Roussé, Satoru Momiyama, M. Lettmann, Jian Liu, A. Jungclaus, Hideaki Otsu, Z. Korkulu, Ryo Taniuchi, C. Péron, David Steppenbeck, A. Blazhev, Tsuyoshi Miyazaki, G. Authelet, K. Matsui, Satoshi Takeuchi, A. Château, A. Obertelli, F. Nowacki, S. Franchoo, Kamila Sieja, Toshiaki Ando, J. M. Gheller, Alan Peyaud, Jin Wu, L. X. Chung, Shuichi Ota, C. R. Nobs, B. D. Linh, Zs. Vajta, Y. Kubota, Megumi Niikura, M. Rudigier, I. Stefan, H. Wang, R. Orlandi, J. A. Tostevin, Takaharu Otsuka, Si-Ge Chen, P. A. Söderström, Tomohiro Uesaka, C. Lizarazo, S. Nishimura, Zs. Dombradi, Toshiyuki Sumikama, K. Hadynska-Klek, M. Nagamine, Yusuke Tsunoda, T. Isobe, E. Sahin, C. Louchart, Hiroyoshi Sakurai, V. Lapoux, C. Santamaria, T. Motobayashi, Victor Vaquero, F. Giacoppo, T. Arici, A. Corsi, Zena Patel, P. Doornenbal, Masafumi Matsushita, A. Delbart, P. H. Regan, M. Dewald, Zsolt Podolyak, A. Giganon, A. Gottardo, Jenny Lee, F. Flavigny, M. Górska, N. Paul, Noritsugu Nakatsuka, M. L. Cortés, Zi Hong Liu, V. Werner, Raymond J. Carroll, Daisuke Suzuki, D. Calvet, M. Sasano, Bing Ding, Shoko Koyama, Zhengyu Xu, T. Saito, Alison Bruce, R. Lozeva, K. Yoneda, F. Browne, H. Baba, Yoshiaki Shiga, SCOAP, RIKEN Nishina Center for Accelerator-Based Science, Science and Technology Facilities Council (UK), European Commission, European Research Council, Vietnam Academy of Science and Technology, Federal Ministry of Education and Research (Germany), Ministerio de Economía y Competitividad (España), 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)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université de Strasbourg (UNISTRA)-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, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, SHELL model, Analytical chemistry, Shell (structure), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, lcsh:QC1-999, Atomic orbital, Neutron number, 0103 physical sciences, ddc:530, Atomic physics, 010306 general physics, Spectroscopy, lcsh:Physics
Abstract

C.M. Shand et al. -- 6 pags., 3 figs., tab. --Open Access funded by Creative Commons Atribution Licence 4.0, We report on the measurement of new low-lying states in the neutron-rich Zn nuclei via in-beam γ-ray spectroscopy. These include the 4 →2 transition in Zn, the 2 →0 and 4 →2 transitions in Zn, and low-lying states in Zn were observed for the first time. The reduced E(2 ) energies and increased E(4 )/E(2 ) ratios at N=52, 54 compared to those in Zn attest that the magicity is confined to the neutron number N=50 only. The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations. The newly observed 2 and 4 levels in Zn suggest the onset of deformation towards heavier Zn isotopes, which has been incorporated by taking into account the upper sdg orbitals in the Ni78-II and the PFSDG-U models., All UK authors are supported by the Science and Technology Facilities Council (STFC). The development of MINOS and the core MINOS team have been supported by the European Research Council through the ERC Grant No. MINOS-258567. A. Jungclaus was supported by the Spanish Ministerio de Economía y Competitividad under contract FPA2014-57196-C5-4-P. Authors from Cologne were supported by German BMBF Grant No. 05P15PKFNA. Authors from TU Darmstadt were supported by German BMBF Grant No. 05P12RDFN8 and 05P15RDFN1. L.X. Chung and B.D. Linh would like to acknowledge Vietnam Ministry of Science and Technology for the support, and Radioactive Isotope Physics Laboratory of the RIKEN Nishina Center for supporting their stay during the experiments.

Published
2017

26. Quasifree Neutron Knockout from Ca54 Corroborates Arising N=34 Neutron Magic Number

Author

V. Wagner, V. Somà, F. Flavigny, K. Moschner, S. Y. Park, V. Panin, Kathrin Wimmer, M. MacCormick, S. Takeuchi, M. L. Cortés, S. Franchoo, Hideaki Otsu, D. Calvet, D. M. Rossi, Toshio Kobayashi, K. Yoneda, Tomohiro Uesaka, Masaki Sasano, T. Lokotko, P. Koseoglou, Dóra Sohler, H. Baba, N. Paul, P. A. Söderström, David Steppenbeck, Nobuyuki Chiga, E. Sahin, Petr Navrátil, Thomas Aumann, Takashi Nakamura, F. Browne, S. J. Chen, Donghang Yan, V. Werner, T. Isobe, R.-B. Gerst, P. Doornenbal, T. Koiwai, F. Château, A. Corsi, A. Gillibert, Takaharu Otsuka, Hiroyoshi Sakurai, A. Delbart, F. Raimondi, H. Yamada, Shuopei Wang, Y. L. Sun, Victor Vaquero, T. Motobayashi, L. X. Chung, H. Törnqvist, J. M. Gheller, Yasuhiro Togano, W. Rodriguez, Y. Chazono, A. Giganon, Carlo Barbieri, Kazuyuki Ogata, C. Lehr, Masahiro Yasuda, C. Hilaire, N. L. Achouri, Yosuke Kondo, Julien Gibelin, X. X. Xu, B. D. Linh, J. Kahlbow, Igor Gašparić, H. N. Liu, A. Obertelli, L. Zanetti, Yutaka Utsuno, Jenny Lee, Yuya Kubota, V. Lapoux, K. Yoshida, Dong-Wook Kim, O. Aktas, Zaihong Yang, I. Murray, K. I. Hahn, and L. Stuhl

Subjects
Physics, Hydrogen, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, Impulse (physics), 01 natural sciences, Vertex (geometry), Isotopes of calcium, Transverse plane, chemistry, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Excitation
Abstract

Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a ^{54}Ca beam striking on a liquid hydrogen target at ∼200 MeV/u. A significantly larger cross section to the p_{3/2} state compared to the f_{5/2} state observed in the excitation of ^{53}Ca provides direct evidence for the nature of the N=34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

Published
2019

27. New spectroscopic information on Tl211,213 : A changing structure beyond the N=126 shell closure

Author

S. Leoni, Hans Geissel, A. Sharma, Robert Hoischen, A. M. Denis Bacelar, A. Bracco, Enrique Casarejos, N. Goel, Matthew Reed, A. Prochazka, D. Bazzacco, S. M. Lenzi, T.P.D. Swan, Imrich Szarka, N. Al-Dahan, Philip M Walker, T. Habermann, A. Gottardo, J. Benlliure, Andrea Corsi, A. Gadea, S. Klupp, E. Gregor, C. Nociforo, Zs. Dombrádi, Alison Bruce, D. Mengoni, Oliver Wieland, Roberto Vicençotto Ribas, A. I. Morales, M. Bunce, Helmut Weick, A. Y. Deo, F. Nowacki, K. Eppinger, C. Domingo-Pardo, A. Algora, M. L. Cortés, E. Sahin, S. Pietri, M. Bowry, J. Alcántara Núñez, H. Schaffner, F. Naqvi, T. Engert, K. Steiger, R. Janik, F. C. L. Crespi, M. Pfützner, J. Gerl, N. Alkhomashi, Maria Doncel, H. J. Wollersheim, W. Prokopowicz, F. Farinon, B. Million, C. A. Ur, Peter Strmen, Y. Ayyad, Davinder Siwal, S. K. Mandal, Roberto Menegazzo, F. Camera, Enrico Maglione, J. J. Valiente-Dobón, P. Boutachkov, Dirk Rudolph, J. Grebosz, P. R. P. Allegro, S. Lunardi, P. H. Regan, G. de Angelis, G. Benzoni, F. Recchia, D. R. Napoli, G. F. Farrelly, Zs. Podolyák, M. Górska, Branislav Sitar, N. Kurz, and I. Kojouharov

Subjects
Physics, Nuclear physics, Fragmentation (mass spectrometry), chemistry, Isotope, 010308 nuclear & particles physics, 0103 physical sciences, Nuclear structure, chemistry.chemical_element, Gamma spectroscopy, Uranium, 010306 general physics, 01 natural sciences
Abstract

The neutron-rich isotopes 211;213Tl, beyond the N = 126 shell-closure, have been studied for the first time in isomer γ-ray decay, exploiting the fragmentation of a primary uranium beam at the FRS-RISING (FRagment Separator-Rare ISotopes INvestigation at GSI) setup at GSI. The observed isomeric states in 211;213Tl show a deviation from the seniority-like scheme of 209Tl. The possible interpretation of the data is discussed on the basis of energy-level systematics and shell-model calculations.

Published
2019

28. Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei

Author

A. Corsi, V. Lapoux, Zs. Dombradi, K. Matsui, David Steppenbeck, A. Gillibert, Alan Peyaud, Shoko Koyama, Toshiaki Ando, C. M. Shand, Hiroyoshi Sakurai, M. Rudigier, F. Browne, L. Olivier, Raymond J. Carroll, K. Yoneda, E. Sahin, Yoshiaki Shiga, Bing Ding, F. Château, Pieter Doornenbal, Hidetada Baba, Tomoyuki Saito, Tohru Motobayashi, Zs. Podolyák, Satoru Momiyama, F. Giacoppo, C. R. Nita, T. Sumikama, H. Wang, Megumi Niikura, A. Gottardo, Jenny Lee, M. Dewald, Zs. Vajta, R. Orlandi, Shuichi Ota, E. C. Pollacco, K. Hadynska-Klek, F. Flavigny, P. A. Söderström, Daisuke Suzuki, Yuya Kubota, C. Lizarazo, D. Calvet, S. Nagamine, C. Péron, Tomohiro Uesaka, R. Lozeva, Hideaki Otsu, N. Paul, Shenjian Chen, G. Authelet, Noritsugu Nakatsuka, Ryo Taniuchi, A. Delbart, Carlos A. Bertulani, J. M. Gheller, Zi Hong Liu, V. Werner, T. Arici, M. Matsushita, Masaki Sasano, M. Lettmann, B. D. Linh, C. Santamaria, Alison Bruce, J. L. Rodriguez-Sanchez, Satoshi Takeuchi, I. Stefan, M. Górska, S. Franchoo, C. Louchart, Zhengyu Xu, Zena Patel, J.-Y. Roussé, Tadaaki Isobe, S. Nishimura, A. Jungclaus, Victor Vaquero, T. Miyazaki, M. L. Cortés, A. Obertelli, K. Moschner, Kathrin Wimmer, Z. Korkulu, Jin Wu, L. X. Chung, C. R. Nobs, Jian Liu, A. Blazhev, and A. Giganon

Subjects
Physics, Hydrogen, Proton, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Nuclear physics, chemistry, Cascade, Pairing, 0103 physical sciences, Bound state, Physics::Accelerator Physics, Neutron, Nuclear Experiment, 010306 general physics, Nucleon, Beam (structure)
Abstract

Fifty-five inclusive single nucleon removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at � 250 MeV/nucleon were measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semi-microscopic model predictions,highlighting the enhanced role of low-lying level densities in nucleon removal cross sections from loosely-bound nuclei.

Published
2019

29. Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei

Author

N, Paul, A, Obertelli, C A, Bertulani, A, Corsi, P, Doornenbal, J L, Rodriguez-Sanchez, G, Authelet, H, Baba, D, Calvet, F, Château, S, Chen, A, Delbart, J-M, Gheller, A, Giganon, A, Gillibert, T, Isobe, V, Lapoux, M, Matsushita, S, Momiyama, T, Motobayashi, M, Niikura, H, Otsu, C, Péron, A, Peyaud, E C, Pollacco, J-Y, Roussé, H, Sakurai, C, Santamaria, M, Sasano, Y, Shiga, D, Steppenbeck, S, Takeuchi, R, Taniuchi, T, Uesaka, H, Wang, K, Yoneda, T, Ando, T, Arici, A, Blazhev, F, Browne, A M, Bruce, R, Carroll, L X, Chung, M L, Cortés, M, Dewald, B, Ding, Zs, Dombradi, F, Flavigny, S, Franchoo, F, Giacoppo, M, Górska, A, Gottardo, K, Hadynska-Klek, Z, Korkulu, S, Koyama, Y, Kubota, A, Jungclaus, J, Lee, M, Lettmann, B D, Linh, J, Liu, Z, Liu, C, Lizarazo, C, Louchart, R, Lozeva, K, Matsui, T, Miyazaki, K, Moschner, S, Nagamine, N, Nakatsuka, C, Nita, S, Nishimura, C R, Nobs, L, Olivier, S, Ota, Z, Patel, Zs, Podolyák, M, Rudigier, E, Sahin, T Y, Saito, C, Shand, P-A, Söderström, I G, Stefan, T, Sumikama, D, Suzuki, R, Orlandi, V, Vaquero, Zs, Vajta, V, Werner, K, Wimmer, J, Wu, and Z, Xu

Subjects
Nuclear Theory, Physics::Accelerator Physics, Nuclear Experiment
Abstract

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼ 250 MeV / nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

Published
2019

30. How Robust is the N=34 Subshell Closure? First Spectroscopy of Ar52

Author

Nobuyuki Chiga, T. Lokotko, Si Chen, T. Koiwai, Takashi Nakamura, D. Calvet, K. Moschner, E. Sahin, Yosuke Kondo, A. Corsi, N.L. Achouri, Kathrin Wimmer, T. Kobayashi, F. Browne, X. X. Xu, David Steppenbeck, B. D. Linh, A. Delbart, J. M. Gheller, V. Wagner, H. Törnqvist, P. Doornenbal, M. MacCormick, R.-B. Gerst, Igor Gašparić, C. Lehr, Hiroyoshi Sakurai, Masahiro Yasuda, C. Hilaire, H.N. Liu, A. Giganon, F. Flavigny, M. L. Cortés, T. Motobayashi, S. Franchoo, Thomas Aumann, C.A. Bertulani, A. Gillibert, V. Panin, Hideaki Otsu, L. X. Chung, P. A. Söderström, Gustav R. Jansen, Hirofumi Yamada, Masaki Sasano, R. Stroberg, D. Sohler, Julien Gibelin, L. Zanetti, Victor Vaquero, V. Lapoux, T. Isobe, N. Paul, S. Wang, Yasuhiro Togano, Jenny Lee, Achim Schwenk, Yuya Kubota, Satoshi Takeuchi, V. Werner, A. Obertelli, F. Château, P. Koseoglou, Gaute Hagen, Dong-Wook Kim, O. Aktas, Zaihong Yang, I. Murray, K. I. Hahn, L. Stuhl, Jason D. Holt, Tomohiro Uesaka, K. Yoneda, S. Y. Park, Duo Yan, D. M. Rossi, H. Baba, Y. L. Sun, T. D. Morris, and W. Rodriguez

Subjects
Physics, Isotope, Closure (topology), General Physics and Astronomy, 01 natural sciences, 3. Good health, Neutron number, 0103 physical sciences, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nuclear theory, Excitation, Energy (signal processing)
Abstract

The first γ-ray spectroscopy of ^{52}Ar, with the neutron number N=34, was measured using the ^{53}K(p,2p) one-proton removal reaction at ∼210 MeV/u at the RIBF facility. The 2_{1}^{+} excitation energy is found at 1656(18) keV, the highest among the Ar isotopes with N>20. This result is the first experimental signature of the persistence of the N=34 subshell closure beyond ^{54}Ca, i.e., below the magic proton number Z=20. Shell-model calculations with phenomenological and chiral-effective-field-theory interactions both reproduce the measured 2_{1}^{+} systematics of neutron-rich Ar isotopes, and support a N=34 subshell closure in ^{52}Ar.

Published
2019

31. Spectroscopy of neutron-rich scandium isotopes

Author

A. Delbart, T. Motobayashi, L. Zanetti, Julien Gibelin, Tomohiro Uesaka, T. Kobayashi, X. X. Xu, H. Toernqvist, Si-Ge Chen, P. A. Söderström, S. Wang, F. Flavigny, A. Obertelli, V. Wagner, M. Lettmann, D. Calvet, J. M. Gheller, T. Isobe, A. Giganon, F. Château, Thomas Aumann, Makoto Yasuda, Victor Vaquero, A. Gillibert, V. Panin, L. X. Chung, E. Sahin, S. Y. Park, T. Lokotko, Duo Yan, P. Doornenbal, K. Moschner, M. MacCormick, C. Hilaire, Kathrin Wimmer, Alessandra Corsi, Satoshi Takeuchi, Takashi Nakamura, R.-B. Gerst, B. D. Linh, M. L. Cortés, S. Franchoo, Igor Gašparić, H. N. Liu, K. Yoneda, C. Lehr, Jenny Lee, F. Browne, Yuya Kubota, Masaki Sasano, N. Paul, D. M. Rossi, V. Werner, Yasuhiro Togano, Yosuke Kondo, H. Baba, N. L. Achouri, Hideaki Otsu, Hirofumi Yamada, Y. L. Sun, Dong-Wook Kim, O. Aktas, V. Lapoux, Zaihong Yang, I. Murray, K. I. Hahn, David Steppenbeck, L. Stuhl, W. Rodriguez, Nobuyuki Chiga, T. Koiwai, Norbert Pietralla, D. Sohler, P. Koseoglou, Hiroyoshi Sakurai, RIKEN Nishina Center for Accelerator-Based Science, Technische Universität Darmstadt, Helmholtz Centre for Heavy Ion Research, Federal Ministry of Education and Research (Germany), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), 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), 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), 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 Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, History, Isotope, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Computer Science Applications, Education, International school, Neutron physics, Nuclear physics, chemistry, 0103 physical sciences, Physics::Accelerator Physics, ddc:530, Neutron, Scandium, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

7 pags., 7 figs. -- XXIII International School on Nuclear Physics, Neutron Physics and Applications 22-28 September 2019, Varna, Bulgaria, Within the SEASTAR III campaign at the Radioactive Isotope Beam Factory, at the RIKEN Nishina Center, neutron-rich isotopes in the vicinity of 53K were produced from the fragmentation of the primary 70Zn beam on a 9Be target. After nucleon knockout reactions on the secondary liquid hydrogen MINOS target the known γ rays of the neutron-rich 55Sc isotope were observed (shown in this proceedings) and γ rays from 57,59Sc isotopes have been identified for the first time. The evolution of the occupied nucleon orbitals of these nuclei in the ground and excited state is investigated under the prism of the tensor force., We are grateful to the RIKEN Nishina Center accelerator staff for their work in the primary beam delivery and the BigRIPS team for preparing the secondary beams. This work was supported by the cooperation between TU Darmstadt and the GSI Helmholtz Center for Heavy Ion Research, by the Helmholtz Graduate School for Hadron and Ion Research for FAIR and its abroad program and the BMBF under grant No. 05P19RDFN1. D.S. was supported by projects No. GINOP2.3.3-15-2016-00034 and No. K128947.

Published
2020

32. Restoration of the natural E(1/21+) - E(3/21+) energy splitting in odd-K isotopes towards N = 40

Author

David Steppenbeck, B. D. Linh, H. Törnqvist, Igor Gašparić, H. N. Liu, Kazuki Yoshida, Yosuke Kondo, Toshio Kobayashi, P. A. Söderström, K. Yoneda, N. Paul, Carlo Barbieri, S. Y. Park, D. M. Rossi, V. Lapoux, Donghang Yan, H. Baba, K. Moschner, Masaki Sasano, V. Werner, Yutaka Utsuno, Yoshiki Chazono, S. Wang, D. Sohler, Zaihong Yang, I. Murray, K. I. Hahn, L. Stuhl, Kathrin Wimmer, Jenny Lee, J. M. Gheller, Victor Vaquero, R.-B. Gerst, Takaharu Otsuka, F. Browne, A. Obertelli, Nobuyuki Chiga, D. Calvet, T. Isobe, Hiroyoshi Sakurai, T. Koiwai, Yuya Kubota, C. Hilaire, T. Motobayashi, F. Nowacki, F. Château, A. Delbart, C. Lehr, A. Gillibert, M. MacCormick, Julien Gibelin, A. Corsi, X. X. Xu, V. Panin, M. L. Cortés, Thomas Aumann, O. Aktas, S. Franchoo, Si-Ge Chen, L. X. Chung, L. Zanetti, A. Giganon, Francesco Raimondi, Hideaki Otsu, Hirofumi Yamada, Tomohiro Uesaka, W. Rodriguez, F. Flavigny, Yasuhiro Togano, T. Lokotko, E. Sahin, N.L. Achouri, Y.L. Sun, Takashi Nakamura, Petr Navrátil, P. Doornenbal, Thomas Duguet, V. Wagner, Satoshi Takeuchi, D. Kim, V. Somà, Masahiro Yasuda, Kazuyuki Ogata, and P. Koseoglou

Subjects
Physics, Nuclear and High Energy Physics, Chemical substance, Isotope, 010308 nuclear & particles physics, SHELL model, 01 natural sciences, Vertex (geometry), Ab initio quantum chemistry methods, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Nucleon, Spectroscopy
Abstract

We report on the first γ-ray spectroscopy of 51,53K produced via the 52,54Ca(p,2p) reactions at ∼250 MeV/nucleon. Unambiguous final-state angular-momentum assignments were achieved for beam intensities down to few particles per second by using a new technique based on reaction vertex tracking combined with a thick liquid-hydrogen target. Through γ-ray spectroscopy and exclusive parallel momentum distribution analysis, 3/2+ ground states and 1/2+ first excited states in 51,53K were established quantifying the natural ordering of the 1 d 3 / 2 and 2 s 1 / 2 proton-hole states that are restored at N = 32 and 34. State-of-the-art ab initio calculations and shell-model calculations with improved phenomenological effective interactions reproduce the present data and predict consistently the increase of the E(1/2 1 + ) - E(3/2 1 + ) energy differences towards N = 40.

Published
2020

33. First Spectroscopy of the Near Drip-line Nucleus ^{40}Mg

Author

Stefanos Paschalis, Satoru Momiyama, Marina Petri, P. Schrock, C. M. Campbell, Hiroyoshi Sakurai, Yukichi Tanaka, M. MacCormick, M. L. Cortés, R. M. Clark, A. O. Macchiavelli, F. Browne, Megumi Niikura, Ryo Taniuchi, Kathrin Wimmer, M. Salathe, R. Kanungo, I. Murray, Hua-Lei Wang, Nori Aoi, P. Fallon, Si-Ge Chen, Eiji Ideguchi, David Steppenbeck, M. Cromaz, H. L. Crawford, Satoshi Takeuchi, P. Doornenbal, and M. Jones

Subjects
Physics, General Physics, 010308 nuclear & particles physics, Nuclear Theory, Center (category theory), General Physics and Astronomy, 01 natural sciences, Mathematical Sciences, Engineering, Excited state, 0103 physical sciences, Physical Sciences, Nuclear drip line, Atomic physics, 010306 general physics, Nucleon, Spectroscopy, Nuclear Experiment, Excitation, Magic number (physics), Line (formation)
Abstract

One of the most exotic light neutron-rich nuclei currently accessible for experimental study is ^{40}Mg, which lies at the intersection of the nucleon magic number N=28 and the neutron drip line. Low-lying excited states of ^{40}Mg have been studied for the first time following a one-proton removal reaction from ^{41}Al, performed at the Radioactive Isotope Beam Factory of RIKEN Nishina Center with the DALI2 γ-ray array and the ZeroDegree spectrometer. Two γ-ray transitions were observed, suggesting an excitation spectrum that shows unexpected properties as compared to both the systematics along the Z=12, N≥20 Mg isotopes and available state-of-the-art theoretical model predictions. A possible explanation for the observed structure involves weak-binding effects in the low-lying excitation spectrum.

Published
2018

34. Study of multi-neutron systems with SAMURAI spectrometer

Author

K. Yoneda, Z. Elekes, Masaki Sasano, Heiko Scheit, Atsumi Saito, N. Inabe, I. Stefan, J. Tscheuschner, Mohsen Harakeh, Julien Gibelin, M. A. Knösel, K. Boretzky, Z. Ge, Takashi Nakamura, D. Kim, H. Sato, J. Kahlbow, Igor Gašparić, Y. Yasuda, Susumu Shimoura, T. Isobe, Juzo Zenihiro, M. Caamaño, Yosuke Kondo, S. Masuoka, H. Suzuki, A. Hirayama, S. W. Huang, C. A. Douma, B. M. Godoy, Z. Halász, H. Yamada, C. Lehr, M. Böhmer, Nobuyuki Chiga, A. Revel, N. L. Achouri, P. Koseoglou, Kathrin Wimmer, V. Wagner, N. A. Orr, M. Potlog, M. Miwa, B. Yang, A. Obertelli, T. Harada, H. T. Törnqvsit, S. Reichert, H. Miki, D. S. Ahn, T. Tomai, István Kuti, J. Mayer, J. Tanaka, S. Park, Yasuhiro Togano, M. Parlog, Naoki Fukuda, Yu-xin Liu, S. Chen, V. Panin, L. Zanetti, F. Schindler, S. Storck, T. Shimada, Tomohiro Uesaka, J. Feng, M. Matsumoto, Zaihong Yang, U. Forsberg, Roman Gernhäuser, I. Murray, F. Dufter, D. Symochko, L. Stuhl, J. M. Gheller, Hideaki Otsu, D. Beaumel, T. Kobayashi, H. Takeda, A. Gillibert, D. Cortina, P. Doornenbal, L. Yang, Nasser Kalantar-Nayestanaki, Satoshi Takeuchi, Thomas Aumann, Stefanos Paschalis, T. Fujino, D. M. Rossi, H. Baba, Yohei Shimizu, M. L. Cortés, F. M. Marqués, B. Fernández-Domínguez, Yuya Kubota, Yukie Maeda, S. K. Kim, P. J. Li, 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), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), Normandie Université (NU)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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, Firm conclusion, Spectrometer, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 010305 fluids & plasmas, Nuclear physics, 0103 physical sciences, Tetraneutron, Neutron, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract

The tetraneutron has been drawing the attention of the nuclear physics community for decades, but a firm conclusion on its existence and properties is still far from being reached despite many experimental and theoretical efforts. New measurements have recently been performed at RIBF with the SAMURAI spectrometer by applying complementary reaction probes, which will help to pin down the properties of this four-neutron system., Comment: 5 pages, 2 figures, conference proceedings of XXII International Conference on Few-Body Problems in Physics (FB22), Caen, France, July 2018

Published
2018

35. Inelastic scattering of neutron-rich Ni and Zn isotopes off a proton target

Author

R. Lozeva, M. Lettmann, J.-Y. Roussé, Tadaaki Isobe, Pieter Doornenbal, F. Nowacki, Zena Patel, Satoshi Takeuchi, H. Otsu, K. Matsui, M. L. Cortés, K. Yoneda, C. Santamaria, S. Franchoo, Tohru Motobayashi, Hidetada Baba, E. Sahin, Hiroyoshi Sakurai, Shuichi Ota, C. Péron, S. Nishimura, G. Authelet, F. Giacoppo, Shunpei Koyama, E. C. Pollacco, Alan Peyaud, Jin Wu, L. X. Chung, H. Wang, F. Château, F. Browne, Ryo Taniuchi, J. M. Gheller, Marc Dupuis, T. Sumikama, V. Lapoux, D. Calvet, Zs. Vajta, David Steppenbeck, A. Gillibert, A. Obertelli, Daisuke Suzuki, A. Gottardo, P. A. Söderström, Jenny Lee, S. M. Lenzi, Yoshiaki Shiga, A. Corsi, Kathrin Wimmer, K. Hadynska-Klek, Yuya Kubota, Megumi Niikura, Sophie Péru, Tomohiro Uesaka, I. Stefan, Zs. Dombrádi, C. M. Shand, Norbert Pietralla, A. Delbart, V. Werner, Z. Korkulu, Zhengyu Xu, T. Miyazaki, M. Matsushita, L. Olivier, C. Louchart, Masaki Sasano, Satoru Momiyama, Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Scattering, Hadron, Nuclear Theory, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Isotopes of zinc, Gamma spectroscopy, Neutron, 010306 general physics, Nucleon, Nuclear Experiment
Abstract

International audience; Proton inelastic scattering of Ni72,74 and Zn76,80 ions at energies around 235 MeV/nucleon was performed at the Radioactive Isotope Beam Factory and studied using γ-ray spectroscopy. Angular integrated cross sections for direct inelastic scattering to the 21+ and 41+ states were measured. The Jeukenne-Lejeune-Mahaux folding model, extended beyond 200 MeV, was used together with neutron and proton densities stemming from quasiparticle random-phase approximation (QRPA) calculations to interpret the experimental cross sections and to infer neutron to proton matrix element ratios. In addition, coupled-channels calculations with a phenomenological potential were used to determine deformation lengths. For the Ni isotopes, correlations favor neutron excitations, thus conserving the Z=28 gap. A dominance of proton excitation, on the other hand, is observed in the Zn isotopes, pointing to the conservation of the N=50 gap approaching Ni78. These results are in agreement with QRPA and large-scale shell-model calculations.

Published
2018

36. Silicon photomultipliers as readout for a segmented Time-of-Flight plastic detector

Author

H. Schaffner, S. Saha, J. Vesic, P. Bednarczyk, J. Gerl, M. Reese, M. Górska, S. Doublet, F. Ameil, M. L. Cortés, Norbert Pietralla, École Centrale de Lyon (ECL), and Université de Lyon

Subjects
Nuclear and High Energy Physics, Ion beam, Physics::Instrumentation and Detectors, STRIPS, Scintillator, Silicon photomultiplier, 01 natural sciences, Time-of-flight measurement, Particle identification, law.invention, law, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Instrumentation, Heavy-ion detection, Physics, Plastic scintillator, 010308 nuclear & particles physics, business.industry, Detector, Time resolution, Time of flight, Optoelectronics, business, Beam (structure)
Abstract

International audience; Particle identification at radioactive ion beam facilities requires Time-of-Flight detectors with an optimal time resolution and high rate capability. Segmented plastic scintillators are a common option for such detectors. A promising approach to cope with the high segmentation of modern devices is the use of silicon photomultipliers (SiPMs) as readout of the Time-of-Flight detectors. A prototype device consisting of strips of plastic scintillator of 4.4 × 100 × 1 mm 3 readout at both ends by SiPMs of two different sizes was tested using a 124 Xe beam at 600 MeV/nucleon. Timing and time-over-threshold information were extracted. The time resolution of the prototype was found to vary with the applied voltage and the SiPM size. After optimizing the voltage, resolutions of 14.3(10) ps and 10.4(1) ps were obtained for SiPMs of 1 × 1 mm 2 and 3 × 3 mm 2 respectively. These results point to SiPMs being suitable as readout of plastic scintillators at radioactive ion beam facilities.

Published
2018

37. Study of isomeric states in $^{198,200,202,206}$Pb and $^{206}$Hg populated in fragmentation reactions

Author

A. Gottardo, P. Thöle, D. Bazzacco, R. Menegazzo, Dirk Rudolph, Jan Taprogge, E. Wilson, I. Burrows, C. Domingo-Pardo, Pavel Golubev, Claes Fahlander, D. Mengoni, H. J. Wollersheim, A. Pullia, K. Moschner, Herbert Hess, A. Jungclaus, Luis Sarmiento, Vicente González, P. Reiter, J. Eberth, C. Michelagnoli, O. Wieland, Begoña Quintana, F. Ameil, Eric Clément, Th Moeller, Zs. Podolyák, J. Simpson, A. Gadea, Anna Wendt, M. Reese, P. Désesquelles, T. Arici, M. Hackstein, B. Bruyneel, T. Habermann, I. Kojouharov, D. Ralet, E. Gregor, Zena Patel, C. Lizarazo, C. Louchart, Pushpendra Singh, A. Givechev, R. Stegmann, M. L. Cortés, O. Stezowski, J. J. Valiente Dobon, N. Kurz, M. Górska, C. Bauer, N. Lalović, T. Alexander, E. Merchan, Enrique Sanchis, N. Goel, Edward Simpson, J. Gerl, Jnaneswari Gellanki, Norbert Pietralla, M. Bowry, C. Stahl, M. Lettmann, D. R. Napoli, R. Kumar, G. Rainovski, G. Guastalla, J. Jolie, S. Pietri, B. Birkenbach, M. D. Salsac, M. A. Bentley, D. S. Judson, H. Schaffner, P. Boutachkov, P. H. Regan, R. Wood, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), 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), 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), AGATA, 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), 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
Nuclear and High Energy Physics, isomeric decays, Astrophysics::High Energy Astrophysical Phenomena, Population, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Fragmentation (mass spectrometry), Subatomic Physics, 0103 physical sciences, Gamma spectroscopy, Gamma-ray spectroscopy, 010306 general physics, education, Nuclear Experiment, Physics, education.field_of_study, Isotope, 010308 nuclear & particles physics, Nuclear shell model, direct reactions, relativistic projectile fragmentation, electromagnetic transitions, nuclear shell model, AGATA, PreSPEC-AGATA, Atomic physics, Beam (structure)
Abstract

International audience; Isomeric states in isotopes in the vicinity of doubly-magic 208Pb were populatedfollowing reactions of a relativistic 208Pb primary beam impinging on a9Be fragmentation target. Secondary beams of 198,200,202,206Pb and 206Hg wereisotopically separated and implanted in a passive stopper positioned in thefocal plane of the GSI Fragment Separator. Delayed γ rays were detected withthe Advanced Gamma Tracking Array (AGATA). Decay schemes were reevaluatedand interpreted with shell-model calculations. The momentumdependentpopulation of isomeric states in the two-nucleon hole nuclei206Pb/206Hg was found to differ from the population of multi neutron-holeisomeric states in 198,200,202Pb.

Published
2018

38. 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

39. Signatures of triaxiality in low-spin spectra of $^{86}$Ge

Author

I. Stefan, Alessandra Corsi, C. M. Shand, L. Olivier, M. Dewald, Satoru Momiyama, Megumi Niikura, Norbert Pietralla, Tomohiro Uesaka, A. Gillibert, Jian Liu, R. J. Caroll, Bing Ding, Victor Vaquero, A. Gottardo, S. Nagamine, F. Browne, Tomás R. Rodríguez, A. Delbart, D. Calvet, Zs. Podolyák, Ryo Taniuchi, A. Blazhev, C. R. Nobs, T. Arici, T. Saito, C. Lizarazo, G. Authelet, Zena Patel, M. L. Cortés, J.-Y. Roussé, C. R. Nita, Zhenci Xu, J. M. Gheller, David Steppenbeck, A. Jungclaus, M. Lettmann, A. Giganon, A. Obertelli, F. Château, Pieter Doornenbal, Alison Bruce, Kamila Sieja, Toshiaki Ando, M. Górska, Si-Ge Chen, N. Paul, Noritsugu Nakatsuka, M. Rudigier, P. A. Söderström, Zi Hong Liu, V. Werner, C. Santamaria, L. X. Chung, Hiroyoshi Sakurai, T. Motobayashi, K. Moschner, Hidetada Baba, Kathrin Wimmer, B. D. Linh, Jenny Lee, V. Lapoux, S. Franchoo, F. Flavigny, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Federal Ministry of Education and Research (Germany), SCOAP, European Commission, Ministerio de Economía y Competitividad (España), Vietnam Academy of Science and Technology, Science and Technology Facilities Council (UK), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien ( IPHC ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA ), Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), 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, History, Time projection chamber, Spectrometer, 010308 nuclear & particles physics, Fission, State (functional analysis), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Spectral line, Computer Science Applications, Education, Nuclear physics, MINOS, 0103 physical sciences, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Spectroscopy, Spin (physics)
Abstract

7 pags., 4 figs. -- XXII International School on Nuclear Physics, Neutron Physics and Applications. -- Open Access funded by Creative Commons Atribution Licence 3.0, Low-spin states of neutron-rich Ge-84,Ge-86,Ge-88 were measured by in-flight gamma-ray spectroscopy at 270 MeV/u at the RIKEN-RIBF facility. The exotic beams have been produced by primary U-238 in-flight fission reactions and impinged on the MINOS device. MINOS combines a 10-cm long LH2 target with a Time Projection Chamber (TPC) to reconstruct the reaction vertices. The reactions were selected by the BigRIPS and the ZeroDegree spectrometers for the incoming and outgoing channels, respectively. Emitted gamma radiation was detected by the NaI-array DALI2. De-excitations from the 6(1)(+), 4(1,2)(+), and 2(1,2)(+) states of Ge-84,Ge- 86 and 4(1)(+) and 26 states of Ge-88 were observed. The data are compared to state-of-the-art shell model and beyond-mean-field calculations. Furthermore, a candidate for a 3(1)(+) state of Ge-86 was identified. This state plays a key role in the discussion of ground-state triaxiality of Ge-86, along with other features of the low-energy level scheme., We acknowledge support from the German BMBF Grant Nos. 05P12RDFN1, 05P12RDFN8 and 05P15PKFNA, the ERC Grant No. MINOS258567, the Spanish Ministerio de Economıa y Competitividad under contracts FPA2014-57196-C5-4-P and FIS−2014−53434, the Vietnam Ministry of Science and Technology, as well as from the Science and Technology Facilities Council (STFC). We further thank GSI for providing computing facilities

Published
2017

40. A revised B(E2;2+ 1 $ \rightarrow$ → 0+ 1) value in the semi-magic nucleus 210Po

Author

A. Dewald, M. Spieker, D. Kocheva, P. Scholz, C. Müller-Gatermann, R. Altenkirch, V. Karayonchev, A. Blazhev, M. Djongolov, M. Rudigier, P. Thöle, K. A. Gladnishki, Norbert Pietralla, V. Yu. Ponomarev, F. Diel, S. Ansari, D. Wölk, J. M. Keatings, N. Warr, Th. Braunroth, C. Stahl, P. Van Isacker, V. Werner, G. Rainovski, A. Astier, M. Stoyanova, A. Hennig, J. Litzinger, J. Jolie, M. L. Cortés, C. Fransen, W. Witt, K. O. Zell, E. Kluge, R. Stegmann, P. Spagnoletti, P. Petkov, and Marcus Scheck

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Phonon, Yrast, Hadron, Value (computer science), State (functional analysis), 01 natural sciences, medicine.anatomical_structure, 0103 physical sciences, medicine, Nuclear fusion, MAGIC (telescope), Atomic physics, 010306 general physics, Nucleus
Abstract

The lifetimes of the $ 2^+_1$ , the $ 2^+_2$ and the $ 3^-_1$ states of$^{210}$Po have been measured in the$^{208}$Pb($^{12}$C,$^{10}$Be)$^{210}$Po transfer reaction by the Doppler-shift attenuation method. The result for the lifetime of the $ 2^+_1$ state is about three times shorter than the adopted value. However, the new value still does not allow for a consistent description of the properties of the yrast $ 2^+_1$ , $ 4^+_1$ , $ 6^+_1$ , and $ 8^+_1$ states of$^{210}$Po in the framework of nuclear shell models. Quasi-particle Phonon Model (QPM) calculations also cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

Published
2017

41. Triaxiality of neutron-rich Ge84,86,88 from low-energy nuclear spectra

Author

L. Olivier, Megumi Niikura, Alison Bruce, Tomohiro Uesaka, I. Stefan, M. Rudigier, Z. Patel, A. Giganon, A. Obertelli, C. R. Nita, Tomás R. Rodríguez, C. M. Shand, Satoru Momiyama, N. Paul, Noritsugu Nakatsuka, S. Nagamine, F. Château, Ryo Taniuchi, Bing Ding, J.-Y. Roussé, Zs. Podolyák, C. R. Nobs, K. Moschner, Zhengyu Xu, T. Arici, Zi Hong Liu, V. Werner, A. Jungclaus, Hiroyoshi Sakurai, Kathrin Wimmer, M. Górska, David Steppenbeck, C. Lizarazo, F. Flavigny, H. Baba, T. Saito, G. Authelet, Kamila Sieja, Toshiaki Ando, M. Dewald, Si-Ge Chen, P. A. Söderström, R. J. Caroll, D. Calvet, Tohru Motobayashi, P. Doornenbal, J. M. Gheller, L. X. Chung, A. Gillibert, Jian Liu, A. Blazhev, Victor Vaquero, Andrea Corsi, M. Lettmann, F. Browne, A. Gottardo, Jenny Lee, M. L. Cortés, S. Franchoo, C. Santamaria, B. D. Linh, V. Lapoux, Norbert Pietralla, and A. Delbart

Subjects
Physics, Low energy, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences, Spectral line
Abstract

ray transitions between low-spin states of the neutron-rich 84;86;88Ge were measured by means of in-flight -ray spectroscopy at 270 MeV/u. Excited 6+ 1 , 4+ 1;2 and 2+ 1;2 states of 84;86Ge and 4+ 1 and 2+ 1;2 states of 88Ge were observed. Furthermore a candidate for a 3+ 1 state of 86Ge was identified. This state plays a key role in the discussion of ground-state triaxiality of 86Ge, along with other features of its low-energy level scheme. A new region of triaxially deformed nuclei is proposed in the Ge isotopic chain.

Published
2017

42. Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60 : First Spectroscopy of Kr98,100

Author

J.-Y. Roussé, Hiroyoshi Sakurai, A. Jungclaus, T. Motobayashi, A. Corsi, Jian Liu, A. Delbart, Victor Vaquero, A. Blazhev, R. Orlandi, C. Lizarazo, J. Libert, G. Authelet, F. Château, Toshiaki Ando, K. Moschner, Zhengyu Xu, N. Paul, Noritsugu Nakatsuka, J. M. Gheller, T. Arici, I. Stefan, C. Santamaria, Zi Hong Liu, V. Werner, T. Saito, Si-Ge Chen, Kathrin Wimmer, Zena Patel, P. A. Söderström, A. Obertelli, S. Nagamine, M. Górska, M. L. Cortés, Alison Bruce, M. Girod, A. Giganon, Raymond J. Carroll, B. Ding, Zs. Podolyák, B. D. Linh, V. Lapoux, Megumi Niikura, Tomohiro Uesaka, L. X. Chung, C. R. Nobs, F. Browne, A. Gottardo, Jenny Lee, P. Doornenbal, A. Gillibert, C. M. Shand, F. Flavigny, H. Baba, C. R. Nita, J.-P. Delaroche, S. Franchoo, Ryo Taniuchi, David Steppenbeck, M. Dewald, L. Olivier, D. Calvet, Tomás R. Rodríguez, Satoru Momiyama, M. Lettmann, and M. Rudigier

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, Isotopes of krypton, 01 natural sciences, Neutron number, 0103 physical sciences, Isotopes of zirconium, Neutron, Gamma spectroscopy, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nucleon
Abstract

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich 98,100Kr isotopes obtained from 99,101Rb(p,2p) reactions at ∼ 220 MeV/nucleon. A reduction of the 2+ 1 state energies beyond N = 60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-theart beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0+ 2 , 2+ 2 ) state in 98Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory

Published
2017

43. Are There Signatures of Harmonic Oscillator Shells Far from Stability? First Spectroscopy of Zr110

Author

A. Giganon, M. Girod, T. Arici, J.-Y. Roussé, S. Franchoo, Toshiaki Ando, Ryo Taniuchi, A. Jungclaus, B. Ding, Si-Ge Chen, Jian Liu, P. A. Söderström, A. Gillibert, V. Lapoux, Zena Patel, B. D. Linh, Hiroyoshi Sakurai, C. M. Shand, A. Blazhev, C. R. Nita, A. Gottardo, Jenny Lee, T. Motobayashi, J. Libert, B. Bally, F. Château, A. Corsi, A. Delbart, H. Baba, F. Browne, Alison Bruce, Tomoaki Togashi, Megumi Niikura, Zhengyu Xu, J.-P. Delaroche, Tomohiro Uesaka, Tomás R. Rodríguez, P. Doornenbal, M. Rudigier, C. Santamaria, A. Obertelli, T. Saito, Satoru Momiyama, R. Orlandi, M. Lettmann, M. Górska, F. Flavigny, N. Paul, Noritsugu Nakatsuka, M. L. Cortés, Zi Hong Liu, V. Werner, Raymond J. Carroll, V. Vaquero, Paul-Henri Heenen, Zs. Podolyák, I. Stefan, Michaël Bender, C. Lizarazo, L. X. Chung, Yusuke Tsunoda, C. R. Nobs, K. Moschner, G. Authelet, J. M. Gheller, Kathrin Wimmer, David Steppenbeck, Takaharu Otsuka, M. Dewald, D. Calvet, Noritaka Shimizu, L. Olivier, and S. Nagamine

Subjects
Physics, Proton, 010308 nuclear & particles physics, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, 0103 physical sciences, Isotopes of zirconium, Rigid rotor, Atomic physics, 010306 general physics, Nucleon, Ground state, Spectroscopy, Harmonic oscillator, Excitation
Abstract

The first measurement of the low-lying states of the neutron-rich 110 Zr and 112 Mo was performed via in-beam γ -ray spectroscopy after one proton removal on hydrogen at ∼ 200 MeV / nucleon . The 2 + 1 excitation energies were found at 185(11) keV in 110 Zr , and 235(7) keV in 112 Mo , while the R 42 = E ( 4 + 1 ) / E ( 2 + 1 ) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of 110 Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z = 40 and N = 70 . The present data also invalidate predictions for a tetrahedral ground state symmetry in 110 Zr .

Published
2017

44. Lifetime measurement of neutron-rich even-even molybdenum isotopes

Author

Torbjörn Bäck, M. Labiche, M. Zielińska, M. Reese, A. Gadea, B. Million, T. Hüyük, F. Camera, R. Knoebel, T. Alexander, E. Gregor, N. Alkhomashi, Maria Doncel, A. Prochazka, A. Atac, D. Mengoni, L. J. Harkness-Brennan, Pushpendra Singh, A. Givechev, A. Gottardo, H. J. Wollersheim, T. Arici, Tomás R. Rodríguez, Alberto Pullia, D. Curien, E. Merchan, L. Sengele, C. Domingo-Pardo, Helmut Weick, A. Jungclaus, Herbert Hess, M. Dewald, P. Thoele, I. Kojouharov, G. Duchêne, S. Pietri, G. de Angelis, F. Didierjean, O. Stezowski, J. S. Winfield, N. Kurz, M. Hackstein, N. Goel, B. Birkenbach, P. Reiter, D. S. Judson, C. Stahl, E. Clément, F. Ameil, Pavel Golubev, P. Boutachkov, M. Górska, B. Bruyneel, A. Korichi, H. Schaffner, C. Scheidenberger, R. Avigo, F. Recchia, T. Goigoux, D. Bazzacco, Bo Cederwall, Vicente González, M. D. Salsac, P. Désesquelles, A. I. Morales, Zs. Podolyák, J. Gerl, J. J. Valiente Dobon, T. Habermann, Dirk Rudolph, Alison Bruce, D. Ralet, Luis Sarmiento, J. Jolie, D. R. Napoli, C. Louchart-Henning, Johan Nyberg, G. Guastalla, B. S. Nara Singh, Enrique Sanchis, M. Alaqeel, Oliver Wieland, G. Rainovski, J. Eberth, Norbert Pietralla, Hans Geissel, F. Ghazi Moradi, Anna Wendt, M. L. Cortés, S. Ceruti, N. Lalović, G. Henning, Begoña Quintana, F. Naqvi, W. Korten, 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), 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 Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-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), Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Science and Technology Facilities Council (UK), Federal Ministry of Education and Research (Germany), Swedish Research Council, European Commission, Helmholtz International Center for FAIR, 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), 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 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)-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), 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
chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Subatomic Physics, 0103 physical sciences, Neutron, ddc:530, 010306 general physics, Mass number, Physics, Isotope, 010308 nuclear & particles physics, relativistic projectile fragmentation, 3. Good health, secondary fragmentation, gamma-ray spectroscopy, chemistry, Molybdenum, Excited state, Quadrupole, Física nuclear, AGATA, Atomic physics, Energy (signal processing)
Abstract

D. Ralet et al. -- 11 pags., 10 figs., 3 tabs., Background: In the neutron-rich A≈100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A=100 up to mass A=108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the γ ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a γ-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A=100 to A=108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: τ=29.7-9.1+11.3 ps for the 4+ state of Mo108 and τ=3.2-0.7+0.7 ps for the 6+ state of Mo102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A=100 to A=108 with a maximum reached at N=64. The transition probabilities decrease for Mo108 which may be related to its well-pronounced triaxial shape indicated by the calculations., This work was supported by the BMBF under Grants No. 05P09RDFN4, No. 05P12RDFN8, and No. 05P12PKFNE and by the LOEWE center HIC for FAIR. Part of this work was supported by the P2IO excellence center. This work was also supported by the European Community FP7–Capacities, ENSAR Contract No. 262010, by the Swedish Research Council under Contracts No. 2010-147, No. 2010-3694, No. 2011-5253, No. 2011-6127, and No. 2014-5558, by the IN2P3- GSI No. 02-42 collaboration, by the Science and Technology Facilities Council (STFC) and by MINECO, Spain, under Grant No. FPA2014-57196-C5, and Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019

Published
2017

45. Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Author

P. A. Söderström, Hiroaki Suzuki, H. Takeda, H. Sakurai, Maya Takechi, Atsumi Saito, N. Fukuda, Shoichiro Masuoka, Ryo Nakajima, I. Murray, H. Baba, Takashi Nakamura, Kenichi Yoshida, A. Hirayama, T. Ozaki, Si-Ge Chen, X. H. Sun, Y. Shimizu, Keita Nakano, Toshiyuki Sumikama, Shigeru Kubono, S. Takeuchi, Yosuke Kondo, Hideaki Otsu, Hiroki Yamada, R. Hosoda, Yukinobu Watanabe, Hirohiko Sato, Yasuhiro Togano, Shoichiro Kawase, T. Isobe, K. Chikaato, Nobuyuki Chiga, Yukie Maeda, M. L. Cortés, M. Nishimura, D. S. Ahn, Y. Soudo, H. Wang, Masahiro Yasuda, Susumu Shimoura, Daisuke Suzuki, S. Nakayama, S. Michimasa, S. Kawakami, J. Suwa, T. Saito, T. Tomai, and Shoko Koyama

Subjects
Physics, Nuclear reaction, Nuclear transmutation, Proton, Nuclear Theory, General Physics and Astronomy, Radioactive waste, lcsh:Astrophysics, lcsh:QC1-999, Nuclear physics, Deuterium, lcsh:QB460-466, Physics::Accelerator Physics, Nuclear fusion, Neutron, Nuclear Experiment, lcsh:Physics, Fusion mechanism
Abstract

Searching for effective pathways for the production of proton-rich and neutron-rich isotopes is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. To produce nuclei effectively, an optimal combination of reaction mechanism and energy is required. We report a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 107Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential for incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste. Revealing how to effectively produce nuclei remains one of the main motivations of recent nuclear reaction and nuclear transmutation studies of radioactive waste. The authors show the enhancement of proton rich isotope production using incomplete fusion mechanism on weakly bound nuclei using the incomplete fusion mechanism by the inverse kinematics technique, in which a radioactive beam of Palladium bombards a proton/deuteron target.

Published
2018

46. Role of the Δ Resonance in the Population of a Four-Nucleon State in the Fe56→Fe54 Reaction at Relativistic Energies

Author

C. Louchart, I. Kojouharov, G. de Angelis, B. Bruyneel, A. Maj, J. Gerl, W. Korten, T. Alexander, D. S. Judson, M. D. Salsac, L. J. Harkness-Brennan, M. Reese, S. Pietri, H. Schaffner, J. J. Valiente Dobon, M. Labiche, Zena Patel, Dirk Rudolph, M. Lettmann, Luis Sarmiento, C. M. Shand, A. Pullia, P. H. Regan, H. Pai, Zs. Dombrádi, J. Eberth, A. Gadea, R. M. Pérez-Vidal, P. Désesquelles, Helmut Weick, B. Birkenbach, A. Jungclaus, D. Mengoni, C. Michelagnoli, Pavel Golubev, E. Wilson, I. Burrows, M. L. Cortés, D. R. Napoli, N. Lalović, D. M. Cullen, L. Charles, Herbert Hess, E. Merchan, Begoña Quintana, Eric Clément, T. Habermann, D. Ralet, T. Arici, G. Rainovski, N. Kurz, M. Górska, Oliver Wieland, Vicente González, P. Boutachkov, Raymond J. Carroll, Zs. Podolyák, P. Reiter, F. Ameil, C. Lizarazo, F. C. L. Crespi, Enrique Sanchis, Norbert Pietralla, Ch Stahl, and D. Mahboub

Subjects
Quark, Physics, education.field_of_study, Proton, 010308 nuclear & particles physics, Nuclear Theory, Population, General Physics and Astronomy, 7. Clean energy, 01 natural sciences, Resonance (particle physics), Momentum, Metastability, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, education, Ground state
Abstract

The 54Fe nucleus was populated from a 56Fe beam impinging on a Be target with an energy of E=A ¼ 500 MeV. The internal decay via γ-ray emission of the 10þ metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the 56Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of 54Fe, suggesting that it was populated via the decay of the Δ0 resonance into a proton. This process allows the population of fournucleon states, such as the observed isomer. Therefore, it is concluded that the observation of this 10þ metastable state in 54Fe is a consequence of the quark structure of the nucleons.

Published
2016

47. Role of the Δ Resonance in the Population of a Four-Nucleon State in the $^{56}$Fe → $^{54} $Fe Reaction at Relativistic Energies

Author

Zs, Podolyák, C M, Shand, N, Lalović, J, Gerl, D, Rudolph, T, Alexander, P, Boutachkov, M L, Cortés, M, Górska, I, Kojouharov, N, Kurz, C, Louchart, E, Merchán, C, Michelagnoli, R M, Pérez-Vidal, S, Pietri, D, Ralet, M, Reese, H, Schaffner, Ch, Stahl, H, Weick, F, Ameil, G, de Angelis, T, Arici, R, Carroll, Zs, Dombrádi, A, Gadea, P, Golubev, M, Lettmann, C, Lizarazo, D, Mahboub, H, Pai, Z, Patel, N, Pietralla, P H, Regan, L G, Sarmiento, O, Wieland, E, Wilson, B, Birkenbach, B, Bruyneel, I, Burrows, L, Charles, E, Clément, F C L, Crespi, D M, Cullen, P, Désesquelles, J, Eberth, V, González, T, Habermann, L, Harkness-Brennan, H, Hess, D S, Judson, A, Jungclaus, W, Korten, M, Labiche, A, Maj, D, Mengoni, D R, Napoli, A, Pullia, B, Quintana, G, Rainovski, P, Reiter, M D, Salsac, E, Sanchis, J J, Valiente Dóbon, 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), 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), AGATA, 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 and Astronomy (all), gamma-ray spectroscopy, Subatomic Physics, Nuclear Theory, isomer decay, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, relativistic projectile fragmentation
Abstract

The ^{54}Fe nucleus was populated from a ^{56}Fe beam impinging on a Be target with an energy of E/A=500 MeV. The internal decay via γ-ray emission of the 10^{+} metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the ^{56}Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of ^{54}Fe, suggesting that it was populated via the decay of the Δ^{0} resonance into a proton. This process allows the population of four-nucleon states, such as the observed isomer. Therefore, it is concluded that the observation of this 10^{+} metastable state in ^{54}Fe is a consequence of the quark structure of the nucleons.

Published
2016

48. Low-lying isovector2+valence-shell excitations ofPo212

Author

A. Astier, P. Scholz, J. Litzinger, A. Dewald, Norbert Pietralla, V. Werner, V. Karayonchev, W. Witt, Thomas Braunroth, M. Djongolov, J. Jolie, M. L. Cortés, R. Stegmann, C. Müller-Gatermann, P. Petkov, Marcus Scheck, G. Rainovski, P. Thöle, D. Wölk, K. A. Gladnishki, C. Fransen, P. Van Isacker, A. Hennig, C. Stahl, D. Kocheva, and A. Blazhev

Subjects
Physics, Isovector, 010308 nuclear & particles physics, Nuclear Theory, SHELL model, 01 natural sciences, Symmetry (physics), Excited state, 0103 physical sciences, Quadrupole, Atomic physics, 010306 general physics, Spectroscopy, Valence electron, Beam (structure)
Abstract

We present the results from an experiment dedicated to search for quadrupole-collective isovector valence-shell excitations, states with so-called mixed proton-neutron symmetry (MSS), of $^{212}\mathrm{Po}$. This nucleus was studied in an $\ensuremath{\alpha}\text{-transfer}$ reaction. The lifetimes of two short-lived excited states, candidates for the one-phonon MSS, were determined by utilizing the Doppler shift attenuation method. The experimental results are in qualitative agreement with a simple $\text{single-}j$ shell model calculation, which, together with the observed lack of quadrupole collectivity, indicates that the isovector nature of low-lying states is a property of the leading single-particle valence shell configuration.

Published
2016

49. Inelastic scattering of $^{72,74}Ni$ off a proton target

Author

J.-Y. Roussé, Tadaaki Isobe, David Steppenbeck, R. Lozeva, T. Sumikama, Masaki Sasano, Zs. Dombradi, A. Gillibert, Satoshi Takeuchi, Zhengyu Xu, K. Hadynska-Klek, S. Franchoo, E. C. Pollacco, F. Château, E. Sahin, T. Miyazaki, Satoru Momiyama, Jenny Lee, Zena Patel, C. Santamaria, Hidetada Baba, Daisuke Suzuki, D. Calvet, C. Péron, Z. Korkulu, Yuya Kubota, G. Authelet, Alessandra Corsi, H. Wang, C. M. Shand, J. M. Gheller, M. Matsushita, Pieter Doornenbal, S. Nishimura, M. Lettmann, A. Gottardo, F. Giacoppo, K. Matsui, V. Werner, K. Yoneda, Zs. Vajta, P. A. Söderström, C. Louchart, Shuichi Ota, A. Delbart, R. Taniuchi, M. L. Cortés, Megumi Niikura, Tomohiro Uesaka, F. Browne, Jin Wu, L. X. Chung, L. Olivier, Hideaki Otsu, I. Stefan, Tohru Motobayashi, V. Lapoux, A. Obertelli, Yoshiaki Shiga, Hiroyoshi Sakurai, Shoko Koyama, Norbert Pietralla, Alan Peyaud, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut 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), 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), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg (UNISTRA)-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
History, Proton, Spectrometer, Isotope, 010308 nuclear & particles physics, Fission, Gamma ray, chemistry.chemical_element, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Computer Science Applications, Education, Ion, Nuclear physics, chemistry, 0103 physical sciences, Beryllium, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

International audience; Inelastic scattering of (72,74)Ni off a proton target was performed at RIBF, RIKEN, Japan. The isotopes were produced by the fission of (238)U on a thick Beryllium target and were then selected and identified on an event-by-event basis using the BigRIPS separator. Selected isotopes were focused onto the liquid hydrogen target of the MINOS device and gamma rays from the reactions were measured with the DALI2 array. The energy of the ions in the middle of the target was 213 MeV/u. Outgoing particles were identified using the ZeroDegree spectrometer. Here, we report on the current status of the data analysis and preliminary results for the proton inelastic scattering cross sections for both isotopes.

Published
2015

50. Isomeric Ratios in 206Hg

Author

I. Kojouharov, W. Gelletly, H. J. Wollersheim, Raymond J. Carroll, Zs. Podolyák, Claes Fahlander, W. Korten, Jnaneswari Gellanki, S. Pietri, Pavel Golubev, M. L. Cortés, M. A. Bentley, Pushpendra Singh, A. Givechev, P. Boutachkov, G. Guastalla, E. Merchan, Luis Sarmiento, T. Habermann, C. Stahl, R. Wood, O. Wieland, Dirk Rudolph, A. Jungclaus, A. Gadea, P. M. Walker, Th Moeller, Anna Wendt, P. Thoele, P. Reiter, O. Stezowksi, F. Ameil, M. Lettmann, N. Goel, K. Moschner, R. Stegmann, M. Hackstein, P. H. Regan, C. Louchart, E. Gregor, J. Gerl, N. Lalović, H. Schaffner, D. Ralet, Norbert Pietralla, M. Górska, M. Reese, S. K. Mandal, A. Gottardo, M. Bowry, N. Kurz, C. Bauer, T. Alexander, C. Lizarazo, T. Arici, Jan Taprogge, Shaji Kumar, A. Blazhev, E. Wilson, Z. Patel, C. Michelagnoli, D. Bazzacco, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, General Physics and Astronomy, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, gamma-ray spectroscopy, Fragmentation (mass spectrometry), relativistic Coulomb excitation, 0103 physical sciences, Subatomic Physics, Gamma spectroscopy, AGATA, PreSPEC-AGATA, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

International audience; 206Hg was populated in the fragmentation of an E∕A = 1 GeV 208Pb beam at GSI. It was part of a campaign to study nuclei around 208Pb via relativistic Coulomb excitation. The observation of the known isomeric states confirmed the identification of the fragmentation products. The isomeric decays were also used to prove that the correlations between beam identification detectors and the AGATA γ-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.

Published
2015

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