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1. Three-quasiparticle isomers in odd-even Pm159,161 : Calling for modified spin-orbit interaction for the neutron-rich region

Author

Tetsuro Komatsubara, Toshiyuki Kubo, Long-Jun Wang, I. Kojouharov, H. Baba, Y. F. Fang, Giuseppe Lorusso, Jan Taprogge, F. L. Bello Garrote, I. Nishizuka, Hirofumi Watanabe, Masafumi Matsushita, Shunji Nishimura, S. Inabe, A. Gottardo, H. Schaffner, Z. H. Li, Motoki Kobayashi, L. Sinclair, F. Browne, G. Benzoni, Nori Aoi, M. Tanaka, D. Kameda, E. Sahin, Gary Simpson, Cui Juan Lv, Zhengyu Xu, Toshiyuki Sumikama, Guillaume Gey, Shintaro Go, Chang-Bum Moon, P. Doornenbal, Hiroyuki Takeda, Zena Patel, T. Isobe, Hiroshi Suzuki, Atsuko Odahara, R. Yokoyama, N. Kurz, Naoki Fukuda, Stephen Rice, Zs. Vajta, Yang Sun, Hiroyoshi Sakurai, Shin'ichiro Michimasa, P. A. Söderström, Ayumi Yagi, Eiji Ideguchi, Yan Xin Liu, István Kuti, K. Kobayashi, R. Daido, Jinguang Wu, and Hiroki Nishibata

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, Spin–orbit interaction, 01 natural sciences, Ion, 0103 physical sciences, Quasiparticle, Neutron, Atomic physics, 010306 general physics, Spectroscopy, Nucleon
Abstract

Neutron-rich Pm ( Z = 61 ) isotopes were studied by delayed γ -ray spectroscopy at RIBF, RIKEN Nishina Center using the in-flight fission of a 345 MeV/nucleon U 238 beam. A cluster-type Ge detector array, EURICA, was used to measure the delayed γ rays from stopped ions. Isomeric γ decays were observed in Pm 159 and Pm 161 with half-lives of 4.97(12) μ s and 0.79(4) μ s , respectively. Level schemes for Pm 159 and Pm 161 were constructed in this study. The isomeric states of Pm 159 and Pm 161 could be interpreted as two quasiparticle excitations of neutrons with the configurations of ν ( 7 / 2 [ 633 ] ⊗ 5 / 2 [ 523 ] ) and ν ( 7 / 2 [ 633 ] ⊗ 1 / 2 [ 521 ] ) , respectively. They are analogous to the isomers that have been observed systematically in other even-mass N = 98 and N = 100 isotones in this region. A projected shell model calculation was performed and it reproduced the order of three-quasiparticle states only if new Nilsson parameters with an N -dependent spin-orbit interaction were used. This work demonstrates that the strength of spin-orbit interactions in standard Nilsson parameters needs to be modified to study the properties of neutron-rich rare-earth nuclei around A = 165 , and provides new evidence supporting the existence of the deformed N = 98 subshell gap in odd-mass nuclei for the first time.

Published
2021

2. Persistence of the Z=28 shell gap in A=75 isobars: Identification of a possible (1/2−) μs isomer in Co75 and β decay to Ni75

Author

Hiroki Nishibata, A. I. Morales, Hirofumi Watanabe, Shin-Ichiro Nishimura, Megumi Niikura, Daisuke Suzuki, H. S. Jung, V. Werner, Ryo Taniuchi, D. Sohler, D. R. Napoli, Jan Taprogge, T. Isobe, N. Kurz, I. Kojouharov, Toshiyuki Sumikama, Jinguang Wu, P. A. Söderström, Ayumi Yagi, I. Matea, P. Morfouace, P. R. John, S. Franchoo, Shigeru Kubono, S. Escrig, F. Naqvi, Alfredo Poves, Atsuko Odahara, K. Matsui, Giuseppe Lorusso, H. Baba, Hiroyoshi Sakurai, Zhengyu Xu, Z. H. Li, E. Sahin, P. Doornenbal, D. Mengoni, Zs. Vajta, H. Schaffner, K. Yoshinaga, I. Stefan, F. Browne, and Guillaume Gey

Subjects
Physics, Proton, 010308 nuclear & particles physics, Center (category theory), Nuclear structure, Nuclear isomer, 7. Clean energy, 01 natural sciences, Spectral line, Nuclear physics, Nucleosynthesis, Excited state, 0103 physical sciences, Isobar, 010306 general physics
Abstract

Background: The evolution of shell structure around doubly-magic exotic nuclei is of great interest in nuclear physics and astrophysics. In the `south-west' region of $^{78}$Ni, the development of deformation might trigger a major shift in our understanding of explosive nucleosynthesis. To this end, new spectroscopic information on key close-lying nuclei is very valuable. Purpose: We intend to measure the isomeric and $\beta$ decay of $^{75}$Co, with one proton- and two neutron-holes relative to $^{78}$Ni, to access new nuclear structure information in $^{75}$Co and its $\beta$-decay daughters $^{75}$Ni and $^{74}$Ni. Methods: The nucleus $^{75}$Co is produced in relativistic in-flight fission reactions of $^{238}$U at the Radioactive Ion Beam Factory (RIBF) in the RIKEN Nishina Center. Its isomeric and $\beta$ decay are studied exploiting the BigRIPS and EURICA setups. Results: We obtain partial $\beta$-decay spectra for $^{75}$Ni and $^{74}$Ni, and report a new isomeric transition in $^{75}$Co. The energy ($E_{\gamma}=1914(2)$ keV) and half-life ($t_{1/2}=13(6)$ $\mu$s) of the delayed $\gamma$ ray lend support for the existence of a $J^{\pi}=(1/2^-)$ isomeric state at 1914(2) keV. A comparison with PFSDG-U shell-model calculations provides good account for the observed states in $^{75}$Ni, but the first calculated $1/2^-$ level in $^{75}$Co, a prolate $K=1/2$ state, is predicted about 1 MeV below the observed $(1/2^-)$ level. Conclusions: The spherical-like structure of the lowest-lying excited states in $^{75}$Ni is proved. In the case of $^{75}$Co, the results suggest that the dominance of the spherical configurations over the deformed ones might be stronger than expected below $^{78}$Ni. Further experimental efforts to discern the nature of the $J^{\pi}=(1/2^-)$ isomer are necessary.

Published
2021

3. Observation of new neutron-rich isotopes in the vicinity of Zr 110

Author

Takashi Kubo, Zena Patel, H. Takeda, Eiji Ideguchi, F. Didierjean, G. Lorusso, Zhengyu Xu, T. Isobe, Raymond J. Carroll, Jan Taprogge, Y. F. Fang, Naoki Fukuda, Zs. Podolyák, Kenichi Yoshida, R. Daido, O. Wieland, Toshiyuki Sumikama, R. Lozeva, H. Baba, Z. H. Li, F. Browne, Ayumi Yagi, Hiroyoshi Sakurai, D. Kameda, Shin-Ichiro Nishimura, Guillaume Gey, Hiroshi Suzuki, P. Doornenbal, S. Lalkovski, P. H. Regan, Atsuko Odahara, Stephen Rice, L. Sinclair, Momoko Tanaka, I. Nishizuka, Nobuyuki Chiga, Gary Simpson, Y. Shimizu, Alison Bruce, P. A. Söderström, Naohito Inabe, Hirofumi Watanabe, Hiroki Nishibata, Oliver J. Roberts, V. Werner, Jin Wu, RIKEN Nishina Center for Accelerator-Based Science, University of Tokyo, Japan Society for the Promotion of Science, National Research Foundation of Korea, Science and Technology Facilities Council (UK), Department of Energy (US), Federal Ministry of Education and Research (Germany), Ministerio de Ciencia e Innovación (España), Department for Business, Energy and Industrial Strategy (UK), National Measurement System (UK), 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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Isotope, Spectrometer, 010308 nuclear & particles physics, Fission, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Time of flight, 0103 physical sciences, Nuclear Reactions, Physics::Accelerator Physics, Neutron, 010306 general physics, Nucleon, Nuclear Experiment, Beam (structure)
Abstract

5 pags., 3 figs., 2 tabs., Neutron-rich radioactive isotope (RI) beams in the vicinity of Zr110 were produced using the in-flight fission of a 345-MeV/nucleon U238 beam at the RIKEN Radioactive Isotope Beam Factory. The RI beams were separated in flight by the large-acceptance two-stage fragment separator BigRIPS. Isotopes were clearly identified in a low-background particle-identification plot, which was obtained from the measurements of time of flight, magnetic rigidity, and energy loss using beam-line detectors placed in the BigRIPS separator and the ZeroDegree spectrometer. Nine new isotopes, Br101, Kr102, Rb105,106, Sr108, Y110,111, Zr114, and Nb117, are reported for the first time, with their measured production cross sections compared with the extrapolations of lighter isotopes down to the femtobarn regime., This experiment was carried out at the RIBF operated by the RIKEN Nishina Center, and the Center for Nuclear Study, the University of Tokyo. The authors acknowledge the RIBF accelerator staffs for their efforts in delivering an intense 238U beam. This work was supported by JSPS KAKENHI Grants No. 2301752, No. 24740188, No. 25247045, No. 26800117, and No. 16K17680, NRF Grant No. 2016K1A3A7A09005575, STFC Grants No. ST/J000132/1, No. ST/J000051/1, No. ST/K502431/1, No. ST/L005743/1, No. ST/P003885/1, No. ST/P003982/1, and No. ST/P005314/1, DOE Grant No. DE-FG02-91ER 40609, BMBF Grant No. 05P19RDFN1, and Spanish Ministerio de Ciencia e Innovación under Contracts No. FPA2009- 13377-C02 and No. FPA2011-29854-C04. P.H.R. and G.L. acknowledge additional support from the UK Department for Business, Energy and Industrial Strategy (BEIS) via funding for the UK National Measurement System. P.-A.S. was financed by the RIKEN Foreign Postdoctoral Researcher Program

Published
2021

4. Nuclear structure of Te isotopes beyond neutron magic number N=82

Author

Y. Shimizu, Giuseppe Lorusso, F. L. Bello Garrote, I. Nishizuka, T. Isobe, Chang-Bum Moon, A. Jungclaus, S. Morimoto, Naohito Inabe, Y. F. Fang, Zs. Vajta, Hiroshi Watanabe, Roman Gernhäuser, C. S. Lee, Hiroshi Suzuki, Toshiyuki Sumikama, Shunji Nishimura, H. Schaffner, M. Si, D. Mücher, Hiroyuki Takeda, Daichi Murai, F. Browne, Hiroki Nishibata, Atsuko Odahara, Anna Wendt, J. M. Daugas, Guillaume Gey, L. Sinclair, Hiroyoshi Sakurai, I. Kojouharov, P. A. Söderström, Ayumi Yagi, S. Bönig, Byung-Sik Hong, Gary Simpson, R. Orlandi, Younghun Kwon, A. Montaner-Pizá, Stephen Rice, D. Kameda, J. M. Keatings, Eiji Ideguchi, Rin Yokoyama, K. Moschner, A. Gargano, S. Ilieva, Jan Taprogge, K. Yoshinaga, Hyo Soon Jung, B. Moon, R. Daido, Zena Patel, D. S. Ahn, P. Doornenbal, Jin Wu, H. Naïdja, K. Tshoo, N. Kurz, K. Steiger, Naoki Fukuda, Megumi Niikura, P. Lee, F. Didierjean, Tetsuro Komatsubara, Toshiyuki Kubo, T. Kröll, R. Lozeva, F. Drouet, Z. H. Li, H. Baba, Zhengyu Xu, T. Ishigaki, RIKEN Nishina Center for Accelerator-Based Science, University of Tokyo, Institute for Basic Science (South Korea), National Research Foundation of Korea, Ministerio de Economía y Competitividad (España), Japan Society for the Promotion of Science, National Research, Development and Innovation Office (Hungary), 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), 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 Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Nuclear Theory, Nuclear structure, Nuclear Structure, 7. Clean energy, 01 natural sciences, Nuclear physics, Fragmentation (mass spectrometry), Excited state, 0103 physical sciences, Neutron, 010306 general physics, Nucleon, Nuclear Experiment, Beam (structure), Magic number (physics)
Abstract

15 pags., 10 figs., 4 tabs., Newly observed decay schemes of the nuclei Sb137 and Sb138 are reported. The neutron-rich Sb isotopes were produced by the in-flight fragmentation of a U238 primary beam with an energy of 345 MeV/nucleon. Several new excited states of Te137 with tentatively assigned spin-parities of (5/2-), (9/2-), and (7/2) have been established which play an important role in the evolution of neutron levels beyond N=82. The study of the ß decay of Sb138 led to a considerable extension of the level scheme of Te138 including the identification of several nonyrast states. The structure of Te137 and Te138 is discussed on the basis of large-scale shell-model calculations performed using two different effective interactions., This work was carried out at the RIBF operated by RIKEN Nishina Center and CNS, University of Tokyo. Part of the WAS3ABi was supported by the Rare Isotope Science Project (RISP) of the Institute for Basic Science (IBS) funded by the Ministry of Science, ICT and Future Planning (MSIP) and National Research Foundation (NRF) of the Republic of Korea (Grant No. 2013M7A1A1075764). This research was supported by NRF of the Republic of Korea (Grants No. 2019R1A6A3A03031564 and No. 2018R1A5A1025563), IBS of the Republic of Korea (Grants No. IBS-R031-D1 and No. IBS-R031-Y1), the Spanish Ministerio de Economía y Competitividad (Grant No. FPA2017-84756-C4-2-P), and JSPS KAKENHI of Japan (Grant No. 25247045). The support from FR-JP LIA is also acknowledged. C.S.L. acknowledges the support from NRF of the Republic of Korea (Grants No. 2017M2A2A6A02071071 and No. 2016R1D1A1A09917463). Z.V. acknowledges the supports from the National Research, Development and Innovation Fund of Hungary, financed under the K18 funding scheme with Project No. K128947 and by the European Regional Development Fund (Grant No. GINOP-2.3.3-15-2016- 00034), as well as by the National Research, Development and Innovation Office NKFIH (Grant No. PD 124717).

Published
2021

5. Impact of shell evolution on Gamow-Teller β decay from a high-spin long-lived isomer in 127Ag

Author

Hirofumi Watanabe, Young-Ki Kim, Chang-Bum Moon, A. Jungclaus, Younghun Kwon, A. Montaner-Pizá, Anna Wendt, Shunji Nishimura, Hiroshi Suzuki, F. Naqvi, Megumi Niikura, K. Yoshinaga, Ayumi Yagi, Z. H. Li, G. J. Lane, Giuseppe Lorusso, Hyo Soon Jung, F. Browne, D. Kameda, Hiroki Nishibata, Gary Simpson, P. Doornenbal, K. Steiger, Guillaume Gey, T. Isobe, F. G. Kondev, I. Kojouharov, Toshiyuki Sumikama, Zs. Vajta, R. Orlandi, Toshiyuki Kubo, Hiroyuki Takeda, Naohito Inabe, Atsuko Odahara, Jin Wu, G. D. Kim, H.K. Wang, Jan Taprogge, Roman Gernhäuser, G. Benzoni, F. C. L. Crespi, H. Schaffner, K. Moschner, H. Baba, Naoki Fukuda, Zs. Podolyák, K. Y. Chae, N. Kurz, Zhengyu Xu, P. A. Söderström, Daiki Nishimura, Hiroyoshi Sakurai, Zena Patel, Cenxi Yuan, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Ministry of Science and Technology (South Korea), Department of Energy (US), National Research Foundation of Korea, Ministerio de Economía y Competitividad (España), Federal Ministry of Education and Research (Germany), Japan Society for the Promotion of Science, National Natural Science Foundation of China, National Key Research and Development Program (China), and Science and Technology Facilities Council (UK)

Subjects
Nuclear and High Energy Physics, QC1-999, Nuclear Theory, Shell (structure), Shell evolution, Ag, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, decay, Gamow-Teller, 0103 physical sciences, medicine, Physics::Atomic and Molecular Clusters, Neutron, 010306 general physics, Spin (physics), Physics, 010308 nuclear & particles physics, Gamow-Teller β decay, Parity (physics), 127Ag, ddc, Isomer, medicine.anatomical_structure, 13. Climate action, Atomic nucleus, 127 Ag, Atomic physics, Radioactive isotope beam, Nucleus, Excitation
Abstract

6 pags., 4 figs., 2 tabs., The change of the shell structure in atomic nuclei, so-called “nuclear shell evolution”, occurs due to changes of major configurations through particle-hole excitations inside one nucleus, as well as due to variation of the number of constituent protons or neutrons. We have investigated how the shell evolution affects Gamow-Teller (GT) transitions that dominate the β decay in the region below 132Sn using the newly obtained experimental data on a long-lived isomer in 127Ag. The T1/2=67.5(9) ms isomer has been identified with a spin and parity of (27/2+) at an excitation energy of 1942−20+14 keV, and found to decay via an internal transition of an E3 character, which competes with the dominant β-decay branches towards the high-spin states in 127Cd. The underlying mechanism of a strong GT transition from the 127Ag isomer is discussed in terms of configuration-dependent optimization of the effective single-particle energies in the framework of a shell-model approach., Part of the WAS3ABi was supported by the Rare Isotope Science Project which is funded by MSIP and NRF of Korea. This work was supported by the Priority Centers Research Program in Korea (2009-0093817), OTKA contract number K100835, the U.S. DOE, Office of Nuclear Physics (Contract No. DE-AC02-06CH11357), NRF2016R1A5A1013277 and NRF-2013M7A1A1075764, the Spanish Ministerio de Economía y Competitividad under contract FPA2017- 84756-C4-2-P, the European Commission through the Marie Curie Actions call FP7-PEOPLE-2011-IEF (Contract No. 300096), German BMBF under Contract No: 05P12PKFNE, JSPS KAKENHI Grant No. 24740188 and 25247045, the National Natural Science Foundation of China (Nos. 11505302, 11575112, 11775316), the National Key Program for S&T Research and Development (No. 2016YFA0400501), and STFC (UK).

Published
2021

6. Evolution of proton single-particle states in neutron-rich Sb isotopes beyond N=82

Author

A. Jungclaus, Y. Shimizu, H. Schaffner, Hiroshi Suzuki, T. Isobe, I. Kojouharov, Hiroshi Watanabe, G. D. Kim, J. M. Daugas, Hiroki Nishibata, Jinguang Wu, Hiroyoshi Sakurai, D. Kameda, Toshiyuki Kubo, Shunji Nishimura, A. Gargano, Gary Simpson, P. Doornenbal, Atsuko Odahara, H. Baba, K. Moschner, Roman Gernhäuser, F. Browne, Z. H. Li, Z Vajta, Ayumi Yagi, Naohito Inabe, S. Bönig, Marcus Scheck, Guillaume Gey, T. Kröll, K. Yoshinaga, S. Ilieva, N. Kurz, Jan Taprogge, Naoki Fukuda, K. Steiger, Hyo Soon Jung, R. Orlandi, J. M. Keatings, Young-Ki Kim, P. A. Söderström, Younghun Kwon, A. Montaner-Pizá, Giuseppe Lorusso, Anna Wendt, D. Mücher, Toshiyuki Sumikama, Hiroyuki Takeda, H. Naïdja, Zhengyu Xu, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ILL, RIKEN Nishina Center for Accelerator-Based Science, Ministerio de Economía y Competitividad (España), Science and Technology Facilities Council (UK), and National Research, Development and Innovation Office (Hungary)

Subjects
Physics, Proton, Isotope, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 7. Clean energy, 01 natural sciences, Beta decay, Nuclear physics, Neutron number, Excited state, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Excitation
Abstract

11 pags., 8 figs., 2 tabs., The β decay of the semimagic Sn isotopes Sn136,137,138 has been studied at the Radioactive Isotope Beam Factory at the RIKEN Nishina Center. The first experimental information on excited states was obtained for Sb137 while, in the case of Sb136, the established excitation scheme could be extended by ten previously unidentified levels. In the decay of the most-neutron-rich isotope Sn138, two γ rays were observed for the first time. The new experimental results, in combination with state-of-the-art shell-model calculations, provide the first information with respect to the evolution of the 0g7/2 and 1d5/2 proton single-particle states with increasing neutron number beyond N=84., We thank the staff of the RIKEN Nishina Center accelerator complex for providing high-intensity beams to the experiment. This work was supported by the Spanish Ministerio de Ciencia e Innovación under contracts FPA2014-57196-C5-4-P and FPA2017-84756-C4-2-P and the UK Science and Technology Facilities Council under Grant No. ST/P005101/1. Zs.V. was supported by the European Regional Development Fund (Contract No. GINOP-2.3.3- 15-2016-00034), the National Research Development and Innovation Fund of Hungary (Grant No. K128947), and by RIKEN as short-term International Program Associate.

Published
2020

7. Determination of beta-delayed neutron emission probability limits of rhodium isotopes by gamma-ray spectroscopy

Author

Shunji Nishimura, Naohito Inabe, Roman Gernhäuser, A. Boso, Z. H. Li, T. Isobe, Toshiyuki Kubo, H. Baba, F. G. Kondev, H. Schaffner, Megumi Niikura, Gary Simpson, G. Benzoni, F. C. L. Crespi, Hirofumi Watanabe, Zs. Vajta, Anna Wendt, Y. Shimizu, Atsuko Odahara, Jinguang Wu, A. Jungclaus, Hiroyoshi Sakurai, Hiroshi Suzuki, R. Orlandi, I. Kajouharov, Hyo Soon Jung, Zhengyu Xu, F. Browne, K. Yoshinaga, Jan Taprogge, Toshiyuki Sumikama, Guillaume Gey, Hiroyuki Takeda, P. H. Regan, G. J. Lane, Giuseppe Lorusso, Zena Patel, G. D. Kim, K. Moschner, S. Shibagaki, Bradley S. Meyer, R. Shearman, F. Naqvi, D. Kameda, Ayumi Yagi, P. Doornenbal, P. Schury, K. Steiger, Toshitaka Kajino, Young-Ki Kim, P. A. Söderström, Younghun Kwon, A. Montaner-Pizá, K. Y. Chae, N. Kurz, Naoki Fukuda, Zs. Podolyák, Hiroki Nishibata, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Science and Technology Facilities Council (UK), Department for Business, Energy and Industrial Strategy (UK), National Measurement System (UK), and Department of Energy (US)

Subjects
Paper, History, Fission, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Education, Nuclear physics, 0103 physical sciences, Gamma spectroscopy, Nuclear drip line, Nuclide, 010306 general physics, Nuclear Experiment, Physics, Isotope, 010308 nuclear & particles physics, 3. Good health, Computer Science Applications, ddc, chemistry, Physics::Accelerator Physics, Beryllium, Delayed neutron
Abstract

9 pags., 5 figs., 5 tabs. -- 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK, The decay of five neutron-heavy rhodium isotopes were studied at the Radioactive Isotope Beam Factory (RIBF) Facility at the RIKEN Nishina Center after relativistic fission of 238U beam on a thick beryllium target. Previously unknown associated gamma-ray decay energies are reported for each nuclide, and through evaluating the intensity of the 2+ → 0+ E2 transition in the even-even palladium daughter nuclei, 120,122,124Pd, from the beta-tagged gamma-ray spectra an upper or lower limit of beta-delayed neutron emission is deduced for each nuclei. A general, expected trend of increasing Pn is observed in the direction of the neutron drip line., This work was partially supported by the STFC UK (grant numbers ST/L005743/1 and ST/P005314) and UK Department of Business, Energy and Industrial Strategy (BEIS) via the National Measurement System. RS thanks the Nuclear Decommissioning Authority (NDA) for the award of an NDA Bursary. FGK acknowledges funding by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

Published
2019

8. Proton Shell Evolution below Sn132 : First Measurement of Low-Lying β -Emitting Isomers in Ag123,125

Author

Shudong Zhang, Naoki Fukuda, Zs. Podolyák, Shunji Nishimura, Yan-Lin Ye, T. Isobe, C. Y. Niu, Hiroki Nishibata, Xiaocan Li, Jin Wu, Ziyang Chen, Y. Jin, Toshiyuki Kubo, K. Moschner, D.X. Jiang, H.K. Wang, K. Yoshinaga, Chenyuan Li, K. Y. Chae, Jian-Ling Lou, Da Luo, G. Benzoni, A. Jungclaus, Hirofumi Watanabe, Ayumi Yagi, N. Kurz, Hiroshi Suzuki, I. Kojouharov, Hiroyoshi Sakurai, Atsuko Odahara, G. D. Kim, Young-Ki Kim, H. Y. Wu, Younghun Kwon, A. Montaner-Pizá, H. Baba, Roman Gernhäuser, G. J. Lane, Giuseppe Lorusso, Zhengyu Xu, Toshiyuki Sumikama, Hiroyuki Takeda, C. Xu, Naohito Inabe, Anna Wendt, Zs. Vajta, H. Schaffner, F. C. L. Crespi, Gary Simpson, F. G. Kondev, C. G. Wu, Z. H. Li, F. Naqvi, D. Kameda, P. A. Söderström, P. Doornenbal, K. Steiger, X. Wang, Zena Patel, F. Browne, H. S. Jung, Cenxi Yuan, Megumi Niikura, Jan Taprogge, Guillaume Gey, R. Orlandi, C. G. Wang, and Hui Hua

Subjects
Physics, Atomic orbital, Isotope, 0103 physical sciences, Magnetic monopole, General Physics and Astronomy, Atomic physics, 010306 general physics, Spectroscopy, 7. Clean energy, 01 natural sciences
Abstract

The β-delayed γ-ray spectroscopy of neutron-rich 123;125Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN and the long-predicted 1/2¯ β-emitting isomers in 123;125Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2+ and 1/2¯ levels is extended in Ag isotopes up to N = 78, providing a clear signal for the reduction of the Z = 40 subshell gap in Ag towards N = 82. Shellmodel calculations with the state-of-the-art VMU plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in 123;125Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z = 40 subshell gap. The observed inversion of the single particle levels around 123Ag can be well interpreted in terms of the monopole shift of the π1g9/2 orbitals mainly caused by the increasing occupation of ʋ1h11/2 orbitals.

Published
2019

9. Accelerate the analysis and optimization of lamellar BCP process using machine learning

Author

Johann Foucher, Alexandre Dervillé, Sergio Martinez, Xavier Chevalier, Guillaume Gey, Julien Baderot, and Guilhem Bernard

Subjects
Measure (data warehouse), Computer science, business.industry, Process (computing), Image processing, Machine learning, computer.software_genre, Data-driven, Set (abstract data type), Process control, Process optimization, Process window, Artificial intelligence, business, computer
Abstract

This paper presents how to use machine learning to accelerate the development of lamellar block copolymer process. The first part introduces an automated algorithm to measure lamellar CD-SEM images oriented to allow fast images screening, identify and select the most relevant chemical composition. The second part is the use of machine learning in the process development which is a data driven approach. This part is also divided in two sections, the first one for the prediction of the process, where having a set of experiments in a process window, a model is created so that the outcome from is estimated from different parameters. The second part is the estimation of the process window. These tools are oriented to assist process engineers in the process optimization which must be driven under expert supervision.

Published
2019

10. Using machine learning technology to accelerate the development of plasma etching processes

Author

Guillaume Gey, Sergio Martinez, Alexandre Dervillé, Julien Baderot, Guilhem Bernard, and Johann Foucher

Subjects
Focus (computing), Computer science, business.industry, SIGNAL (programming language), Stability (learning theory), Machine learning, computer.software_genre, Pipeline (software), Field (computer science), Robustness (computer science), Feature (machine learning), Process control, Artificial intelligence, business, computer
Abstract

The latest advances in Machine Learning (ML) produce results with unprecedented accuracy, and could signal a new era in the smart manufacturing field. We propose a framework designed to work alongside experts: learning from them and optimizing their knowledge. This framework must be considered as a tool to assist the experts in their daily work. The user creates a measurement recipe which includes an example of the feature as well as the measurements placed by the process engineer. Grouping the measurement recipes of the same object in an entity collection allows the user to train a machine learning recipe which includes a deformation model to handle variations in structure and contrast. The new images are analyzed following the machine learning pipeline which includes the detection of features, repositioning, measurement, quality evaluation and finally the results of measurement are given to the user. We discuss the pipeline and we focus on the metrics to validate the machine learning recipe, providing quantitative results for stability and robustness to variations.

Published
2019

11. New isomers in $^{125}$Pd$_{79}$ and $^{127}$Pd$_{81}$: Competing proton and neutron excitations in neutron-rich palladium nuclides towards the $N = 82$ shell closure

Author

Gary Simpson, Naohito Inabe, Hirofumi Watanabe, G. D. Kim, Chang-Bum Moon, A. Jungclaus, Ayumi Yagi, Megumi Niikura, Toshiyuki Sumikama, T. Isobe, Hiroshi Suzuki, Toshiyuki Kubo, Hyo Soon Jung, Shunji Nishimura, Hiroyuki Takeda, Atsuko Odahara, Jan Taprogge, G. Benzoni, F. C. L. Crespi, K. Yoshinaga, H. Baba, G. J. Lane, Giuseppe Lorusso, F. Browne, F. G. Kondev, I. Kojouharov, Guillaume Gey, H.K. Wang, Roman Gernhäuser, R. Orlandi, Z. H. Li, Hiroki Nishibata, Anna Wendt, H. Schaffner, Zs. Vajta, Zhengyu Xu, Young-Ki Kim, Younghun Kwon, A. Montaner-Pizá, Hiroyoshi Sakurai, Zena Patel, Daiki Nishimura, Yang Sun, Jin Wu, K. Moschner, K. Steiger, Naoki Fukuda, D. Kameda, Zs. Podolyák, P. A. Söderström, P. Doornenbal, F. Naqvi, K. Y. Chae, N. Kurz, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Physics, Nuclear and High Energy Physics, Isotope, Proton, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, lcsh:QC1-999, chemistry, Nucleosynthesis, Excited state, 0103 physical sciences, Neutron, Nuclide, Atomic physics, 010306 general physics, Nuclear Experiment, lcsh:Physics, Palladium
Abstract

The neutron-rich isotopes of palladium have attracted considerable interest in terms of the evolution of the N=82 neutron shell closure and its influence on the r-process nucleosynthesis. In this Letter, we present the first spectroscopic information on the excited states in Pd and Pd studied using the EURICA γ-ray spectrometer, following production via in-flight fission of a high-intensity U beam at the RIBF facility. New isomeric states with half-lives of 144(4) ns and 39(6) μs have been assigned spins and parities of (23/2 ) and (19/2 ) in Pd and Pd, respectively. The observed level properties are compared to a shell-model calculation, suggesting the competition between proton excitations and neutron excitations in the proton-hole and neutron-hole systems in the vicinity of the doubly magic nucleus Sn.

Published
2019

12. Decay spectroscopy of 160 Sm: The lightest four-quasiparticle K isomer

Author

Hiroyoshi Sakurai, P. H. Regan, István Kuti, M. Tanaka, Shunji Nishimura, H. Suzuki, Naohiro Inabe, Hiroki Nishibata, Tetsuro Komatsubara, T. Isobe, Toshiyuki Kubo, Rin Yokoyama, Shin'ichiro Michimasa, K. Kobayashi, Toshiyuki Sumikama, Zs. Dombrádi, N. Kurz, D. Kameda, E. Sahin, Ayumi Yagi, Zhengyu Xu, Atsuko Odahara, I. Kojouharov, R. Daido, Z. H. Li, Eiji Ideguchi, F. Browne, Stephen Rice, G. Benzoni, Zs. Podolyák, Jan Taprogge, Hiroyuki Takeda, H. Schaffner, P. Doornenbal, Guillaume Gey, H. L. Liu, Michikazu Kobayashi, Chang-Bum Moon, Hirofumi Watanabe, A. Gottardo, Nori Aoi, Zs. Vajta, Gary Simpson, F. L. Bello Garrote, I. Nishizuka, Shintaro Go, Zena Patel, P. M. Walker, N. Fukuda, L. Sinclair, P. A. Söderström, H. Baba, Y. F. Fang, Furong Xu, Masafumi Matsushita, Jin Wu, G. Lorusso, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Fizikai tudományok, State (functional analysis), 7. Clean energy, 01 natural sciences, lcsh:QC1-999, Természettudományok, 0103 physical sciences, Potential energy surface, Quasiparticle, ddc:530, Atomic physics, 010306 general physics, Ground state, Electronic band structure, Spectroscopy, ComputingMilieux_MISCELLANEOUS, lcsh:Physics, Excitation
Abstract

The decay of a new four-quasiparticle isomeric state in 160Sm has been observed using γ-ray spectroscopy at the RIBF, RIKEN. The four-quasiparticle state is assigned a 2 π ⊗ 2 ν π 5 2 − [ 532 ] , π 5 2 + [ 413 ] , ν 5 2 − [ 523 ] , ν 7 2 + [ 633 ] configuration. The half-life of this ( 11 + ) state is measured to be 1.8(4) μs. The ( 11 + ) isomer decays into a rotational band structure, based on a ( 6 − ) ν 5 2 − [ 523 ] ⊗ ν 7 2 + [ 633 ] bandhead, consistent with the g K − g R values. This decays to a ( 5 − ) two-proton quasiparticle state, which in turn decays to the ground state band. Potential energy surface and blocked-BCS calculations were performed in the deformed midshell region around 160Sm. They reveal a significant influence from β 6 deformation and that 160Sm is the best candidate for the lightest four-quasiparticle K isomer to exist in this region. The relationship between reduced hindrance and isomer excitation energy for E1 transitions from multiquasiparticle states is considered with the new data from 160Sm. The E1 data are found to agree with the existing relationship for E2 transitions.

Published
2016

13. Lifetime measurements of the first 2+ states in 104,106Zr: Evolution of ground-state deformations

Author

Eiji Ideguchi, T. Kubo, Giuseppe Lorusso, Mana Tanaka, Z. H. Li, Hiroshi Suzuki, D. Kameda, Atsuko Odahara, Y. F. Fang, R. Lozeva, Jan Taprogge, Pieter Doornenbal, Gary Simpson, Hiroyoshi Sakurai, I. Nishizuka, S. Nishimura, O. Wieland, Jin Wu, Tadaaki Isobe, Stephen Rice, P. A. Söderström, Ayumi Yagi, H. Takeda, F. Browne, I. Kojouharov, S. Lalkovski, P. H. Regan, Guillaume Gey, Hiroki Nishibata, Hidetada Baba, Naoki Fukuda, Raymond J. Carroll, Oliver J. Roberts, R. Daido, Zena Patel, Zs. Podolyák, T. Sumikama, V. Werner, N. Kurz, Zhengyu Xu, Alison Bruce, H. Schaffner, F. Didierjean, L. Sinclair, Nobuyuki Chiga, Hirofumi Watanabe, and Naohito Inabe

Subjects
Physics, Nuclear and High Energy Physics, Radionuclide, Isotope, Fission, Prolate spheroid, Nuclide, Deformation (engineering), Atomic physics, Ground state, Ionizing radiation
Abstract

The first fast-timing measurements from nuclides produced via the in-flight fission mechanism are reported. The lifetimes of the first 2+states in 104,106Zr nuclei have been measured via β-delayed γ-ray timing of stopped radioactive isotope beams. An improved precision for the lifetime of the 2+1state in 104Zr was obtained, τ(2+1) =2.90+25−20ns, as well as a first measurement of the 2+1state in 106Zr, τ(2+1) =2.60+20−15ns, with corresponding reduced transition probabilities of B(E2; 2+1→0+g.s.) =0.39(2)e2b2and 0.31(1)e2b2, respectively. Comparisons of the extracted ground-state deformations, β2=0.39(1)(104Zr) and β2=0.36(1)(106Zr) with model calculations indicate a persistence of prolate deformation. The data show that 104Zr is the most deformed of the neutron-rich Zr isotopes measured so far.

Published
2015

14. Identification of a millisecond isomeric state inCd81129via the detection of internal conversion and Compton electrons

Author

Naohiro Inabe, G. D. Kim, N. Fukuda, E. Nacher, M. Niikura, T. Isobe, Pieter Doornenbal, Giuseppe Lorusso, F.G. Kondev, D. Mücher, K. Yoshinaga, Atsuko Odahara, Y.-K. Kim, R. Orlandi, Guillaume Gey, Hiroshi Watanabe, Z. H. Li, D. Kameda, A. Gargano, Jin Wu, K. Moschner, Toshiyuki Sumikama, H. Baba, Zhengyu Xu, H. Schaffner, Hiroyuki Takeda, Jan Taprogge, G. S. Simpson, Toshiyuki Kubo, Ayumi Yagi, A. Covello, S. Ilieva, N. Kurz, A. Wendt, F. Drouet, Hyo Soon Jung, K. Steiger, L. Coraggio, H. Grawe, A. Jungclaus, Roman Gernhäuser, Z Vajta, P. A. Söderström, T. Kröll, A. Gadea, Hiroki Nishibata, I. Kojouharov, S. Nishimura, Frank Browne, G. Benzoni, Younghun Kwon, J.-M. Daugas, Z. Patel, S. Bönig, H. Sakurai, G. J. Lane, Zs. Podolyák, A. Montaner-Pizá, H. Suzuki, F. Naqvi, and K. Y. Chae

Subjects
Physics, Nuclear and High Energy Physics, Millisecond, Fission, Nuclear Theory, Electron, Nuclear isomer, 7. Clean energy, Internal conversion, Excited state, Atomic physics, Nuclear Experiment, Spin (physics), Beam (structure)
Abstract

The decay of an isomeric state in the neutron-rich nucleus 129 Cd has been observed via the detection of internal conversion and Compton electrons providing first experimental information on excited states in this nucleus. The isomer was populated in the projectile fission of a 238 U beam at the Radioactive Isotope Beam Factory at RIKEN. From the measured yields of γ -rays and internal conversion electrons, a multipolarity of E 3 was tentatively assigned to the isomeric transition. A half-life of T 1 / 2 = 3.6 ( 2 ) ms was determined for the new state which was assigned a spin of ( 21 / 2 + ) , based on a comparison to shell model calculations performed using state-of-the-art realistic effective interactions.

Published
2014

15. Isomer-delayed γ -ray spectroscopy of A=159–164 midshell nuclei and the variation of K -forbidden E1 transition hindrance factors

Author

Tetsuro Komatsubara, Hiroyoshi Sakurai, Toshiyuki Kubo, Hiroki Nishibata, P-A Soderstrom, Z. H. Li, Michikazu Kobayashi, Y. F. Fang, Masafumi Matsushita, P. H. Regan, Atsuko Odahara, Eiji Ideguchi, Jan Taprogge, Shunji Nishimura, T. Isobe, Naoki Fukuda, L. Sinclair, H. Baba, Zhengyu Xu, Naohito Inabe, Stephen Rice, A. Gottardo, F. Browne, Hirofumi Watanabe, G. Benzoni, Shin'ichiro Michimasa, F. L. Bello Garrote, I. Nishizuka, Toshiyuki Sumikama, Nori Aoi, T. Berry, N. Kurz, Ayumi Yagi, K. Kobayashi, Zs. Vajta, Rin Yokoyama, Furong Xu, Guillaume Gey, Hiroyuki Takeda, Qiong Wu, R. Daido, Zsolt Podolyak, István Kuti, D. Kameda, E. Sahin, Philip M Walker, P. Doornenbal, Jin Wu, Shintaro Go, G. Lorusso, Zena Patel, Momoko Tanaka, C-B Moon, Gary Simpson, H. Schaffner, Zs. Dombrádi, Hiroshi Suzuki, and I. Kojouharov

Subjects
Physics, Crystallography, 010308 nuclear & particles physics, Fission, Excited state, Pairing, 0103 physical sciences, Limited evidence, Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences
Abstract

Excited states have been studied in \iso{159}{Sm}, \iso{161}{Sm}, \iso{162}{Sm} (Z~=~62), \iso{163}{Eu} (Z~=~63), and \iso{164}{Gd} (Z~=~64), populated by isomeric decay following 238U projectile fission at RIBF, RIKEN. The isomer half-lives range from 50 ns to 2.6 \mus. In comparison with other published data, revised interpretations are proposed for \iso{159}{Sm} and \iso{163}{Eu}. The first data for excited states in \iso{161}{Sm} are presented, where a 2.6 \mus isomer is assigned a three-quasiparticle, K^\pi = 17/2^- structure. The interpretation is supported by multi-quasiparticle Nilsson-BCS calculations, including the blocking of pairing correlations. A consistent set of reduced E1 hindrance factors is obtained. Limited evidence is also reported for isomeric decay in 163Sm, 164Eu and 165Eu.

Published
2017

16. Observation of a $\gamma$-decaying millisecond isomeric state in $^{128}$Cd$_{80}$

Author

I. Kojouharov, Jan Taprogge, S. Ilieva, K. Moschner, A. Gargano, Hyo Soon Jung, Zhengyu Xu, P. A. Söderström, L. Coraggio, F. Naqvi, Ayumi Yagi, G. Benzoni, S. Bönig, Shunji Nishimura, Toshiyuki Sumikama, K. Yoshinaga, Zs. Vajta, Zena Patel, A. Jungclaus, Hiroyoshi Sakurai, Z. H. Li, G. D. Kim, F. Drouet, H. Grawe, N. Kurz, Hiroyuki Takeda, Young-Ki Kim, J. M. Daugas, T. Kröll, Younghun Kwon, F. Browne, G. J. Lane, Giuseppe Lorusso, A. Montaner-Pizá, R. Orlandi, H. Baba, H. Schaffner, Hiroshi Suzuki, Megumi Niikura, Nunzio Itaco, T. Isobe, D. Kameda, D. Mücher, Atsuko Odahara, F. G. Kondev, Guillaume Gey, Naoki Fukuda, P. Doornenbal, Hiroshi Watanabe, Zs. Podolyák, Jin Wu, K. Steiger, Hiroki Nishibata, Anna Wendt, K. Y. Chae, Naohito Inabe, Y. Shimizu, Gary Simpson, Toshiyuki Kubo, A. Gadea, Roman Gernhäuser, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Hungarian Scientific Research Fund, European Commission, Department of Energy (US), Science and Technology Facilities Council (UK), Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, German Research Foundation, SCOAP, National Research Foundation of Korea, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), RIKEN Nishina Center for Accelerator-Based Science, Japan Society for the Promotion of Science, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Jungclaus, A., Grawe, H., Nishimura, S., Doornenbal, P., Lorusso, G., Simpson, G. S., Sã¶derstrã¶m, P. -. A., Sumikama, T., Taprogge, J., Xu, Z. Y., Baba, H., Browne, F., Fukuda, N., Gernhã¤user, R., Gey, G., Inabe, N., Isobe, T., Jung, H. S., Kameda, D., Kim, G. D., Kim, Y. -. K., Kojouharov, I., Kubo, T., Kurz, N., Kwon, Y. K., Li, Z., Sakurai, H., Schaffner, H., Shimizu, Y., Steiger, K., Suzuki, H., Takeda, H., Vajta, Z. S., Watanabe, H., Wu, J., Yagi, A., Yoshinaga, K., Benzoni, G., Bã¶nig, S., Chae, K. Y., Coraggio, L., Daugas, J. -. M., Drouet, F., Gadea, A., Gargano, A., Ilieva, S., Itaco, N., Kondev, F. G., Krã¶ll, T., Lane, G. J., Montaner-pizã¡, A., Moschner, K., Mã¼cher, D., Naqvi, F., Niikura, M., Nishibata, H., Odahara, A., Orlandi, R., Patel, Z., Podolyã¡k, Z. S., and Wendt, A.

Subjects
Shell model calculation, Nuclear and High Energy Physics, Fission, SHELL model, Nuclear Theory, Shell model calculations, Transition strengths, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, 0103 physical sciences, medicine, ddc:530, 010306 general physics, Nuclear Experiment, Physics, Millisecond, Radionuclide, Isomeric decay, 010308 nuclear & particles physics, Projectile, Parity (physics), lcsh:QC1-999, medicine.anatomical_structure, Isomeric decays, Physics::Accelerator Physics, Transition strength, Atomic physics, Nucleus, lcsh:Physics
Abstract

A. Jungclaus et al. -- 6 pags., 5 figs., 2 tabs. -- Open Access funded by Creative Commons Atribution Licence 4.0, A new high-spin isomer in the neutron-rich nucleus Cd was populated in the projectile fission of a U beam at the Radioactive Isotope Beam Factory at RIKEN. A half-life of T=6.3(8) ms was measured for the new state which was tentatively assigned a spin/parity of (15). The experimental results are compared to shell model calculations performed using state-of-the-art realistic effective interactions and to the neighbouring nucleus Cd. In the present experiment no evidence was found for the decay of a 18 E6 spin-trap isomer, based on the complete alignment of the two-neutron and two-proton holes in the 0h and the 0g orbit, respectively, which is predicted to exist by the shell model., We thank the staff of the RIKEN Nishina Center accelerator complex for providing stable beams with high intensities to the experiment. We acknowledge the EUROBALL Owners Committee for the loan of germanium detectors and the PreSpec Collaboration for the readout electronics of the cluster detectors. This work was supported by the Spanish Ministerio de Ciencia e Innovación under contract FPA2011-29854-C04 and the Spanish Ministerio de Economía y Competitividad under contract FPA2014-57196-C5-4-P, the Generalitat Valenciana (Spain) under grant PROMETEO/2010/101, the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (NRF-2014S1A2A2028636, 2016K1A3A7A09005579, 2016R1A5A1013277), the Priority Centers Research Program in Korea (2009-0093817), OTKA contract number K-100835, JSPS KAKENHI (Grant No. 25247045), the European Commission through the Marie Curie Actions call FP7-PEOPLE-2011-IEF under Contract No. 300096, the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357, the STFC (UK), the “RIKEN foreign research program”, the German BMBF (No. 05P12RDCIA, 05P12RDNUP and 05P12PKFNE), HIC for FAIR, the DFG cluster of excellence “Origin and Structure of the Universe” and DFG (Contract No. KR2326/2-1).

Published
2017

17. Observation of new neutron-rich Mn, Fe, Co, Ni, and Cu isotopes in the vicinity of $^{78}$Ni

Author

Naohito Inabe, Shin-Ichiro Nishimura, Takashi Kubo, Atsuko Odahara, H. S. Jung, Jan Taprogge, P. Morfouace, I. Matea, Ryo Taniuchi, H. Takeda, Hiroki Nishibata, P. A. Söderström, G. I. Stefan, K. Matsui, Toshiyuki Sumikama, Hiroyoshi Sakurai, D. Mengoni, K. Yoshinaga, Zhengyu Xu, Naoki Fukuda, Hiroshi Suzuki, Z. H. Li, Zs. Vajta, F. Browne, Guillaume Gey, Megumi Niikura, S. Franchoo, T. Isobe, V. Werner, P. R. John, Ayumi Yagi, Giuseppe Lorusso, D. R. Napoli, H. Baba, D. Kameda, E. Sahin, P. Doornenbal, Daisuke Suzuki, Jin Wu, Hirofumi Watanabe, 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 Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Japan Society for the Promotion of Science, Ministerio de Ciencia e Innovación (España), Hungarian Scientific Research Fund, National Research Foundation of Korea, 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 Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Physics, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, Fission, Qualitative evidence, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Weak binding, 0103 physical sciences, Neutron, Production (computer science), Atomic physics, 010306 general physics, Nuclear Experiment, Beam (structure), Energy (signal processing)
Abstract

5 pags., 3 figs., 2 tabs., Neutron-rich nuclei in the vicinity of Ni78 were produced using a U238 beam at the RIKEN Radioactive Isotope Beam Factory. The particle-identification plot for the in-flight fission fragments highlights the first observation of eight new isotopes: Mn73, Fe76, Co77,78, Ni80,81,82, and Cu83. Although the β-decay half-lives of Co77 and Ni80 were recently reported by Xu [Phys. Rev. Lett. 113, 032505 (2014)]PRLTAO0031-900710.1103/PhysRevLett.113.032505 using data from the same experiment, the current work provides the first direct, quantitative evidence for the existence of these isotopes. The experimental production cross sections are reproduced in a satisfactory manner by theoretical predictions. An odd-even staggering of the cross sections was observed, and the effect appears to become more pronounced for the most exotic nuclei that were investigated. The staggering effect was interpreted as an increase of the neutron-evaporation probability for odd-N isotopes, owing to the decrease of the neutron-separation energy, Sn. The predicted cross section for Ni80 is significantly overestimated, which may be related to a weak binding of the neutron pair above the N=50 shell closure., This work was supported by JSPS KAKENHI (25247045, 25800130), the Spanish Ministerio de Ciencia e Innovación under Contracts No. FPA2009-13377-C02 and No. FPA2011- 29854-C04, OTKA Contract No. K-100835, U.S. DOE Contract No. DE-FG02-91ER40609, and the Priority Centers Research Program in Korea (2009-0093817).

Published
2017

18. μs isomers of Nd158,160

Author

F. L. Bello Garrote, I. Nishizuka, F. Browne, Toshiyuki Sumikama, Shunji Nishimura, István Kuti, Y. F. Fang, Hiroyuki Takeda, Jinguang Wu, N. Kurz, Hiroyoshi Sakurai, G. Benzoni, H. Schaffner, Tetsuro Komatsubara, Stephen Rice, Toshiyuki Kubo, Naohito Inabe, Chang-Bum Moon, Giuseppe Lorusso, Jan Taprogge, Atsuko Odahara, Guillaume Gey, T. Isobe, Rin Yokoyama, K. Kobayashi, Naoki Fukuda, Hiroshi Suzuki, D. Kameda, I. Kojouharov, Shin'ichiro Michimasa, Hiroshi Watanabe, P. A. Söderström, E. Sahin, Ayumi Yagi, M. Tanaka, Eiji Ideguchi, Z. H. Li, Masafumi Matsushita, R. Daido, Motoki Kobayashi, Nori Aoi, Z. Patel, L. Sinclair, Hiroki Nishibata, P. Doornenbal, H. Baba, Zs. Vajta, Shintaro Go, A. Gottardo, Zhengyu Xu, and Gary Simpson

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

The neutron-rich nuclei $^{158,160}\mathrm{Nd}$ have been studied via delayed $\ensuremath{\gamma}$-ray spectroscopy of $\ensuremath{\mu}\mathrm{s}$ isomeric states at the RIBF facility, RIKEN. These nuclei were produced following the projectile fission of a 345 $A\phantom{\rule{0.16em}{0ex}}\mathrm{MeV}\phantom{\rule{4pt}{0ex}}^{238}\mathrm{U}$ beam and delayed $\ensuremath{\gamma}$ rays were detected by the EURICA cluster Ge array. The isomeric states have measured half-lives of 339(20) ns and 1.63(21) $\ensuremath{\mu}\mathrm{s}$ for $^{158}\mathrm{Nd}$ and $^{160}\mathrm{Nd}$, respectively. From the observed $\ensuremath{\gamma}$ decays and the systematics of levels in the neighboring Nd isotopes first level schemes were constructed for these nuclei. The isomeric states of $^{158,160}\mathrm{Nd}$ have been assigned spins of $({6}^{\ensuremath{-}})$ and $({4}^{\ensuremath{-}})$, with proposed $\ensuremath{\nu}5/2[523]\ensuremath{\bigotimes}\ensuremath{\nu}7/2[633]$ and $\ensuremath{\nu}1/2[521]\ensuremath{\bigotimes}\ensuremath{\nu}7/2[633]$ configurations, respectively.

Published
2016

19. Erratum to: Proton-hole and core-excited states in the semi-magic nucleus 131In82

Author

Hiroki Nishibata, Zhengyu Xu, Nunzio Itaco, Naoki Fukuda, Zs. Podolyák, K. Y. Chae, F. Naqvi, K. Moschner, Shunji Nishimura, T. Isobe, Hiroshi Watanabe, H. Grawe, K. Yoshinaga, G. D. Kim, Roman Gernhäuser, K. Steiger, Young-Ki Kim, A. Gargano, Naohito Inabe, Zena Patel, Younghun Kwon, A. Montaner-Pizá, D. Kameda, Jin Wu, Z. H. Li, S. Ilieva, P. Doornenbal, R. Orlandi, Ayumi Yagi, T. Kröll, H. Schaffner, S. Bönig, A. Jungclaus, N. Kurz, Jan Taprogge, Toshiyuki Kubo, F. G. Kondev, Y. Shimizu, J. M. Daugas, A. Gadea, I. Kojouharov, Hiroshi Suzuki, Ivan Borzov, Hyo Soon Jung, F. Browne, Guillaume Gey, L. Coraggio, Atsuko Odahara, Hiroyoshi Sakurai, Gary Simpson, P. A. Söderström, Megumi Niikura, Zs. Vajta, F. Drouet, D. Mücher, H. Baba, Anna Wendt, G. Benzoni, Toshiyuki Sumikama, Hiroyuki Takeda, G. J. Lane, and Giuseppe Lorusso

Subjects
Core (optical fiber), Physics, Nuclear and High Energy Physics, medicine.anatomical_structure, Proton, Excited state, Hadron, medicine, Nuclear fusion, MAGIC (telescope), Atomic physics, Nucleus
Published
2016

20. βdecay of semi-magicCd130: Revision and extension of the level scheme ofIn130

Author

F. G. Kondev, F. Browne, Hiroyoshi Sakurai, G. D. Kim, Guillaume Gey, Anna Wendt, Zhengyu Xu, Z. H. Li, H. Baba, Shunji Nishimura, A. Gargano, S. Ilieva, J. M. Daugas, Toshiyuki Sumikama, A. Jungclaus, Hiroyuki Takeda, F. Naqvi, Hiroshi Suzuki, I. Kojouharov, Toshiyuki Kubo, R. Orlandi, Roman Gernhäuser, G. J. Lane, H. Grawe, Giuseppe Lorusso, Zsolt Podolyak, Z Vajta, L. Coraggio, N. Kurz, K. Steiger, Ayumi Yagi, S. Bönig, Hiroki Nishibata, Jin Wu, K. Moschner, Young-Ki Kim, D. Kameda, H. S. Jung, P. Doornenbal, Nunzio Itaco, Naoki Fukuda, Jan Taprogge, Zena Patel, G. Benzoni, K. Yoshinaga, Megumi Niikura, D. Mücher, K. Y. Chae, F. Drouet, A. Gadea, Gary Simpson, P. A. Söderström, Younghun Kwon, A. Montaner-Pizá, Atsuko Odahara, Naohito Inabe, Y. Shimizu, H. Schaffner, T. Isobe, Hiroshi Watanabe, and T. Kröll

Subjects
Physics, Nuclear physics, 010308 nuclear & particles physics, 0103 physical sciences, Library science, European commission, 010306 general physics, 7. Clean energy, 01 natural sciences, Marie curie
Abstract

This work was supported by the Spanish Ministerio de Ciencia e Innovacion under contract FPA2011-29854-C04 and the Spanish Ministerio de Economia y Competitividad under Contract No. FPA2014-57196-C5- 4-P, the Generalitat Valenciana (Spain) under Grant No. PROMETEO/2010/101, the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (NRF-2014S1A2A2028636, 2016K1A3A7A09005579), the Priority Centers Research Program in Korea (2009-0093817), OTKA Contract No. K-100835, JSPS KAKENHI (Grant No. 25247045), the European Commission through the Marie Curie Actions call FP7-PEOPLE-2011-IEF under Contract No. 300096, the US Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357, the STFC (UK), the “RIKEN foreign research program,” the German BMBF (No. 05P12RDCIA, No. 05P12RDNUP, and No. 05P12PKFNE), HIC for FAIR, the DFG cluster of excellence “Origin and Structure of the Universe,” and DFG (Contract No. KR2326/2-1)

Published
2016

21. First observation ofγrays emitted from excited states south-east ofSn132: Theπg9/2−1⊗νf7/2multiplet ofIn83132

Author

H. Baba, Ayumi Yagi, S. Bönig, Young-Ki Kim, Toshiyuki Sumikama, Younghun Kwon, A. Montaner-Pizá, Shunji Nishimura, Hiroyuki Takeda, H. S. Jung, Z. H. Li, A. Jungclaus, Giuseppe Lorusso, Jan Taprogge, Roman Gernhäuser, D. Mücher, Hiroki Nishibata, A. Gargano, D. Kameda, Z Vajta, Hiroshi Suzuki, A. Gadea, F. Drouet, G. D. Kim, Hiroyoshi Sakurai, Anna Wendt, Gary Simpson, J. M. Daugas, T. Isobe, K. Yoshinaga, Jin Wu, P. Doornenbal, Hiroshi Watanabe, K. Moschner, R. Orlandi, S. Ilieva, I. Kojouharov, Zhengyu Xu, F. Browne, L. Coraggio, Guillaume Gey, K. Steiger, Nunzio Itaco, Toshiyuki Kubo, Naoki Fukuda, Y. Shimizu, H. Grawe, N. Kurz, Naohito Inabe, P. A. Söderström, H. Schaffner, Atsuko Odahara, and T. Kröll

Subjects
Physics, Radionuclide, 010308 nuclear & particles physics, Fission, Projectile, Neutron emission, 01 natural sciences, Nuclear physics, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Multiplet, Scaling
Abstract

For the first time, the γ decay of excited states has been observed in a nucleus situated in the quadrant south-east of doubly magic Sn132, a region in which experimental information so far is limited to ground-state properties. Six γ rays with energies of 50, 86, 103, 227, 357, and 602 keV were observed following the β-delayed neutron emission from Cd85133, populated in the projectile fission of a U238 beam at the Radioactive Isotope Beam Factory at RIKEN within the EURICA project. The new experimental information is compared to the results of a modern realistic shell-model calculation, the first one in this region very far from stability, focusing in particular on the π0g9/2-1 - ν1f7/2 particle-hole multiplet in In83132. In addition, theoretical estimates based on a scaling of the two-body matrix elements for the πh11/2-1 - νg9/2 analog multiplet in Tl127208, one major proton and one major neutron shell above, are presented. © 2016 American Physical Society.

Published
2016

22. Spectroscopy of Pionic Atoms Via (p, 2He) Reaction

Author

Watanabe, Yuni N., primary, Adachi, Satoshi, additional, Aoi, Nori, additional, Ashikaga, Sakiko, additional, Fujioka, Hiroyuki, additional, Furuno, Tatsuya, additional, Geissel, Hans, additional, Guillaume, Gey, additional, Hashimoto, Takashi, additional, Hatanaka, Kichiji, additional, Hayano, Ryugo S., additional, Heguri, Katsuyoshi, additional, Inaba, Kento, additional, Inoue, Azusa, additional, Itahashi, Kenta, additional, Iwamoto, Chihiro, additional, Kawabata, Takahiro, additional, Matsuda, Yohei, additional, Matsumoto, Shota, additional, Morimoto, Takahiro, additional, Murata, Motoki, additional, Nishi, Takahiro, additional, Noji, Shunpei, additional, Ong, Hooi J., additional, Sakaue, Akane, additional, Takahashi, Yu, additional, Tamii, Atsushi, additional, Tanaka, Yoshiki K., additional, Tang, Tsz L., additional, Terashima, Satoru, additional, Tsumura, Miho, additional, and Watanabe, Ken, additional

Published
2017
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23. Study of Intermediate-spin States of $^{98}$Y

Author

Steffen Ketelhut, Juha Sorri, G. S. Simpson, G. Thiamova, Petr Alexa, Grégoire Kessedjian, Rauno Julin, Tuomas Grahn, C. Sage, Paul Greenlees, Juha Uusitalo, Sami Rinta-Antila, K. Hauschild, M. Ramdhane, Pauli Peura, A. Lopez-Martens, Jan Sarén, Catherine Scholey, Ulrika Jakobsson, T. Malkiewicz, Andrej Herzan, Peter B. Jones, Guillaume Gey, Paivi Nieminen, Panu Rahkila, Panu Ruotsalainen, Mikael Sandzelius, A. Vancraeyenest, F. Drouet, Sakari Juutinen, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Physics, gamma decay, ta114, Spin states, Spins, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Fission, Isotone, Nuclear Theory, Nuclear structure, General Physics and Astronomy, Prolate spheroid, spin states, 7. Clean energy, Nuclear physics, yttrium, medicine.anatomical_structure, nuclear structure, medicine, Atomic physics, Nuclear Experiment, Nucleus
Abstract

The nuclear structure of the odd–odd nucleus 98Y has been re-investigated by observing prompt γ rays emitted following the proton-induced fission of a 238U target, using the JUROGAM-II multidetector array. New highspin decays have been observed and placed in the level schemes using triple coincidences. The experimental level energies and γ-decay patterns are compared to GICM and QPRM calculations, assuming that this neutronrich N = 59 isotone is spherical at low energies and prolate deformed at intermediate spins. Web of Science 47 3 916 911

Published
2015

24. Isomers of Pm Isotopes on the Neutron-Rich Frontier of the Deformed Z ~ 60 Region

Author

Y. F. Fang, N. Fukuda, Daisuke Kameda, Mana Tanaka, Simon Rice, Gary Simpson, F. Browne, Giuseppe Lorusso, Laura C. Sinclair, Rin Yokoyama, Guillaume Gey, Masafumi Matsushita, Jan Taprogge, Shunji Nishimura, Kazuma Kobayashi, Naohiro Inabe, István Kuti, Hiroki Nishibata, Toshiyuki Sumikama, Tetsuro Komatsubara, Toshiyuki Kubo, Hiroyuki Takeda, Zhihuan Li, Zs. Vajta, Atsuko Odahara, Zhengyu Xu, Frank Bello, Pär-Anders Söderström, Motoki Kobayashi, Nori Aoi, Tadaaki Isobe, Chang-Bum Moon, Shin'ichiro Michimasa, Ayumi Yagi, I. Nishizuka, R. Daido, Jin Wu, Hidetada Baba, Shintaro Go, Hiroshi Watanabe, Eiji Ideguchi, Zena Patel, E. Sahin, H. Suzuki, and Pieter Doornnbal

Subjects
Nuclear physics, Physics, Frontier, Isotope, Neutron
Published
2015

25. βdecay ofCd129and excited states inIn129

Author

Z. H. Li, Shunji Nishimura, F. Browne, T. Kröll, F. G. Kondev, Guillaume Gey, P. A. Söderström, T. Isobe, Jan Taprogge, Anna Wendt, Hiroshi Watanabe, K. Moschner, Jinguang Wu, Zhengyu Xu, H. Baba, G. J. Lane, Giuseppe Lorusso, D. Kameda, K. Yoshinaga, Ayumi Yagi, S. Bönig, F. Drouet, Naoki Fukuda, G. D. Kim, A. Gargano, P. Doornenbal, Zs. Podolyák, S. Ilieva, J. M. Daugas, Toshiyuki Sumikama, Hiroki Nishibata, R. Orlandi, A. Covello, Hiroyuki Takeda, H. Grawe, N. Kurz, H. Schaffner, G. Benzoni, Hyo Soon Jung, D. Mücher, K. Y. Chae, Megumi Niikura, Atsuko Odahara, Hiroyoshi Sakurai, Z. Patel, Zs. Vajta, K. Steiger, F. Naqvi, Toshiyuki Kubo, Gary Simpson, A. Gadea, I. Kojouharov, L. Coraggio, Roman Gernhäuser, Naohito Inabe, A. Jungclaus, Hiroshi Suzuki, Young-Ki Kim, Younghun Kwon, and A. Montaner-Pizá

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, 01 natural sciences
Published
2015

26. β-Decay Half-Lives of 110 Neutron-Rich Nuclei across theN=82Shell Gap: Implications for the Mechanism and Universality of the AstrophysicalrProcess

Author

H. Baba, Toshiyuki Kubo, Megumi Niikura, Zena Patel, Shunji Nishimura, Hiroki Nishibata, Atsuko Odahara, Hiroyoshi Sakurai, D. Kameda, Tadaaki Isobe, P. Schury, Naohiro Inabe, A. Jungclaus, Hyo Soon Jung, Anna Wendt, Pieter Doornenbal, G. D. Kim, Young-Ki Kim, Hiroshi Suzuki, Toshiyuki Sumikama, F. C. L. Crespi, Bradley S. Meyer, Roman Gernhäuser, Hiroyuki Takeda, K. Steiger, Younghun Kwon, A. Montaner-Pizá, Giuseppe Lorusso, F. G. Kondev, F. Browne, R. Orlandi, Y. Shimizu, P. A. Söderström, Zs. Vajta, Guillaume Gey, Ayumi Yagi, Jan Taprogge, Hiroshi Watanabe, Z. H. Li, Jin Wu, F. Naqvi, I. Kojouharov, G. Benzoni, K. Moschner, S. Shibagaki, Zhengyu Xu, Toshitaka Kajino, Gary Simpson, H. Schaffner, K. Yoshinaga, Gregory Lane, K. Y. Chae, Naoki Fukuda, Zs. Podolyák, and N. Kurz

Subjects
Nuclear physics, Physics, Stars, Isotope, Double beta decay, General Physics and Astronomy, r-process, Neutron, 7. Clean energy, Universality (dynamical systems)
Abstract

The $\ensuremath{\beta}$-decay half-lives of 110 neutron-rich isotopes of the elements from $_{37}\mathrm{Rb}$ to $_{50}\mathrm{Sn}$ were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for $r$-process calculations and reinforce the notion that the second ($A\ensuremath{\approx}130$) and the rare-earth-element ($A\ensuremath{\approx}160$) abundance peaks may result from the freeze-out of an $(n,\ensuremath{\gamma})\ensuremath{\rightleftarrows}(\ensuremath{\gamma},n)$ equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the $r$ process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual $r$-process events.

Published
2015

27. Isomer Decay Spectroscopy ofSm164andGd166: Midshell Collectivity AroundN=100

Author

Naoki Fukuda, Zs. Podolyák, Tetsuro Komatsubara, Toshiyuki Kubo, G. Benzoni, Toshiyuki Sumikama, H. Schaffner, Masao Kobayashi, Pieter Doornenbal, István Kuti, Hiroki Nishibata, Q. D. Wu, Hiroyuki Takeda, Jin Wu, Zhengyu Xu, Shunji Nishimura, Mana Tanaka, Hiroyoshi Sakurai, Giuseppe Lorusso, A. Gottardo, Nori Aoi, Naohiro Inabe, Eiji Ideguchi, K. Kobayashi, Shin'ichiro Michimasa, Simon Rice, Ayumi Yagi, H. L. Liu, P. H. Regan, Z. H. Li, Jan Taprogge, N. Kurz, Pär-Anders Söderström, L. Sinclair, F. L. Bello Garrote, I. Nishizuka, Y. F. Fang, Gary Simpson, D. Kameda, F. Browne, E. Sahin, I. Kojouharov, Hiroshi Watanabe, Guillaume Gey, H. Baba, Tadaaki Isobe, Chang-Bum Moon, Furong Xu, Hiroshi Suzuki, Zs. Vajta, Rin Yokoyama, Atsuko Odahara, R. Daido, Shintaro Go, Zena Patel, Philip M Walker, and Masafumi Matsushita

Subjects
Physics, Nuclear physics, Excited state, Potential energy surface, General Physics and Astronomy, Parity (physics), Observable, Atomic physics, Spectroscopy, Nuclear shape, Ionizing radiation
Abstract

Excited states in the N=102 isotones 166Gd and 164Sm have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for 166Gd and 164Sm, respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of 166Gd and 164Sm (N=102) compared to 164Gd and 162Sm (N=100), respectively, presents evidence for the predicted deformed shell closure at N=100.

Published
2014

28. Yrast 6+Seniority Isomers of136,138Sn

Author

Hiroyoshi Sakurai, Shunji Nishimura, D. Mücher, Atsuko Odahara, Naohiro Inabe, Toshiyuki Sumikama, Zs. Vajta, J. M. Daugas, H. Naïdja, Hiroyuki Takeda, T. Kröll, I. Kojouharov, G. D. Kim, Giuseppe Lorusso, K. Steiger, F. Drouet, Pieter Doornenbal, Zhengyu Xu, Young-Ki Kim, R. Orlandi, Y. Shimizu, Younghun Kwon, Ayumi Yagi, Toshiyuki Kubo, A. Montaner-Pizá, Anna Wendt, K. Yoshinaga, Jin Wu, F. Browne, G. S. Simpson, Jan Taprogge, D. Kameda, H. Baba, K. Moschner, Tadaaki Isobe, Hiroki Nishibata, S. Ilieva, Guillaume Gey, H. Schaffner, Z. H. Li, A. Jungclaus, N. Kurz, Pär-Anders Söderström, Hyo Soon Jung, Naoki Fukuda, Hiroshi Suzuki, Roman Gernhäuser, S. Bönig, Hiroshi Watanabe, F. Nowacki, and Kamila Sieja

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, Yrast, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Nuclear physics, Matrix (mathematics), Seniority (financial), Excited state, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Beam (structure)
Abstract

Delayed γ-ray cascades, originating from the decay of (6⁺) isomeric states, in the very neutron-rich, semimagic isotopes (136,138)Sn have been observed following the projectile fission of a ²³⁸U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2;6⁺→4⁺) rate of ¹³⁶Sn, which deviates from a simple seniority scheme. Empirically reducing the νf(7/2)(2) orbit matrix elements produces a 4₁⁺ state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2;6⁺→4⁺) rate of ¹³⁶Sn. These data provide a key benchmark for shell-model interactions far from stability.

Published
2014

29. Erratum:1p3/2Proton-Hole State inSn132and the Shell Structure AlongN=82[Phys. Rev. Lett. 112, 132501 (2014)]

Author

H. Baba, Zhengyu Xu, Young-Ki Kim, J. M. Daugas, A. Jungclaus, G. J. Lane, Giuseppe Lorusso, Z. H. Li, D. Kameda, H. Schaffner, Younghun Kwon, A. Montaner-Pizá, T. Kröll, K. Y. Chae, Shunji Nishimura, Atsuko Odahara, Hiroyoshi Sakurai, Jinguang Wu, F. G. Kondev, Hiroshi Suzuki, I. Kojouharov, P. Doornenbal, Toshiyuki Kubo, T. Isobe, H. Grawe, N. Kurz, Ayumi Yagi, Naohito Inabe, S. Bönig, Hiroshi Watanabe, F. Drouet, F. Naqvi, G. D. Kim, Naoki Fukuda, Zs. Podolyák, Megumi Niikura, Hiroki Nishibata, K. Steiger, L. Coraggio, K. Moschner, G. Benzoni, Toshiyuki Sumikama, Hiroyuki Takeda, F. Browne, A. Gadea, Guillaume Gey, P. A. Söderström, Anna Wendt, S. Ilieva, Jan Taprogge, Roman Gernhäuser, Hyo Soon Jung, D. Mücher, R. Orlandi, A. Covello, Gary Simpson, K. Yoshinaga, Z. Patel, A. Gargano, and Zs. Vajta

Subjects
Physics, Proton, Double beta decay, SHELL model, General Physics and Astronomy, State (functional analysis), Atomic physics, Beta decay
Published
2014

30. β -Decay Half-Lives of Co76,77 , Ni79,80 , and Cu81 : Experimental Indication of a Doubly Magic Ni78

Author

F. Browne, Guillaume Gey, I. Stefan, K. Matsui, Shunji Nishimura, Pär-Anders Söderström, H. S. Jung, Zhengyu Xu, E. Sahin, Jan Taprogge, Z. H. Li, H. Baba, H. Schaffner, Ryo Taniuchi, N. Kurz, Atsuko Odahara, Shigeru Kubono, Daisuke Suzuki, Pieter Doornenbal, P. Morfouace, Hiroyoshi Sakurai, Hiroshi Watanabe, I. Matea, K. Yoshinaga, Megumi Niikura, D. Mengoni, P. R. John, Hiroki Nishibata, Zs. Vajta, F. Naqvi, Ayumi Yagi, Jin Wu, I. Kojouharov, V. Werner, Tadaaki Isobe, Toshiyuki Sumikama, D. R. Napoli, Giuseppe Lorusso, and S. Franchoo

Subjects
Physics, Crystallography, 010308 nuclear & particles physics, Double beta decay, Neutron number, 0103 physical sciences, General Physics and Astronomy, Atomic number, MAGIC (telescope), 010306 general physics, 01 natural sciences
Abstract

The half-lives of 20 neutron-rich nuclei with $Z=27--30$ have been measured at the RIBF, including five new half-lives of $^{76}\mathrm{Co}(21.{7}_{\ensuremath{-}4.9}^{+6.5}\text{ }\text{ }\mathrm{ms})$, $^{77}\mathrm{Co}(13.{0}_{\ensuremath{-}4.3}^{+7.2}\text{ }\text{ }\mathrm{ms})$, $^{79}\mathrm{Ni}({43.0}_{\ensuremath{-}7.5}^{+8.6}\text{ }\text{ }\mathrm{ms})$, $^{80}\mathrm{Ni}(23.{9}_{\ensuremath{-}17.2}^{+26.0}\text{ }\text{ }\mathrm{ms})$, and $^{81}\mathrm{Cu}(73.2\ifmmode\pm\else\textpm\fi{}6.8\text{ }\text{ }\mathrm{ms})$. In addition, the half-lives of $^{73--75}\mathrm{Co}$, $^{74--78}\mathrm{Ni}$, $^{78--80}\mathrm{Cu}$, and $^{80--82}\mathrm{Zn}$ were determined with higher precision than previous works. Based on these new results, a systematic study of the $\ensuremath{\beta}$-decay half-lives has been carried out, which suggests a sizable magicity for both the proton number $Z=28$ and the neutron number $N=50$ in $^{78}\mathrm{Ni}$.

Published
2014

31. 1p3/2Proton-Hole State inSn132and the Shell Structure AlongN=82

Author

T. Kröll, I. Kojouharov, Shunji Nishimura, Zs. Vajta, F. G. Kondev, Naohiro Inabe, F. Drouet, Jan Taprogge, H. Schaffner, Roman Gernhäuser, Pär-Anders Söderström, D. Mücher, Atsuko Odahara, A. Gadea, H. Baba, Toshiyuki Sumikama, L. Coraggio, Megumi Niikura, Pieter Doornenbal, Tadaaki Isobe, Ayumi Yagi, K. Y. Chae, Gary Simpson, F. Naqvi, Z. H. Li, A. Jungclaus, S. Bönig, Hiroyoshi Sakurai, Toshiyuki Kubo, A. Covello, G. D. Kim, Hiroyuki Takeda, Hiroshi Watanabe, Hiroshi Suzuki, Hiroki Nishibata, J. M. Daugas, Young-Ki Kim, K. Yoshinaga, K. Moschner, G. J. Lane, Giuseppe Lorusso, Younghun Kwon, D. Kameda, A. Montaner-Pizá, H. Grawe, Zena Patel, Hyo Soon Jung, N. Kurz, Jin Wu, A. Gargano, Zhengyu Xu, F. Browne, G. Benzoni, K. Steiger, Zs. Podolyák, Guillaume Gey, Anna Wendt, N. Fukuda, S. Ilieva, and R. Orlandi

Subjects
Physics, Nuclear physics, Proton, Double beta decay, SHELL model, General Physics and Astronomy, State (functional analysis), Engineering physics, Beta decay
Abstract

5 pags. ; 3 figs. ; PACS numbers: 23.40.-s, 21.10.Pc, 27.60.+j, 21.60.Cs ; Taprogge, J., et al.

Published
2014

32. Status of the EURICA Project After One Year at RIKEN

Author

Plamen Boutachkov, Eiji Ideguchi, T. Isobe, Oliver Roberts, Pär-Anders Söderström, Rin Yokoyama, L. Sinclair, Roman Gernhäuser, Z Vajta, Y. F. Fang, Shunji Nishimura, Hidetada Baba, Chang-Bum Moon, Zhengyu Xu, Gi Dong Kim, A. Jungclaus, Atsuko Odahara, Yong-Kyun Kim, Young Kwan Kwon, Kevin Mochner, R. Wadsworth, Daniel Lubos, Jin Wu, Ivan Kojouharov, Jan Taprogge, Giovanna Benzoni, Ayumi Yagi, Zhong Liu, Kenta Yoshinaga, Guillaume Gey, Pieter Doornenbal, Radomira Lozeva, M. Lewitowicz, Frank Browne, Henning Schaffner, Hiroyoshi Sakurai, Nikolaus Kurz, R. Daido, Andrey Blazhev, Megumi Niikura, Gary Simpson, Christopher Townsley, Simon Rice, Alison Bruce, P. H. Regan, Z. Patel, Hyo-Soon Jung, Toshiyuki Sumikama, Giuseppe Lorusso, Zsolt Podolyak, Hiroshi Watanabe, and Zhihuan Li

Subjects
Physics
Published
2014

33. Systematic Study of β-Decay Half-Lives in the Vicinity of 78Ni

Author

Jan Taprogge, Pieter Doornenbal, Giuseppe Lorusso, Zhihuan Li, Frank Brown, Hyo-Soon Jung, K. Yoshinaga, Hiroki Nishibata, Guillaume Gey, Megumi Niikura, P. R. John, Ayumi Yagi, Shunji Nishimura, Hidetada Baba, Hiroshi Watanabe, Toshiyuki Sumikama, Hiroyoshi Sakurai, Zs. Vajta, Daniele Mengoni, K. Matsui, E. Sahin, D. R. Napoli, Iulian G. Stefan, Zhengyu Xu, Tadaaki Isobe, Pär-Anders Söderström, Atsuko Odahara, and Jin Wu

Subjects
Physics, Nuclear physics, Fission, Spectroscopy
Abstract

An experiment aiming at study of decay spectroscopy around ^78Ni has been performed at the RIBF facility, RIKEN, in the winter of 2012. The β-decay half-lives of ^72–73Co, ^75–76Ni, ^78Cu, ^80–81Zn, and ^83Ga, which were produced by the in-flight fission of ^238U on a ^9Be target, were deduced with good agreements with literature values of available.

Published
2014

34. Prompt gamma ray-spectroscopy of N = 50 fission fragments

Author

M. Ramdhane, Jan Sarén, Steffen Ketelhut, Panu Ruotsalainen, Andrej Herzan, F. Drouet, K. Hauschild, Rauno Julin, C. Scholey, Paul Greenlees, S. Juutinen, Gary Simpson, T. Malkiewicz, Guillaume Gey, Pauli Peura, A. Vancraeyenest, Tuomas Grahn, Grégoire Kessedjian, Juha Uusitalo, Panu Rahkila, Paivi Nieminen, Peter M. Jones, Mikael Sandzelius, G. Thiamova, C. Sage, A. Lopez-Martens, Juha Sorri, Ulrika Jakobsson, Sami Rinta-Antila, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, ta114, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Nuclear Theory, 01 natural sciences, 7. Clean energy, Coincidence, Nuclear physics, Excited state, 0103 physical sciences, Gamma spectroscopy, Atomic physics, 010306 general physics, Spectroscopy, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS
Abstract

Excited states in the nuclei 83 As and 84,86 Se have been studied via prompt -ray spectroscopy. The nuclei were produced by the proton-induced fission of a 238 U target, at the accelerator of the University of Jyvaskyla. The JUROGAM-II array was used to detect prompt -rays and a triple- coincidence analysis performed. A comparison of the N = 50 nuclei with shell-model calculations reproduces the low-lying states in 83 As and 84 Se well. The inclusion of particle-hole excitations is necessary to correctly describe the states above ∼ 3.5 MeV.

Published
2013

35. Isomers inPd128andPd126: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes

Author

F. Browne, Shunji Nishimura, Guillaume Gey, Atsuko Odahara, Pieter Doornenbal, Naohiro Inabe, Pär-Anders Söderström, Hiroki Nishibata, Ayumi Yagi, I. Kojouharov, Roman Gernhäuser, F. C. L. Crespi, Daiki Nishimura, Jan Taprogge, K. Moschner, F. G. Kondev, H. Schaffner, H. S. Jung, Toshiyuki Kubo, F. Naqvi, G. Benzoni, Hiroyoshi Sakurai, Zs. Vajta, Zhengyu Xu, Zhenping Li, Anna Wendt, N. Fukuda, K. Yoshinaga, R. Orlandi, Zena Patel, D. Kameda, Gary Simpson, K. Steiger, G. J. Lane, Giuseppe Lorusso, Tadaaki Isobe, Chang-Bum Moon, A. Jungclaus, Hiroshi Suzuki, G. D. Kim, Toshiyuki Sumikama, Young-Ki Kim, Hiroyuki Takeda, Younghun Kwon, A. Montaner-Pizá, Jin Wu, Hiroshi Watanabe, H. Baba, Zs. Podolyák, N. Kurz, M. Niikura, and K. Y. Chae

Subjects
Physics, 010308 nuclear & particles physics, Yrast, Isotone, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Magic number (programming), Isotopes of palladium, Neutron number, 0103 physical sciences, Quadrupole, Level structure, Neutron, Atomic physics, 010306 general physics
Abstract

The level structures of the very neutron-rich nuclei $^{128}\mathrm{Pd}$ and $^{126}\mathrm{Pd}$ have been investigated for the first time. In the $r$-process waiting-point nucleus $^{128}\mathrm{Pd}$, a new isomer with a half-life of $5.8(8)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ is proposed to have a spin and parity of ${8}^{+}$ and is associated with a maximally aligned configuration arising from the ${g}_{9/2}$ proton subshell with seniority $\ensuremath{\upsilon}=2$. For $^{126}\mathrm{Pd}$, two new isomers have been identified with half-lives of 0.33(4) and $0.44(3)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$. The yrast ${2}^{+}$ energy is much higher in $^{128}\mathrm{Pd}$ than in $^{126}\mathrm{Pd}$, while the level sequence below the ${8}^{+}$ isomer in $^{128}\mathrm{Pd}$ is similar to that in the $N=82$ isotone $^{130}\mathrm{Cd}$. The electric quadrupole transition that depopulates the ${8}^{+}$ isomer in $^{128}\mathrm{Pd}$ is more hindered than the corresponding transition in $^{130}\mathrm{Cd}$, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number $N=82$ is fairly robust in the neutron-rich Pd isotopes.

Published
2013

36. Shape evolution in116,118Ru: Triaxiality and transition between the O(6) and U(5) dynamical symmetries

Author

Hyo Soon Jung, Hiroki Nishibata, T. Isobe, Shunji Nishimura, K. Steiger, H. Baba, Hirofumi Watanabe, F. Browne, Guillaume Gey, F. G. Kondev, Toshiyuki Kubo, G. J. Lane, Giuseppe Lorusso, G. D. Kim, Megumi Niikura, Zhengyu Xu, K. Y. Chae, F. Naqvi, Z. H. Li, P. A. Söderström, Naohito Inabe, Hiroyoshi Sakurai, Young-Ki Kim, G. Thiamova, Younghun Kwon, D. Kameda, N. Kurz, K. Yoshinaga, A. Montaner-Pizá, Naoki Fukuda, K. Moschner, F. C. L. Crespi, Zs. Podolyák, R. Orlandi, P. Doornenbal, H. Schaffner, Jan Taprogge, Gary Simpson, Anna Wendt, Ayumi Yagi, G. Benzoni, Toshiyuki Sumikama, Jin Wu, Hiroyuki Takeda, Roman Gernhäuser, Zena Patel, A. Jungclaus, Hiroshi Suzuki, I. Kojouharov, Atsuko Odahara, and Zs. Vajta

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Symmetry (physics), Classical mechanics, Neutron number, 0103 physical sciences, Homogeneous space, Interacting boson model, Atomic physics, Algebraic number, Nuclear Experiment, 010306 general physics, Spectroscopy, Ground state, Spin-½
Abstract

${}^{116}\mathrm{Ru}$ and ${}^{118}\mathrm{Ru}$ have been studied via $\ensuremath{\beta}$-delayed $\ensuremath{\gamma}$-ray spectroscopy of nuclei produced in fragmentation reactions at the Radioactive Ion-Beam Factory (RIBF) facility. Level schemes with positive-parity states up to spin $J=6$ have been constructed. The results have been discussed in terms of the interacting boson model, the algebraic collective model, and total Routhian surfaces. We conclude that the very neutron-rich nuclei still show many features associated with triaxial $\ensuremath{\gamma}$-soft nuclei, represented by the O(6) symmetry, but are approaching a spherical structure, the U(5) symmetry, with increasing neutron number towards the $N=82$ shell closure. In ${}^{118}\text{Ru}$, hints of a shape transition in the ground state have been observed.

Published
2013

37. Delayedγ-ray and conversion-electron spectroscopy ofA=97fission fragments

Author

N. Pillet, J.-M. Régis, Ulli Köster, C. Fransen, T. Materna, J. Le Bloas, T. Thomas, W. Rother, D. Wilmsen, M. Hackstein, M. Ramdhane, N. Warr, M. Pfeiffer, M. Rudigier, T. Malkiewicz, Guillaume Gey, A. Blazhev, Gary Simpson, J. M. Daugas, and J. Jolie

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Fission, 0103 physical sciences, Radiochemistry, 010306 general physics, 01 natural sciences, Electron spectroscopy
Published
2013

38. Gamma-ray Spectroscopy in the Vicinity of $^{108}$Zr

Author

Hirofumi Watanabe, F. Browne, Hiroyoshi Sakurai, Guillaume Gey, Naohito Inabe, F. Didierjean, Mana Tanaka, D. Kameda, N. Kurz, S. Lalkovski, P. H. Regan, Atsuko Odahara, I. Kojouharov, Hiroki Nishibata, P. Doornenbal, Z. H. Li, Raymond J. Carroll, T. Isobe, L. Sinclair, Zs. Podolyák, Nobuyuki Chiga, Stephen Rice, Oliver J. Roberts, Y. F. Fang, R. Daido, Jan Taprogge, P. A. Söderström, Shin-Ichiro Nishimura, Alison Bruce, Eiji Ideguchi, R. Lozeva, H. Baba, Toshiyuki Sumikama, T. Kubo, O. Wieland, Jin Wu, H. Schaffner, Zhengyu Xu, Giuseppe Lorusso, V. Werner, N. Naoki, Gary Simpson, Zena Patel, Hiroshi Suzuki, H. Takeda, I. Nishizuka, and Ayumi Yagi

Subjects
Nuclear physics, Physics, Fission, Detector, General Physics and Astronomy, Separator (oil production), Gamma spectroscopy, Scintillator, Nucleon, Beam (structure), Ionizing radiation
Abstract

The half-lives of $2^+_1$ states were measured for $^{102,104}$Zr and $^{106,108}$Mo to test a new implementation of a LaBr$_3$(Ce) array at the RIBF, RIKEN, Japan. The nuclei of interest were produced through the fission of a 345~MeV/nucleon $^{238}$U beam and selected by the BigRIPS separator. Fission fragments were implanted into the WAS3ABi active stopper, surrounding which, 18 LaBr$_3$(Ce) detectors provided fast $\gamma$-ray detection. Timing between the LaBr$_3$(Ce) array and plastic scintillators allowed for the measurement of half-lives of low-lying states. The preliminary results, which agree with literature values, are presented along with experimental details.

Published
2015

39. Isomer and beta decay spectroscopy in the132Sn region with EURICA

Author

A. Jungclaus, T. Isobe, Giuseppe Lorusso, J. M. Daugas, I. Kojouharov, Naohito Inabe, K. Yoshinaga, P. A. Söderström, D. Mücher, A. Montaner-Pizá, Zhengyu Xu, Hyo Soon Jung, Y. K. Kim, H. Suzuki, Hiroyoshi Sakurai, Anna Wendt, H. Baba, T. Kubo, Hiroki Nishibata, K. Moschner, G. D. Kim, Toshiyuki Sumikama, Gary Simpson, F. Browne, Young Kwan Kwon, Jinguang Wu, Guillaume Gey, S. Ilieva, Zs. Vajta, F. Drouet, Ayumi Yagi, H. Schaffner, S. Bönig, N. Fukuda, H. Takeda, Hiroshi Watanabe, S. Nishimura, D. Kameda, P. Doornenbal, K. Steiger, N. Kurz, Roman Gernhäuser, Z. H. Li, T. Kröll, Jan Taprogge, R. Orlandi, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Ministerio de Ciencia e Innovación (España), Lunardi, S, Bizzeti, PG, Kabana, S, Bucci, C, Chiari, M, Dainese, A, DiNezza, P, Menegazzo, R, Nannini, A, Signorini, C, and ValienteDobon, JJ

Subjects
Geography, Physics, QC1-999, Library science, Astronomy, Creative commons, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Spectroscopy, 7. Clean energy, ComputingMilieux_MISCELLANEOUS
Abstract

A. Jungclaus et al.; 4 págs.; 1 fig.; Open Access funded by Creative Commons Atribution Licence 2.0, The first EURICA campaign with high intensity Uranium beams took place at RIKEN in November/December 2012. Within this campaign experiment NP1112-RIBF85 was performed dedicated to the study of the isomeric and beta decays of neutronrich Cd, In, Sn and Sb isotopes towards and beyond the N=82 neutron shell closure. In this contribution we present a first status report of the analysis of the extensive data set obtained in this experiment. C Owned by the authors, published by EDP Sciences, 2014, This work has been supported by the Spanish Ministerio de Ciencia e Innovación under contracts FPA2009-13377-C02 and FPA2011-29854-C04.

Published
2014

40. Promptγ-ray spectroscopy of the neutron-rich124Cd

Author

C. Scholey, G. Thiamova, Sami Rinta-Antila, Paul Greenlees, Panu Ruotsalainen, M. Ramdhane, Jan Sarén, Andrej Herzan, R. Julin, Grégoire Kessedjian, S. Juutinen, T. Malkiewicz, Peter M. Jones, A. Lopez-Martens, Guillaume Gey, Juha Sorri, Pauli Peura, Ulrika Jakobsson, Mikael Sandzelius, K. Hauschild, C. Sage, F. Drouet, Juha Uusitalo, P. Rahkila, T. Grahn, Steffen Ketelhut, Paivi Nieminen, Gary Simpson, A. Vancraeyenest, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Triple coincidence, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], ta114, 010308 nuclear & particles physics, Fission, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, 7. Clean energy, 01 natural sciences, Engineering physics, Semiconductor detector, Nuclear physics, Isotopes of cadmium, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Spectroscopy, ComputingMilieux_MISCELLANEOUS
Abstract

Prompt γ -ray spectroscopy of neutron-rich cadmium isotopes has been performed. The nuclei of interest have been populated via a 25-MeV, proton-induced fission of the 238 U thick target and prompt γ -rays measured using the multi-detector HPGe array JUROGAM II. New high-spin decays have been observed and placed in the level scheme using triple coincidence gates. The experimental results are compared to shell-model calculations and show good agreement.

Published
2013

41. Gamma Spectroscopy of Low-energy Isomeric States in Neutron-rich Nuclei: 75Cu

Author

Georgi P. Georgiev, G. S. Simpson, F. Negoita, C. Petrone, R. Borcea, L. Gaudefroy, O. Sorlin, L. Caceres, R. Chevrier, C. Plaisir, O. Kamalou, Guillaume Gey, J. M. Daugas, S. Calinescu, M. Stanoiu, C. Borcea, F. Rotaru, and J. C. Thomas

Subjects
Nuclear physics, Physics, Low energy, 010308 nuclear & particles physics, 0103 physical sciences, General Physics and Astronomy, Gamma spectroscopy, Neutron, 010306 general physics, 01 natural sciences
Published
2013

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