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2. Production of $$^{178}$$Hfm2 and a simple chemical separation method for Hf recovery

Author

Nobuaki Imai, N. Kitamura, Shin'ichiro Michimasa, Susumu Shimoura, Yuki Yamaguchi, and Hiromitsu Haba

Subjects
Nuclear reaction, Materials science, Luminosity (scattering theory), Isotope, Health, Toxicology and Mutagenesis, Cyclotron, Public Health, Environmental and Occupational Health, Nuclear isomer, Pollution, Analytical Chemistry, law.invention, Nuclear Energy and Engineering, law, Radiology, Nuclear Medicine and imaging, Production (computer science), Irradiation, Atomic physics, Spectroscopy, Beam (structure)
Abstract

The nuclear isomer $$^{178}$$ Hfm2 enables various investigations owing to its unique properties. To study exotic nuclear reactions induced by $$^{178}$$ Hfm2, an isomeric target is the most effective option in terms of luminosity. However, this creates many challenges to overcome. One of the challenges is that nanogram quantities of the isomer are essential for fabricating a target. We conducted a pilot experiment to establish the method for isomer production, as the first step toward large-scale production at the Radioactive Isotope Beam Factory (RIBF), RIKEN. An $$\alpha$$ beam at 40 MeV supplied from the AVF cyclotron bombarded natural-abundance metallic Yb foils. Hf isotopes were extracted from the irradiated target by a new chemical separation method. We produced a sample containing $$10^{11}$$ atoms of $$^{178}$$ Hfm2, paving the way to future large-scale production at the RIBF.

Published
2021

3. MPV—Parallel Readout Architecture for the VME Data Acquisition System

Author

Shuichi Ota, Daiki Nishimura, Hidetada Baba, Takashi Ichihara, Susumu Shimoura, Juzo Zenihiro, A. O. Tokiyasu, S. Takeuchi, R. Yokoyama, H. M. Shimizu, T. Ohnishi, T. Isobe, K. Yoshida, and Yukinobu Watanabe

Subjects
Nuclear and High Energy Physics, business.industry, Computer science, Data acquisition, Nuclear Energy and Engineering, Backplane, Gate array, Eurocard, Systems architecture, Electrical and Electronic Engineering, business, Field-programmable gate array, Throughput (business), Computer hardware, VMEbus
Abstract

Mountable controller with parallelized VERSA Module Eurocard (VME) (MPV) is a VME-compatible system having a parallel readout architecture. This article presents the system architecture and its data acquisition performance. In this system, the readout sequence is implemented in a field-programmable gate array (FPGA) to achieve the ideal VME bus speed. Data from multiple VME slave modules are read out in parallel, merged, and sent to a server. Maximum data throughput of 400 Mbps was achieved. Thus, the MPV system can dramatically improve the performance of VME data acquisition systems.

Published
2021

5. Study of spin-isospin responses of radioactive nuclei with the background-reduced neutron spectrometer, PANDORA

Author

N. Fukuda, Takashi Nakamura, H. Sakai, Yohei Shimizu, J. Gibelin, Makoto Yasuda, Tomotsugu Wakasa, M. Nishimura, J. Gao, Masashige Matsumoto, S. Franchoo, H. Miki, H. Kasahara, T. Harada, Masaki Sasano, D. Tudor, Toshio Kobayashi, T. Isobe, G. G. Kiss, Tomohiro Uesaka, Yasuhiro Togano, Susumu Shimoura, Atsumi Saito, N. Zhang, I. C. Stefanescu, E. Takada, Zoltán Halász, L. Trache, Yuya Kubota, D. Kim, T. Shimada, Shoko Koyama, Y. Fujino, Juzo Zenihiro, Z. Korkulu, D. Inomoto, Zaihong Yang, H. Sato, H. N. Liu, A. Spiridon, M. Miwa, H. Suzuki, L. Stuhl, V. Panin, H. Baba, Yosuke Kondo, S. Park, K. Yoneda, T. Motobayashi, Y. L. Sun, T. Tomai, I. S. Hahn, Kentaro Yako, X. Sun, A. Kurihara, M.N. Harakeh, Y. Hirai, D. S. Ahn, A. I. Chilug, Hideaki Otsu, Hiroki Yamada, Shin'ichiro Michimasa, K. Yoshida, 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), 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), 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, Research unit Nuclear & Hadron Physics, 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 Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear and High Energy Physics, Nuclear Theory, n) reactions, Inverse-kinematics (p, n) reactions, 01 natural sciences, Low-energy neutron detector, Inverse-kinematics [formula omitted] reactions, Nuclear physics, 0103 physical sciences, Figure-of-Merit (FoM), Neutron detection, Neutron, 010306 general physics, Spin (physics), Nuclear Experiment, Instrumentation, Gamow-Teller transition, DETECTOR, Real-time pulse-shape discrimination, Physics, [PHYS]Physics [physics], Spin-isospin response, Spectrometer, 010308 nuclear & particles physics, Figure-of-Merit (RIM), Detector, PULSE-SHAPE DISCRIMINATION, PLASTIC SCINTILLATOR, Inverse-kinematics (p, Isospin, Ground state, Beam (structure)
Abstract

The status of a project to measure spin-isospin responses of neutron drip-line nuclei using a new low-energy neutron detector, PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition), is reported. The performance of PANDORA was characterized by the 6He(p,n)6Li reaction in inverse kinematics at the HIMAC facility in Chiba. Observation of the strong transition to the ground state in 6Li is discussed. Preliminary results of 11Li(p,n)11Be and 14Be(p,n)14B experiments in inverse kinematics at RI Beam Factory (RIBF) of RIKEN Nishina Center are also presented including the exotic decay channel of 11Be→9Li + d. Details of the experimental setup based on PANDORA and the SAMURAI large-acceptance magnetic spectrometer, as well as the combined data-acquisition system are described. The neutron-gamma discrimination capability of PANDORA was evaluated, Figure-of-Merit (FoM) values higher than those found in the literature for similar materials were derived from experimental data.

Published
2020

6. New energy-degrading beamline for in-flight RI beams, OEDO

Author

Seiya Hayakawa, H. Yamaguchi, Takashi Nakamura, N. Imai, Olga Beliuskina, Hiroyoshi Sakurai, Jongwon Hwang, Nobuyuki Chiga, Y. Yanagisawa, Yohei Shimizu, Yukinobu Watanabe, Shin'ichiro Michimasa, Masanori Dozono, Hideki Shimizu, Toshiyuki Sumikama, K. Chikaato, Masao Ohtake, P. Schrock, Y. X. Watanabe, Shuichi Ota, Kathrin Wimmer, Kentaro Yako, Koichi Yoshida, Maya Takechi, K. Kawata, H. Yoshida, S. Omika, N. Kitamura, H. Wang, Motonobu Takaki, Eiji Ideguchi, Chihiro Iwamoto, Liu Yang, Hiroshi Suzuki, Hiroyuki Takeda, Keita Nakano, Kazunari Yamada, K. Iribe, Hiroari Miyatake, Shoichiro Kawase, Hideaki Otsu, D. Nagae, Rieko Tsunoda, Kensuke Kusaka, X. Sun, Ryo Nakajima, Shoichiro Masuoka, Satoshi Takeuchi, D. S. Ahn, Takashi Teranishi, Masafumi Matsushita, Naoki Fukuda, Daisuke Suzuki, and Susumu Shimoura

Subjects
Superconductivity, Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Physics::Medical Physics, New energy, 01 natural sciences, Ion, Optics, Beamline, Magnet, 0103 physical sciences, Quadrupole, Physics::Accelerator Physics, 010306 general physics, business, Instrumentation
Abstract

The Optimized Energy Degrading Optics (OEDO) beamline was constructed at RIBF to produce slowed-down, well-focused radioactive-isotope beams at 10–50 MeV/u, and began operation in June 2017. We examined the performance of the OEDO system by decelerating high-energy medium-mass radioactive ions. The main components of the OEDO beamline are two superconducting quadrupole triplet magnets and one radio-frequency deflector. This paper introduces the unique design of the ion optics of the beamline and describes the achieved performance of the beamline in the commissioning and following physics experiments. We will discuss the properties of energy-degraded beams produced by the OEDO beamline by comparison of simulations and the achieved performance.

Published
2020

7. Continuum Strength of Direct Breakup Induced by External Isoscalar Field

Author

Akito Saito, M. Ito, Susumu Shimoura, and R. Nakamoto

Subjects
Physics, Field (physics), Quantum electrodynamics, Isoscalar, Nuclear Theory, Continuum (design consultancy), Bound state, Binary number, Wave function, Breakup, Scaling, Atomic and Molecular Physics, and Optics
Abstract

New formula to describe the non-resonant background strength in the binary breakup is considered on the basis of the Migdal-Watson (MW) formula. The background strength is assumed to be generated by the direct breakup, which is the one step transition from the initial bound state to the final continuum state. The strength of the direct breakup is evaluated by the complex scaling method (CSM). We have found that the extended MW formula, which is proposed in the present study, nicely reproduces the strength of the direct breakup calculated by CSM. The relation of the parameters newly introduced in the extended MW formula and the spatial size of the initial wave function is also discussed.

Published
2021

9. High-spin states in S35

Author

Shoji Nakamura, Yosuke Toh, K. Kisamori, Yuichi Hatsukawa, F. Azaiez, Yutaka Utsuno, I. Matea, Shin'ichiro Michimasa, Megumi Niikura, Ayumi Yagi, Mitsuo Koizumi, Rin Yokoyama, Hideo Harada, M. Sugawara, Daisuke Suzuki, Motoki Kobayashi, Nori Aoi, Kazuyoshi Furutaka, Noritaka Shimizu, D. Verney, Hiroki Nishibata, Hiroyuki Miya, Susumu Shimoura, T. Shizuma, Eiji Ideguchi, Motonobu Takaki, Shintaro Go, A. Kimura, and Fumito Kitatani

Subjects
Physics, Spin states, Condensed matter physics, 010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences
Published
2021

10. Three-body breakup of $^6$He and its halo structure

Author

Yuichi Ichikawa, K. Yoneda, Hiroyoshi Sakurai, T. Shinohara, T. Motobayashi, T. Shimamura, Y. Satou, T. Kobayshi, Y.L. Sun, Nori Aoi, Kazuyuki Ogata, Y. Kikuchi, Takashi Nakamura, Takuma Matsumoto, Takashi Sugimoto, Masamichi Ishihara, Kazuo Ieki, Yasuhiro Togano, Hideaki Otsu, Satoshi Takeuchi, Jenny Lee, Yosuke Kondo, Susumu Shimoura, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and 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

Subjects
Nuclear and High Energy Physics, Nuclear Theory, Halo nucleus, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear breakup, Nuclear physics, [formula omitted])X, 0103 physical sciences, Halo nuclei, Coulomb, Electric dipole response, Coulomb breakup, Neutron, 010306 general physics, Nuclear Experiment, Physics, 12 C( 6 He, Range (particle radiation), 208 Pb( 6 He, 010308 nuclear & particles physics, Scattering, 12C(6He, α+2n)X, Breakup, 208Pb(6He, lcsh:QC1-999, α+2n )X, Halo, Nucleon, 12C(6He, 208Pb(6He, α+2n)X, lcsh:Physics
Abstract

The Borromean halo nucleus 6He has been studied by a kinematically complete measurement of Coulomb and nuclear breakup into α + 2n on Pb and C targets at 70 MeV/nucleon. Fully quantum-mechanical four-body breakup calculations reproduce the energy and angular differential cross sections below E rel ∼ 1 MeV for both targets. The model used here reproduces the 6He ground-state properties as well as α-n and n-n scattering data and predicts an average opening angle 〈 θ n n 〉 of 68∘ between the two halo neutrons. However, the model underestimates the breakup cross sections for higher E rel , indicating a possible contribution from the inelastic breakup. Alternatively, we examine the empirically modified calculations that reproduce the energy-differential cross sections for a wide range of scattering angles for both targets. The extracted B(E1) peaks at E rel ∼ 1.4 MeV and amounts to 1.6(2) e2 fm2 for E rel ≤ 20 MeV, resulting 〈 θ n n 〉 = 56 − 10 + 9 degrees. In either interpretation, the current results show evidence of the dineutron spatial correlation in 6He.

Published
2021

11. Mapping of a New Deformation Region Around Ti62

Author

DeukSoon Ahn, Tatsuya Furuno, Hiroyuki Miya, G. P. A. Berg, Andreas Stolz, Susumu Shimoura, A. Mizukami, Kenichi Yoshida, Eiji Ideguchi, Hideyuki Sakai, Motonobu Takaki, H. Takeda, Y. Yanagisawa, Shin'ichiro Michimasa, Shuichi Ota, H. Nagakura, Naoki Fukuda, Yuya Kubota, Masafumi Matsushita, H. Oikawa, Toshiyuki Kubo, Takeo Kawabata, Hiroshi Suzuki, Tomohiro Uesaka, Satoshi Takeuchi, Shoichiro Kawase, Masanori Dozono, K. Kobayashi, R. Yokoyama, Y. Kiyokawa, Y. L. Yamaguchi, Y. Shimizu, H. Baba, D. Nishimura, Kentaro Yako, C. S. Lee, Hiroshi Tokieda, K. Kisamori, Naohito Inabe, and Motoki Kobayashi

Subjects
Materials science, Isotope, chemistry, Neutron number, Isotopes of vanadium, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, Scandium, Deformation (engineering), Beam (structure), Atomic mass, Titanium
Abstract

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

Published
2020

12. How Different is the Core of F25 from Og.s.24 ?

Author

W. Kim, Rin Yokoyama, K. Kisamori, S. S. Stepanyan, T. Kawahara, Naoki Fukuda, Tomohiro Uesaka, Hiroyuki Miya, D. Kameda, Kenichi Yoshida, Takashi Kubo, Shuichi Ota, Susumu Shimoura, Motonobu Takaki, Yukie Maeda, Hideyuki Sakai, A. Galindo-Uribarri, Kazuyuki Ogata, Shin'ichiro Michimasa, Tomotsugu Wakasa, Sanghoon Hwang, J. Yasuda, T. L. Tang, Yuya Kubota, Hiroshi Tokieda, Masanori Dozono, Kensuke Kusaka, Juzo Zenihiro, T. Fukunaga, Hiroshi Matsubara, Y. Yanagisawa, Didier Beaumel, Elizabeth Padilla-Rodal, A. Obertelli, Naohito Inabe, Hiroyuki Takeda, Motoki Kobayashi, C. S. Lee, T. Fujii, Takashi Wakui, Kentaro Yako, Tetsuo Noro, Satoshi Sakaguchi, Shoichiro Kawase, Masaki Sasano, and Hiroshi Suzuki

Subjects
Physics, Proton, 010308 nuclear & particles physics, General Physics and Astronomy, 01 natural sciences, 3. Good health, Core (optical fiber), Crystallography, medicine.anatomical_structure, Excited state, 0103 physical sciences, medicine, Neutron, Anomaly (physics), 010306 general physics, Ground state, Nuclear theory, Nucleus
Abstract

The structure of a neutron-rich ^{25}F nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A MeV in inverse kinematics. The sum of spectroscopic factors of π0d_{5/2} orbital is found to be 1.0±0.3. However, the spectroscopic factor with residual ^{24}O nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the ^{24}O core of ^{25}F nucleus significantly differs from a free ^{24}O nucleus, and the core consists of ∼35% ^{24}O_{g.s.}. and ∼65% excited ^{24}O. The result may infer that the addition of the 0d_{5/2} proton considerably changes neutron structure in ^{25}F from that in ^{24}O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Published
2020

13. 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

14. The OEDO Project: Production of Slowed-Down RI Beams at RIBF

Author

Susumu Shimoura and Shin'ichiro Michimasa

Subjects
Physics, Nuclear and High Energy Physics, Optics, 010308 nuclear & particles physics, business.industry, 0103 physical sciences, Separator (oil production), 010306 general physics, business, 01 natural sciences
Abstract

The “Optimized Energy-Degrading Optics” (OEDO) project [1, 2] has been promoted to develop slowed-down radioactive-isotope (RI) beams from fast fragments provided by the in-flight RI separator BigR...

Published
2018

15. Spallation reaction study for the long-lived fission products in nuclear waste: Cross section measurements for 137 Cs, 90 Sr and 107 Pd using inverse kinematics method

Author

Megumi Niikura, P. A. Söderström, DeukSoon Ahn, Shin'ichiro Michimasa, Hiroyuki Takeda, Yoshiaki Shiga, Giusseppe Lorusso, Yasushi Watanabe, Hideaki Otsu, Satoshi Takeuchi, T. Ozaki, Naoki Fukuda, Hiroshi Suzuki, Yukinobu Watanabe, Pieter Doornenbal, Hongwei Wang, Satoru Momiyama, Keita Nakano, Yosuke Kondo, Toshiyuki Sumikama, Teiichiro Matsuzaki, Koichi Yoshida, Hiroyoshi Sakurai, Shoichiro Kawase, Toshiyuki Kubo, Atsumi Saito, Kathrin Wimmer, Tatsuya Yamamoto, Yohei Shimizu, Takashi Nakamura, Nobuyuki Chiga, Yukie Maeda, Meiko Uesaka, Shigeru Kubono, A. Makinaga, Takeshi Saito, Susumu Shimoura, Tadahiro Kin, Tadaaki Isobe, Takashi Ando, Yasuhiro Togano, Masafumi Matsushita, Shunpei Koyama, S. Nagamine, Ryo Taniuchi, Shouhei Araki, Masayuki Aikawa, J. Tsubota, and S. Kawakami

Subjects
Fission products, Materials science, Nuclear transmutation, Proton, 010308 nuclear & particles physics, Radioactive waste, 01 natural sciences, Nuclear physics, Cross section (physics), Deuterium, 0103 physical sciences, Spallation, 010306 general physics, Long-lived fission product
Abstract

Spallation reaction study has been performed for the long-lived fission products 137Cs, 90Sr and 107Pd. Isotopic cross sections on proton and deuteron were obtained by using the inverse kinematics technique at the RIKEN Radioactive Isotope Beam Factory. It was found that the deuteron-induced cross sections are larger than the proton-induced ones for the light-mass products. The experimental data were compared with the SPACS semi-empirical parameterization and a theoretical calculation including both the intra-nuclear cascade and evaporation models by the PHITS transport code. It was found that the spallation reaction could be a promising mechanism for the transmutation of 137Cs and 90Sr due to the large total cross section.

Published
2017

16. Observation of isoscalar and isovector dipole excitations in neutron-rich 20 O

Author

K. Yoneda, Ryo Taniuchi, Susumu Shimoura, H. Baba, T. Murakami, J. Tsubota, R. Avigo, Hideaki Otsu, Yosuke Kondo, Agnese Giaz, Noritsugu Nakatsuka, C. Caesar, Takeo Kawabata, F. Camera, S. Ceruti, Y. L. Yamaguchi, Hooi Jin Ong, Kathrin Wimmer, A. Horvat, Juzo Zenihiro, J. Tscheuschner, T. Ozaki, Toshiyuki Sumikama, Takashi Nakamura, B. Million, H. Wang, F. Schindler, Hiroyuki Takeda, A. Bracco, Heiko Scheit, Hiroyoshi Sakurai, Tsuyoshi Ohnishi, Shoko Koyama, M. Shikata, I. Syndikus, N. Imai, T. Motobayashi, Kazuo Ieki, T. Inakura, Yoshiaki Shiga, V. Derya, Shuichi Ota, P. Doornenbal, Shoichiro Masuoka, Yasuhiro Togano, P. Schrock, Masafumi Matsushita, S. Michimasa, Oliver Wieland, Shao-Long Chen, David Steppenbeck, Atsumi Saito, Satoshi Takeuchi, S.R. Banerjee, Thomas Aumann, M. Kurata-Nishimura, Atsushi Tamii, and Nagao Kobayashi

Subjects
O20, Nuclear and High Energy Physics, Inelastic α scattering, Isoscalar, Nuclear Theory, Inelastic alpha scattering, 01 natural sciences, Nuclear physics, 0103 physical sciences, ddc:530, Neutron, Born approximation, 010306 general physics, Physics, Isovector, 010308 nuclear & particles physics, Inelastic α scattering, Low-energy dipole excitation, Virtual-photon excitation, lcsh:QC1-999, Dipole, O-20, Isospin, Excited state, (20)O, Sum rule in quantum mechanics, Atomic physics, lcsh:Physics
Abstract

The isospin characters of low-energy dipole excitations in neutron-rich unstable nucleus 20O were investigated, for the first time in unstable nuclei. Two spectra obtained from a dominant isovector probe (View the MathML sourceO20+Au) and a dominant isoscalar probe (View the MathML sourceO20+α) were compared and analyzed by the distorted-wave Born approximation to extract independently the isovector and isoscalar dipole strengths. Two known 1−1− states with large isovector dipole strengths at energies of 5.36(5) MeV (View the MathML source11−) and 6.84(7) MeV (View the MathML source12−) were also excited by the isoscalar probe. These two states were found to have different isoscalar dipole strengths, 2.70(32)% (View the MathML source11−) and 0.67(12)% (View the MathML source12−), respectively, in exhaustion of the isoscalar dipole-energy-weighted sum rule. The difference in isoscalar strength indicated that they have different underlying structures. ispartof: Physics Letters B vol:768 pages:387-392 status: published

Published
2017

17. Isotope production in proton-, deuteron-, and carbon-induced reactions on Nb93 at 113 MeV/nucleon

Author

Kathrin Wimmer, Shigeru Kubono, Hiroyoshi Sakurai, Yasushi Watanabe, J. Tsubota, Yoshiaki Shiga, Atsumi Saito, D. S. Ahn, Pieter Doornenbal, A. Makinaga, Yukinobu Watanabe, Masayuki Aikawa, Toshiyuki Kubo, Naoki Fukuda, Tadaaki Isobe, T. Ozaki, P. A. Söderström, Yasuhiro Togano, Hiroyuki Takeda, Shin'ichiro Michimasa, S. Kawakami, Masafumi Matsushita, Sidong Chen, M. Shikata, Nobuyuki Chiga, Susumu Shimoura, Tadahiro Kin, Meiko Uesaka, Takeshi Saito, Satoshi Takeuchi, Hiroshi Suzuki, Toshiyuki Sumikama, Satoru Momiyama, Yosuke Kondo, Koichi Yoshida, Takashi Nakamura, Shoichiro Kawase, Hongwei Wang, Yohei Shimizu, Yukie Maeda, Takashi Ichihara, Shouhei Araki, Teiichiro Matsuzaki, Ryo Taniuchi, Hideaki Otsu, Tatsuya Yamamoto, Megumi Niikura, Shunpei Koyama, S. Nagamine, and Keita Nakano

Subjects
Nuclear physics, Physics, Isotope, Deuterium, Proton, Neutron number, Nuclear data, Spallation, Atomic number, Nucleon
Abstract

Isotope-production cross sections for p-, d-, and C-induced spallation reactions on Nb93 at 113 MeV/nucleon were measured using the inverse-kinematics method employing secondary targets of CH2, CD2, and C. The measured cross sections for Mo90, Nb90, Y86,88 produced by p-induced reactions were found to be consistent with those measured by the conventional activation method. We performed benchmark tests of the reaction models INCL-4.6, JQMD, and JQMD-2.0 implemented in the Particle and Heavy Ion Transport code System (PHITS) and of the nuclear data libraries JENDL-4.0/HE, TENDL-2017, and ENDF/B-VIII.0. The model calculations also showed generally good agreement with the measured isotope-production cross sections for p-, d-, and C-induced reactions. It also turns out that, among the three nuclear data libraries, JENDL-4.0/HE provides the best agreement with the measured data for the p-induced reactions. We compared the present Nb93 data with the Zr93 data, that were measured previously by the same inverse kinematics method (Kawase et al., Prog. Theor. Exp. Phys. 2017, 093D03 (2017)2050-391110.1093/ptep/ptx110), with particular attention to the effect of neutron-shell closure on isotope production in p- and d-induced spallation reactions. The isotopic distributions of the measured production cross sections in the Zr93 data showed noticeable jumps at neutron number N=50 in the isotopic chains of ΔZ=0 and -1, whereas no such jump appeared in isotopic chain of ΔZ=0 in the Nb93 data. From INCL-4.6 + GEM calculations, we found that the jump formed in the evaporation process is smeared out by the intranuclear cascade component in Nb91 produced by the Nb93(p,p2n) and (d,d2n) reactions on Nb93. Moreover, for Nb93, the distribution of the element-production cross sections as a function of the change in proton number ΔZ is shifted to smaller ΔZ than for Zr93, because the excited Nb prefragments generated by the cascade process are more likely to emit protons than the excited Zr prefragments, due to the smaller proton-separation energies of the Nb isotopes.

Published
2019

18. Angle-tunable wedge degrader for an energy-degrading RI beamline

Author

Susumu Shimoura, P. Schrock, Jongwon Hwang, Hiroyoshi Sakurai, Motonobu Takaki, Chihiro Iwamoto, Kensuke Kusaka, Toshiyuki Sumikama, Hideaki Otsu, N. Kitamura, Yoshiyuki Yanagisawa, Koichi Yoshida, S. Michimasa, Rieko Tsunoda, Olga Beliuskina, Masanori Dozono, Nobuaki Imai, Hiroyuki Takeda, Kentaro Yako, Masao Ohtake, K. Kawata, Shoichiro Masuoka, Kathrin Wimmer, Shoichiro Kawase, Hiroshi Suzuki, D. S. Ahn, Shinsuke Ota, and Naoki Fukuda

Subjects
Physics, Optics, Beamline, business.industry, General Physics and Astronomy, business, Wedge (geometry)
Published
2019

19. OEDO, the energy-degrading beamline at RI Beam Factory

Author

Yohei Shimizu, Shoichiro Masuoka, Masanori Dozono, Hiroari Miyatake, Takashi Teranishi, Satoshi Takeuchi, Nobuaki Imai, Kazunari Yamada, Kentaro Yako, Kensuke Kusaka, Jongwon Hwang, Masao Ohtake, Daisuke Nagae, Yutaka X. Watanabe, Toshiyuki Sumikama, Seiya Hayakawa, Hiroyuki Takeda, Yoshiyuki Yanagisawa, Keita Nakano, Hideaki Otsu, Shunichiro Omika, Ryo Nakajima, Koichi Yoshida, Xiaohui Sun, H. Yamaguchi, Maya Takechi, He Wang, Nobuyuki Chiga, D. S. Ahn, Yukinobu Watanabe, Hiroshi Suzuki, Takashi Nakamura, Olga Beliuskina, Susumu Shimoura, K. Kawata, Masafumi Matsushita, Shoichiro Kawase, Lei Yang, N. Kitamura, S. Michimasa, Daisuke Suzuki, Kathrin Wimmer, Chihiro Iwamoto, Motonobu Takaki, Rieko Tsunoda, Hiroya Yoshida, Eiji Ideguchi, Kotaro Iribe, P. Schrock, Naoki Fukuda, K. Chikaato, Hideki Shimizu, Shinsuke Ota, and Hiroyoshi Sakurai

Subjects
Physics, Optics, Beamline, business.industry, General Physics and Astronomy, Factory (object-oriented programming), business, Beam (structure), Energy (signal processing)
Published
2019

20. Coulomb breakup reactions of 93,94Zr in inverse kinematics

Author

Satoru Momiyama, Hideaki Otsu, Yosuke Kondo, J. Tsubota, Takeshi Saito, Sidong Chen, Shoichiro Kawase, Shin'ichiro Michimasa, Takashi Nakamura, Shunpei Koyama, Shigeru Kubono, Hiroyuki Takeda, M. Shikata, S. Nagamine, Ryo Taniuchi, Tadaaki Isobe, Nobuyuki Chiga, Takashi Ando, Pieter Doornenbal, Keita Nakano, Hiroyoshi Sakurai, Yasuhiro Togano, Meiko Uesaka, Toshiyuki Sumikama, Koichi Yoshida, P. A. Söderström, D. S. Ahn, Yohei Shimizu, Hiroshi Suzuki, A. Makinaga, Yasushi Watanabe, Megumi Niikura, Tatsuya Yamamoto, Shuichiro Ebata, T. Ozaki, Hongwei Wang, Masayuki Aikawa, Yoshiaki Shiga, Atsumi Saito, S. Kawakami, Masafumi Matsushita, Kathrin Wimmer, Yukinobu Watanabe, Kazuyuki Ogata, Susumu Shimoura, Yukie Maeda, Tadahiro Kin, Shohei Araki, Naoki Fukuda, Teiichiro Matsuzaki, and Satoshi Takeuchi

Subjects
Physics, Classical mechanics, Inverse kinematics, Coulomb, General Physics and Astronomy, Breakup
Published
2019

22. Energy-control and novel particle-identification methods combined with range in a multi-sampling ionization chamber for experiments using slowed-down RI beams

Author

Shin'ichiro Michimasa, Hiroyoshi Sakurai, Keita Nakano, T. Tomai, Shigeru Kubono, Shoichiro Kawase, K. Chikaato, Kenichi Yoshida, Y. Shimizu, Yasuhiro Togano, Yukinobu Watanabe, Naoki Fukuda, Hiroyuki Takeda, Masafumi Matsushita, Maya Takechi, A. Hirayama, J. Amano, H. Suzuki, Susumu Shimoura, Satoshi Takeuchi, H. W. Wang, Naohito Inabe, J. Suwa, Hideaki Otsu, Toshiyuki Sumikama, Nobuyuki Chiga, Atsumi Saito, and D. S. Ahn

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Spectrometer, 010308 nuclear & particles physics, 01 natural sciences, Particle identification, Momentum, Dipole magnet, 0103 physical sciences, Ionization chamber, Physics::Accelerator Physics, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Instrumentation, Beam (structure)
Abstract

A method for controlling the energy of slowed-down RI beams with the goal energy of 20 MeV/u was developed at the RIKEN RI Beam Factory. The 93Zr beam energy was successfully tuned to 20.2 MeV/u in a single step by adjusting its momentum selected by the first dipole magnet after a primary target. A method for particle identification was developed for the secondary reaction fragments at 50 MeV/u. The dispersive mode was applied to the ZeroDegree spectrometer to measure the momentum at the final focus F11. The reaction fragments were stopped in the multi-sampling ionization chamber (MUSIC) placed at F11, which measured the Δ E − E of the beam particles. In addition, the range R in MUSIC was determined with a resolution of 1.4 mm ( σ ) by using the energy ratio obtained from multi-sampled energy deposits. The atomic number was determined from the E − R correlation with a resolution of 0.15 ( σ ). To distinguish the charge state of the RI beam after the secondary reaction target, the range with the correction for the β dependence was combined with the mass-to-charge ratio determined from the time-of-flight and magnetic-rigidity measurements. A 5.6 σ separation was obtained between 92Zr 40 + and 90Zr 39 + using these two values.

Published
2021

23. Performance of the OEDO beamline

Author

Eiji Ideguchi, Naoki Fukuda, Hiroyoshi Sakurai, Jongwon Hwang, Masanori Dozono, D. S. Ahn, Kazunari Yamada, N. Kitamura, H. Wang, Hiroshi Suzuki, Hideki Shimizu, Susumu Shimoura, Chihiro Iwamoto, Liu Yang, K. Iribe, K. Chikaato, Hiroyuki Takeda, Seiya Hayakawa, Kensuke Kusaka, K. Kawata, Yukinobu Watanabe, Nobuyuki Chiga, H. Yamaguchi, Ryo Nakajima, H. Yoshida, Takashi Nakamura, Toshiyuki Sumikama, Y. Yanagisawa, N. Imai, Koichi Yoshida, Shin'ichiro Michimasa, Olga Beliuskina, S. Omika, Daisuke Suzuki, Shuichi Ota, Masafumi Matsushita, Kentaro Yako, Keita Nakano, Shoichiro Kawase, Yohei Shimizu, P. Schrock, Maya Takechi, Hironao Miyatake, Kathrin Wimmer, Rieko Tsunoda, Masao Ohtake, X. Sun, Takashi Teranishi, Hideaki Otsu, Motonobu Takaki, Satoshi Takeuchi, D. Nagae, Y. X. Watanabe, and Shoichiro Masuoka

Subjects
History, Engineering, Thesaurus (information retrieval), Information retrieval, Beamline, business.industry, Physics::Accelerator Physics, Nuclear Experiment, business, Computer Science Applications, Education
Abstract

The OEDO (Optimized Energy Degrading Optics for RI beam) beamline has been developed to obtain low-energy (10 – 50 MeV/u) RI beams by slowing down the secondary beams at RIBF, RIKEN. Such beams are useful probes to investigate nuclear structure by means of nucleon transfer and Coulomb excitation reactions. The beamline is designed to produce a well-focused beam of small energy spread with the help of the angle-tuneable wedge degrader and the radio-frequency deflector. The commissioning and first physics experiments using the OEDO beamline were carried out in 2017. OEDO successfully provided the energy-degraded beams of Se, Zr, and Pd. Its performance including the optics and transmission was evaluated using those experimental data and it functions properly as designed. We expect that our novel beamline shed a light on the experimental approaches involving nuclear reactions at several tens of MeV/u to expand our knowledge of nuclei far beyond the line of stability.

Published
2020

24. Study of spin-isospin response of 11Li neutron-drip-line nucleus with PANDORA

Author

Masaki Sasano, M. Miwa, T. Kobayashi, I. C. Stefanescu, D. Tudor, Tomohiro Uesaka, T. Isobe, K. Yoneda, D. Inomoto, Zaihong Yang, M. Nishimura, L. Stuhl, H. Baba, I. S. Hahn, D. Kim, K. Yoshida, A. I. Chilug, Y. Fujino, H. Suzuki, H. Sato, Yosuke Kondo, Zoltán Halász, H. Kasahara, Kentaro Yako, Tomotsugu Wakasa, Yasuhiro Togano, G. G. Kiss, T. Motobayashi, T. Shimada, Shin'ichiro Michimasa, X. Sun, Naoki Fukuda, Juzo Zenihiro, H. N. Liu, Takashi Nakamura, S. Park, Masashige Matsumoto, H. Miki, Y. Hirai, V. Panin, Hiroki Yamada, A. Spiridon, T. Tomai, Susumu Shimoura, Y. L. Sun, D. S. Ahn, M. N. Harakeh, H. Sakai, Makoto Yasuda, A. Kurihara, Atsumi Saito, N. Zhang, L. Trache, Yuya Kubota, J. Gibelin, Yohei Shimizu, S. Franchoo, Hideaki Otsu, J. Gao, Shoko Koyama, Z. Korkulu, T. Harada, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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, 010308 nuclear & particles physics, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computer Science Applications, Education, Nuclear physics, medicine.anatomical_structure, Isospin, 0103 physical sciences, medicine, Nuclear drip line, Nuclear Experiment, 010306 general physics, Nucleus, Spin-½
Abstract

The spin-isospin responses of the 11Li drip-line nucleus has been measured. Preliminary results of the 11Li(p, n)11Be experiment in inverse kinematics at RI Beam Factory (RIBF) of RIKEN Nishina Center are presented including the observation of 1n, 2n, t, d, 2α and 6He+α decay channels of 11Be reaction product. Details of the experimental setup based on PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition) low-energy neutron detector and the SAMURAI large-acceptance magnetic spectrometer are described.

Published
2020

25. Inverse kinematics (p,n) reactions studies using the WINDS slow neutron detector and the SAMURAI spectrometer

Author

H. Sato, Masaki Sasano, J. Yasuda, K. Kisamori, N. Fukuda, Shuichi Ota, Toshio Kobayashi, Shunpei Koyama, M. Kurata-Nishimura, Noritsugu Nakatsuka, T. Motobayashi, Juzo Zenihiro, M. Kaneko, D. Kameda, Remco Zegers, D. Mücher, Takashi Nakamura, Yosuke Kondo, Masanori Dozono, Naohiro Inabe, W. Chao, Yuya Kubota, J. W. Lee, T. Murakami, A. Krasznahorkay, G. Jhang, Susumu Shimoura, J. Tsubota, H. Suzuki, Tomohiro Uesaka, Motoki Kobayashi, M. Sako, C. S. Lee, Motonobu Takaki, M. Shikata, Hiroshi Tokieda, E. Milman, H. Sakai, Daniel Bazin, Yohei Shimizu, H. Otsu, Hidetada Baba, Tomotsugu Wakasa, Tadaaki Isobe, Yasuhiro Togano, T. Tako, S. Reichert, Kentaro Yako, W. Powell, Shin'ichiro Michimasa, Shoichiro Kawase, S. Tangwancharoen, L. Stuhl, V. Panin, Toshiyuki Sumikama, Hiroyuki Takeda, Yohei Matsuda, K. Yoneda, Toshiyuki Kubo, Satoshi Sakaguchi, and N. Kobayashi

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, 01 natural sciences, Neutron temperature, Nuclear physics, Time of flight, Recoil, 0103 physical sciences, Neutron detection, Neutron, Atomic number, Nuclear Experiment, 010306 general physics, Instrumentation, Excitation
Abstract

We have combined the low-energy neutron detector WINDS (Wide-angle Inverse-kinematics Neutron Detectors for SHARAQ) and the SAMURAI spectrometer at RIKEN Nishina Center RI Beam Factory (RIBF) in order to perform ( p , n ) reactions in inverse kinematics for unstable nuclei in the mass region around A ∼ 100 . In this setup, WINDS is used for detecting recoil neutrons and the SAMURAI spectrometer is used for tagging decay channel of heavy residue. The first experiment by using the setup was performed to study Gamow–Teller transitions from 132 Sn in April 2014. The atomic number Z and mass-to-charge ratio A / Q of the beam residues were determined from the measurements of time of flight, magnetic rigidity and energy loss. The obtained A / Q and Z resolutions were σ A / Q = 0.14 % and σ Z = 0.22 , respectively. Furthermore, owing to the large momentum acceptance ( 50 % ) of SAMURAI, the beam residues associated with the γ , 1n and 2n decay channel were measured in the same magnetic field setting. The kinematic loci of the measured recoil neutron energy and laboratory angle are clearly seen. It shows that the excitation energy up to about 20 MeV can be reconstructed.

Published
2016

26. Isotope-production cross sections of residual nuclei in proton- and deuteron-induced reactions on 93Zr at 50 MeV/u

Author

Hiroshi Suzuki, Akihiro Hirayama, Takashi Nakamura, Hideaki Otsu, Yoshiki Soudo, Pär-Anders Söderström, Pieter Doornenbal, Daisuke Suzuki, T. Tomai, D. S. Ahn, Ian Murray, Masahiro Yasuda, Shin'ichiro Michimasa, Shigeru Kubono, Yosuke Kondo, Sidong Chen, Susumu Shimoura, S. Kawakami, Shoichiro Kawase, Tadaaki Isobe, Hiromi Sato, Hiroyuki Takeda, Yasuhiro Togano, Naoki Fukuda, Yukinobu Watanabe, Ryohei Hosoda, Shunpei Koyama, Junki Suwa, Hiroki Yamada, Yukie Maeda, Hidetada Baba, Toshiyuki Sumikama, Ryo Nakajima, Koichi Yoshida, Xiaohui Sun, Atsumi Saito, Shoichiro Masuoka, Keita Nakano, Satoshi Takeuchi, Nobuyuki Chiga, Hongwei Wang, Yohei Shimizu, Takeshi Saito, K. Chikaato, Martha Liliana Cortes, T. Ozaki, Maya Takechi, Megumi Niikura, and Hiroyoshi Sakurai

Subjects
Physics, Proton, Isotope, QC1-999, Nuclear Theory, Residual, Nuclear physics, Deuterium, Incident energy, Heavy ion, Nuclear Experiment, Nucleon, Beam (structure)
Abstract

The isotope-production cross sections in p- and d-induced reactions on 93Zr at approximately 50 MeV/nucleon were measured by using the inverse-kinematics method at RIKEN RI Beam Factory. The measured data were compared with the previous experimental 93Zr + p, d at 105 and 209 MeV/nucleon data. This comparison represents that the isotopic distribution of production cross sections at 51 MeV p-induced reaction is appreciably different from those at 105 and 209 MeV. On the other hand, these three data sets show that the shape of isotopic distribution is similar in the case of the d-induced reaction. Also, the measured production cross sections were compared with the theoretical model calculations with Particle and Heavy Ion Transport code System (PHITS) version 3.10 in order to investigate the reproducibility of the models implemented in PHITS. The calculations well reproduced the experimental data even in such low incident energy, while several discrepancies were still seen as in the p- and d-induced reactions at 105 and 209 MeV/nucleon.

Published
2020

27. Spallation reaction study for long-lived fission products in nuclear waste

Author

Hideaki Otsu, J. Tsubota, Takeshi Saito, Yukie Maeda, Megumi Niikura, H. Wang, Atsumi Saito, Pär-Anders Söderström, T. Ozaki, Hiroyuki Takeda, Ryo Taniuchi, Tatsuya Yamamoto, Nobuyuki Chiga, M. Shikata, Yohei Shimizu, Pieter Doornenbal, Meiko Uesaka, Toshiyuki Sumikama, Yoshiaki Shiga, Satoshi Takeuchi, Shigeru Kubono, Hiroshi Suzuki, Koichi Yoshida, S. Kawakami, Yukinobu Watanabe, Keita Nakano, Shouhei Araki, Satoru Momiyama, Yosuke Kondo, Shunpei Koyama, DeukSoon Ahn, Masafumi Matsushita, Shoichiro Kawase, S. Nagamine, Teiichiro Matsuzaki, Kathrin Wimmer, Yasushi Watanabe, Naoki Fukuda, Hiroyoshi Sakurai, A. Makinaga, Takashi Nakamura, Susumu Shimoura, Tadahiro Kin, Tadaaki Isobe, Takashi Ando, Yasuhiro Togano, Shin ichiro Michimasa, Sidong Chen, and Masayuki Aikawa

Subjects
Nuclear fission product, Materials science, Proton, Nuclear transmutation, 010308 nuclear & particles physics, Physics, QC1-999, Nuclear Theory, Radioactive waste, 01 natural sciences, Nuclear physics, Deuterium, 0103 physical sciences, Physics::Accelerator Physics, Spallation, Nuclear Experiment, 010306 general physics, Long-lived fission product, Nucleon
Abstract

Spallation reaction for the long-lived fission product 107Pd has been studied for the purpose of nuclear waste transmutation. The isotopic-distribution cross sections on both proton and deuteron were obtained at 118 MeV/nucleon in inverse kinematics at the RIKEN Radioactive Isotope Beam Factory. A large cross-section difference was found between the proton and deuteron results for the light-mass products. The data were compared with the SPACS semi-empirical parameterization and the PHITS calculations including both the intranuclear cascade and evaporation processes. In addition, the potential of spallation reaction for transmutation of 107Pd is discussed.

Published
2020

28. Direct reactions as quantum probes for nuclei

Author

Susumu Shimoura

Subjects
Physics, Imagination, Thesaurus (information retrieval), media_common.quotation_subject, Complex system, General Physics and Astronomy, 01 natural sciences, Theoretical physics, 0103 physical sciences, Scattering theory, Nuclear Experiment, 010306 general physics, Quantum, media_common
Abstract

Direct reactions are important and useful tools for obtaining information on nuclear properties. Basic quantum scattering theories, their features and underlying pictures are presented and discussed. New aspects using rare-isotope beams are also introduced.

Published
2018

29. Extraction of the Landau-Migdal Parameter from the Gamow-Teller Giant Resonance in Sn132

Author

Hiroshi Tokieda, Hiroyuki Takeda, Masaki Sasano, D. Muecher, M. Shikata, K. Kisamori, D. Kameda, Tomohiro Uesaka, G. Jhang, W. Chao, M. Kurata-Nishimura, M. Kaneko, Jongmin Lee, S. Reichert, H. Sakai, K. Yoneda, Toshiyuki Kubo, W. Powell, R. G. T. Zegers, H. Baba, Yohei Matsuda, Tadaaki Isobe, Nagao Kobayashi, D. Bazin, J. Yasuda, Yosuke Kondo, Toshio Kobayashi, Kentaro Yako, Tomotsugu Wakasa, Noritsugu Nakatsuka, Yasuhiro Togano, T. Motobayashi, Shin'ichiro Michimasa, Juzo Zenihiro, H. Sato, S. Tangwancharoen, Takashi Nakamura, J. Tsubota, A. Krasznahorkay, Susumu Shimoura, C. S. Lee, E. Milman, Motonobu Takaki, L. Stuhl, V. Panin, Toshiyuki Sumikama, N. Fukuda, Shuichi Ota, Yuya Kubota, Yohei Shimizu, T. Murakami, Satoshi Sakaguchi, Hideaki Otsu, T. Tako, M. Sako, Motoki Kobayashi, Shoko Koyama, Naohito Inabe, Masanori Dozono, and H. Suzuki

Subjects
Physics, Pion, 010308 nuclear & particles physics, Giant resonance, 0103 physical sciences, General Physics and Astronomy, Sum rule in quantum mechanics, Atomic physics, 010306 general physics, Nuclear matter, 01 natural sciences, Excitation
Abstract

The key parameter to discuss the possibility of the pion condensation in nuclear matter, i.e., the so-called Landau-Migdal parameter g^{'}, was extracted by measuring the double-differential cross sections for the (p,n) reaction at 216 MeV/u on a neutron-rich doubly magic unstable nucleus, ^{132}Sn with the quality comparable to data taken with stable nuclei. The extracted strengths for Gamow-Teller (GT) transitions from ^{132}Sn leading to ^{132}Sb exhibit the GT giant resonance (GTR) at the excitation energy of 16.3±0.4(stat)±0.4(syst) MeV with the width of Γ=4.7±0.8 MeV. The integrated GT strength up to E_{x}=25 MeV is S_{GT}^{-}=53±5(stat)_{-10}^{+11}(syst), corresponding to 56% of Ikeda's sum rule of 3(N-Z)=96. The present result accurately constrains the Landau-Migdal parameter as g^{'}=0.68±0.07, thanks to the high sensitivity of the GTR energy to g^{'}. In combination with previous studies on the GTR for ^{90}Zr and ^{208}Pb, the result of this work shows the constancy of this parameter in the nuclear chart region with (N-Z)/A=0.11 to 0.24 and A=90 to 208.

Published
2018

30. Magic Nature of Neutrons in Ca54 : First Mass Measurements of Ca55–57

Author

Y. Shimizu, Susumu Shimoura, Masafumi Matsushita, Eiji Ideguchi, Yuya Kubota, K. Kobayashi, Andreas Stolz, H. Baba, Hiroshi Tokieda, Naoki Fukuda, R. Yokoyama, Y. L. Yamaguchi, Hideyuki Sakai, Takeo Kawabata, Kentaro Yako, Toshiyuki Kubo, Daiki Nishimura, Tomohiro Uesaka, Tatsuya Furuno, Y. Yanagisawa, Shuichi Ota, H. Nagakura, DeukSoon Ahn, Kenichi Yoshida, Motoki Kobayashi, C. S. Lee, K. Kisamori, Hiroyuki Miya, A. Mizukami, Motonobu Takaki, H. Oikawa, Masanori Dozono, H. Takeda, Shin'ichiro Michimasa, Naohito Inabe, Hiroshi Suzuki, Satoshi Takeuchi, Shoichiro Kawase, Y. Kiyokawa, and G. P. A. Berg

Subjects
Physics, 010308 nuclear & particles physics, Band gap, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Atomic mass, Isotopes of calcium, Atomic orbital, Neutron number, 0103 physical sciences, Neutron, MAGIC (telescope), Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at the RIKEN Radioactive Isotope Beam Factory by using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{55-57}Ca are determined for the first time to be -18650(160), -13510(250), and -7370(990) keV, respectively. We examine the emergence of neutron magicity at N=34 based on the new atomic masses. The new masses provide experimental evidence for the appearance of a sizable energy gap between the neutron 2p_{1/2} and 1f_{5/2} orbitals in ^{54}Ca, comparable to the gap between the neutron 2p_{3/2} and 2p_{1/2} orbitals in ^{52}Ca. For the ^{56}Ca nucleus, an open-shell property in neutrons is suggested.

Published
2018

31. 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

32. Excitation of the Isovector Spin Monopole Resonance via the Exothermic Zr90(N12,C12) Reaction at 175 MeV/u

Author

Naoki Fukuda, Y. Yanagisawa, Remco Zegers, Kenichi Yoshida, Tomohiro Uesaka, Hiroaki Matsubara, Satoshi Sakaguchi, Shin'ichiro Michimasa, G. P. A. Berg, Naohito Inabe, H. W. Wang, Shoichiro Kawase, Kenjiro Miki, Shumpei Noji, Motonobu Takaki, Yukie Maeda, Hiroyuki Takeda, Hiroshi Tokieda, Nori Aoi, Masanori Dozono, K. Yako, N. Yokota, Toshiyuki Kubo, Y. Kikuchi, K. Kisamori, Satoshi Takeuchi, D. Kameda, Yoshiko Sasamoto, Takeo Kawabata, Hiroyuki Miya, Shuichi Ota, P. Doornenbal, Hideyuki Sakai, Susumu Shimoura, Tsuyoshi Ohnishi, H. Baba, and H. Miyasako

Subjects
Exothermic reaction, Physics, Isovector, 010308 nuclear & particles physics, Nuclear Theory, Magnetic monopole, General Physics and Astronomy, Resonance, Nuclear matter, 01 natural sciences, Spectral line, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Excitation
Abstract

The (^{12}N, ^{12}C) charge-exchange reaction at 175 MeV/u was developed as a novel probe for studying the isovector spin giant monopole resonance (IVSMR), whose properties are important for better understanding the bulk properties of nuclei and asymmetric nuclear matter. This probe, now available through the production of ^{12}N as a secondary rare-isotope beam, is exothermic, is strongly absorbed at the surface of the target nucleus, and provides selectivity for spin-transfer excitations. All three properties enhance the excitation of the IVSMR compared to other, primarily light-ion, probes, which have been used to study the IVSMR thus far. The ^{90}Zr(^{12}N,^{12}C) reaction was measured and the excitation energy spectra up to about 70 MeV for both the spin-transfer and non-spin-transfer channels were deduced separately by tagging the decay by γ emission from the ^{12}C ejectile. Besides the well-known Gamow-Teller and isobaric analog transitions, a clear signature of the IVSMR was identified. By comparing with the results from light-ion reactions on the same target nucleus and theoretical predictions, the suitability of this new probe for studying the IVSMR was confirmed.

Published
2018

33. Note: An innovative method for

Author

Hideshi, Muto, Yukimitsu, Ohshiro, Yasuteru, Kotaka, Hidetoshi, Yamaguchi, Yasuhiro, Sakemi, Kiyoshi, Kobayashi, Makoto, Nishimura, Michihiro, Oyaizu, Shigeru, Kubono, Masayuki, Kase, Toshiyuki, Hattori, and Susumu, Shimoura

Abstract

It is a major and complex task to accelerate an ion which has the same charge to mass ratio with strong contaminant ions, such as

Published
2018

34. Exclusive quasi-free proton knockout from oxygen isotopes at intermediate energies

Author

Kazuyuki Ogata, Shinsuke Ota, T. Fukunaga, Juzo Zenihiro, C. S. Lee, S. S. Stepanyan, T. Suzuki, Masaki Sasano, Takashi Wakui, Masanori Dozono, Elizabeth Padilla-Rodal, N. Inabe, Hiroshi Tokieda, Motonobu Takaki, Yukie Maeda, Naoki Fukuda, A. Galindo-Uribarri, W. Kim, Kensuke Kusaka, Kazuki Yoshida, Atsushi Tamii, Tomotsugu Wakasa, Rin Yokoyama, Yoshiyuki Yanagisawa, Hiroyuki Takeda, Tetsuo Noro, Satoshi Sakaguchi, Y. Nozawa, T. L. Tang, Koichi Yoshida, Shin'ichiro Michimasa, Didier Beaumel, J. Yasuda, Alexandre Obertelli, Hiroaki Matsubara, Hiroshi Suzuki, Motoki Kobayashi, K. Kisamori, T. Kawahara, Kentaro Yako, Toshiyuki Kubo, Hiroyuki Miya, Takahiro Kawabata, Yuki Kubota, T. Fujii, Shoichiro Kawase, Tomohiro Uesaka, Hideyuki Sakai, Susumu Shimoura, Sanghoon Hwang, 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, 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, D13 Stable and unstable nuclei, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, D27 Reactions induced by unstable nuclei, Impulse (physics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Isotopes of oxygen, 13. Climate action, Ab initio quantum chemistry methods, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

International audience; The dependence of the single-particle strength on the difference between proton and neutron separation energies is studied for oxygen isotopes in a wide range of isospins. The cross sections of the quasi-free (p, 2p) reaction on 14,16,18,22,24O were measured at intermediate energies. The measured cross sections are compared to predictions based on the distorted wave impulse approximation and shell-model psd valence-space spectroscopic factors. The reduction factors, which are the ratio of the experimental cross sections to the theoretical predictions, show no apparent dependence on the proton–neutron separation energy difference. The result is compatible with the result of the (e, e p) reaction on stable targets and with the predictions of recent ab initio calculations.

Published
2018

35. Low-lying dipole response in the unstable Ni70 nucleus

Author

A. Giaz, P. Doornenbal, F. C. L. Crespi, Takashi Nakamura, Ryo Taniuchi, C. Caesar, Hua-Lei Wang, Noritsugu Nakatsuka, S. Ceruti, R. Avigo, F. Camera, Naoki Fukuda, Shoko Koyama, H. Baba, Hideaki Otsu, O. Wieland, David Steppenbeck, Atsumi Saito, H. Scheit, J. Tsubota, Satoshi Takeuchi, K. Yoneda, S. R. Banerjee, Masafumi Matsushita, Yoshiaki Shiga, T. Ozaki, B. Million, Toshiyuki Sumikama, Thomas Aumann, Susumu Shimoura, Yosuke Kondo, A. Bracco, G. Benzoni, Hiroyoshi Sakurai, T. Motobayashi, Kazuo Ieki, M. Shikata, V. Derya, J. Tscheuschner, T. Kubo, Masanori Nishimura, Yasuhiro Togano, K. Boretzky, F. Schindler, Kathrin Wimmer, Nagao Kobayashi, P. Schrock, and Si-Ge Chen

Subjects
Physics, Dipole, medicine.anatomical_structure, 010308 nuclear & particles physics, 0103 physical sciences, medicine, Atomic physics, 010306 general physics, 01 natural sciences, Nucleus, Lying
Published
2018

36. Different mechanism of two-proton emission from proton-rich nuclei 23Al and 22Mg

Author

Kazuyoshi Kurita, H. Kimura, Satoshi Takeuchi, Min Wang, P. Zhou, Y. Hara, D. Q. Fang, Takeo Kawabata, K. Okada, Hiroyoshi Sakurai, E. Takeshita, T. Motobayashi, H. Baba, Z. G. Hu, T. Honda, S. Kanno, R. Shioda, Shuichi Ota, X. Z. Cai, Kazuo Ieki, A. Ozawa, J. G. Chen, Y. Yasuda, H. Ooishi, Yasuhiro Togano, Kenichiro Yoneda, Guoqiang Zhang, Wendong Tian, Y. Ito, Y. Fu, Susumu Shimoura, W. Guo, H. Murakami, Meiko Kurokawa, Xi-Guang Cao, XY Sun, Tetsuaki Moriguchi, Naohito Iwasa, Jian-Song Wang, Yoko Ishibashi, Yosuke Kondo, Nori Aoi, Yu-Gang Ma, Y. Yamada, H. W. Wang, and K. Yamada

Subjects
Physics, Nuclear and High Energy Physics, Nuclear Theory, Proton, FOS: Physical sciences, lcsh:QC1-999, Nuclear Theory (nucl-th), Momentum, Excited state, Physics::Accelerator Physics, Nuclear Experiment (nucl-ex), Proton emission, Atomic physics, Nuclear Experiment, Nuclear theory, Beam (structure), lcsh:Physics
Abstract

Two-proton relative momentum ($q_{pp}$) and opening angle ($\theta_{pp}$) distributions from the three-body decay of two excited proton-rich nuclei, namely $^{23}$Al $\rightarrow$ p + p + $^{21}$Na and $^{22}$Mg $\rightarrow$ p + p + $^{20}$Ne, have been measured with the projectile fragment separator (RIPS) at the RIKEN RI Beam Factory. An evident peak at $q_{pp}\sim20$ MeV/c as well as a peak in $\theta_{pp}$ around 30$^\circ$ are seen in the two-proton break-up channel from a highly-excited $^{22}$Mg. In contrast, such peaks are absent for the $^{23}$Al case. It is concluded that the two-proton emission mechanism of excited $^{22}$Mg is quite different from the $^{23}$Al case, with the former having a favorable diproton emission component at a highly excited state and the latter dominated by the sequential decay process.

Published
2015
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37. Time-stamping system for nuclear physics experiments at RIKEN RIBF

Author

Susumu Shimoura, Y. X. Watanabe, Hidetada Baba, Tsuyoshi Ohnishi, Satoshi Takeuchi, K. Yoshinaga, Shuichi Ota, K. Yoshida, and Takashi Ichihara

Subjects
Physics, Nuclear and High Energy Physics, business.industry, Monte Carlo method, Detector, Dead time, Coincidence, Nuclear physics, Data acquisition, Software, Factory (object-oriented programming), Timestamp, business, Instrumentation
Abstract

A time-stamping system for nuclear physics experiments has been introduced at the RIKEN Radioactive Isotope Beam Factory. Individual trigger signals can be applied for separate data acquisition (DAQ) systems. After the measurements are complete, separately taken data are merged based on the time-stamp information. In a typical experiment, coincidence trigger signals are formed from multiple detectors to take desired events only. The time-stamping system allows the use of minimum bias triggers. Since coincidence conditions are given by software, a variety of physics events can be flexibly identified. The live time for a DAQ system is important when attempting to determine reaction cross-sections. However, the combined live time for separate DAQ systems is not clearly known because it depends not only on the DAQ dead time but also on the coincidence conditions. Using the proposed time-stamping system, all trigger timings can be acquired, so that the combined live time can be easily determined. The combined live time is also estimated using Monte Carlo simulations, and the results are compared with the directly measured values in order to assess the accuracy of the simulation.

Published
2015

38. Status of Plasma Spectroscopy Method for CNS Hyper-ECR Ion Source at RIKEN

Author

Michihiro Oyaizu, Shigeru Kubono, Masayuki Kase, Toshiyuki Hattori, Hideshi Muto, Shinichi Watanabe, Yukimitsu Ohshiro, Shoichi Yamaka, H. Yamaguchi, and Susumu Shimoura

Subjects
ECR plasma, Materials science, Beam selection, Ion beam, Mass-to-charge ratio, Plasma, Physics and Astronomy(all), Ion gun, Ion source, law.invention, Ion, Same q/m, Ion beam deposition, Physics::Plasma Physics, law, Physics::Accelerator Physics, Grating monochromator, Atomic physics, Monochromator
Abstract

The optical line spectra of multi-charged gaseous and metal ion beams from ECR plasma have been observed using a grating monochromator with photomultiplier. This new method simplifies the observation of the targeted ion species in the plasma during beam tuning. In this paper we describe present condition of the Hyper-ECR ion source tuning with this plasma spectroscopy method. This data is important because separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is almost impossible.

Published
2015
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39. Neutron occupancy of the 0d5/2 orbital and the N=16 shell closure in 24O

Author

Y. Kawada, Y. Nakayama, Dóra Sohler, H. Bhang, N. A. Orr, Carlos A. Bertulani, T. Zheng, K. Tshoo, F. Delaunay, Masafumi Matsushita, Satoshi Takeuchi, Jongwon Hwang, Kenichiro Yoneda, N. Tanaka, T. Honda, T. Kobayashi, S. Deguchi, N. Kobayashi, Z X Cao, Takashi Nakamura, Susumu Shimoura, Hideaki Otsu, Nori Aoi, S. Choi, J. Gibelin, Tohru Motobayashi, Kanenobu Tanaka, Yasuhiro Togano, Hiroyoshi Sakurai, F M Marques, K. Yoshinaga, Z. H. Li, Yosuke Kondo, M. Ishihara, Y. Miyashita, Y. Satou, and Toshiyuki Sumikama

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Impulse (physics), 01 natural sciences, Decay energy, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Beam energy
Abstract

One-neutron knockout from 24O leading to the first excited state in 23O has been measured for a proton target at a beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of 23O was reconstructed from the measured four momenta of the 22O fragment and emitted neutron. A sharp peak was found at E decay = 50 ± 3 keV , corresponding to an excited state in 23O at 2.78 ± 0.11 MeV , as observed in previous measurements. The longitudinal momentum distribution for this state was consistent with d-wave neutron knockout, providing support for a J π assignment of 5 / 2 + . The associated spectroscopic factor was deduced to be C 2 S ( 0 d 5 / 2 ) = 4.1 ± 0.4 by comparing the measured cross section ( σ − 1 n exp = 61 ± 6 mb ) with a distorted wave impulse approximation calculation. Such a large occupancy for the neutron 0 d 5 / 2 orbital is in line with the N = 16 shell closure in 24O.

Published
2014

40. Study of proton- and deuteron-induced spallation reactions on the long-lived fission product 93Zr at 105 MeV/nucleon in inverse kinematics

Author

Satoru Momiyama, Yasushi Watanabe, S. Kawakami, Yosuke Kondo, H. Otsu, Masayuki Aikawa, Teiichiro Matsuzaki, Shoichiro Kawase, T. Ozaki, Meiko Uesaka, Yukie Maeda, Masafumi Matsushita, Hiroyoshi Sakurai, Pieter Doornenbal, Satoshi Takeuchi, Shouhei Araki, Megumi Niikura, Shin'ichiro Michimasa, Sidong Chen, Takashi Nakamura, P. A. Söderström, J. Tsubota, Yoshiaki Shiga, Toshiyuki Sumikama, Hiroshi Suzuki, Shigeru Kubono, D. S. Ahn, Hiroyuki Takeda, Tatsuya Yamamoto, M. Shikata, Kathrin Wimmer, Koichi Yoshida, A. Makinaga, Susumu Shimoura, Tadahiro Kin, Yukinobu Watanabe, Tadaaki Isobe, Takashi Ando, Nobuyuki Chiga, Yasuhiro Togano, Hongwei Wang, Atsumi Saito, Naoki Fukuda, Keita Nakano, Shunpei Koyama, S. Nagamine, Ryo Taniuchi, Takeshi Saito, and Yohei Shimizu

Subjects
Nuclear physics, Physics, Inverse kinematics, Deuterium, Proton, 010308 nuclear & particles physics, 0103 physical sciences, General Physics and Astronomy, Spallation, 010306 general physics, Nucleon, Long-lived fission product, 01 natural sciences
Published
2017

41. Spallation reaction study for the long-lived fission product 107Pd

Author

Masayuki Aikawa, Tatsuya Yamamoto, Keita Nakano, Takashi Nakamura, Masafumi Matsushita, Hiroshi Suzuki, Atsumi Saito, Susumu Shimoura, Tadahiro Kin, Shunpei Koyama, H. Otsu, Pär-Anders Söderström, S. Nagamine, S. Kawakami, Takeshi Saito, T. Ozaki, Meiko Uesaka, Satoru Momiyama, Tadaaki Isobe, Yoshiaki Shiga, Yosuke Kondo, Toshiyuki Sumikama, Megumi Niikura, Takashi Ando, Shigeru Kubono, Chiga Nobuyuki, Yasuhiro Togano, Shoichiro Kawase, Koichi Yoshida, Yohei Shimizu, Yukinobu Watanabe, Satoshi Takeuchi, Yukie Maeda, Shin'ichiro Michimasa, Pieter Doornenbal, Hongwei Wang, R. Taniuchi, J. Tsubota, Hiroyuki Takeda, Sidong Chen, Hiroyoshi Sakurai, Kathrin Wimmer, Yasushi Watanabe, A. Makinaga, M. Shikata, Shouhei Araki, Teiichiro Matsuzaki, Naoki Fukuda, and DeukSoon Ahn

Subjects
Physics, Nuclear physics, 010308 nuclear & particles physics, 0103 physical sciences, General Physics and Astronomy, Spallation, Fission product yield, 010306 general physics, Long-lived fission product, 01 natural sciences
Published
2017

42. Cross sections for nuclide production in proton- and deuteron-induced reactions on93Nb measured using the inverse kinematics method

Author

S. Kawakami, Shunpei Koyama, Keita Nakano, S. Nagamine, Hongwei Wang, J. Tsubota, Kathrin Wimmer, Sidong Chen, Naoki Fukuda, Megumi Niikura, Toshiyuki Sumikama, Ryo Taniuchi, Takeshi Saito, Teiichiro Matsuzaki, Koichi Yoshida, Shigeru Kubono, Takashi Ichihara, P. A. Söderström, Yohei Shimizu, Pieter Doornenbal, Nobuyuki Chiga, Atsumi Saito, D. S. Ahn, Yasushi Watanabe, Satoshi Takeuchi, Meiko Kurokawa, Shouhei Araki, Shin'ichiro Michimasa, Susumu Shimoura, Tadahiro Kin, Toshiyuki Kubo, Tadaaki Isobe, Yasuhiro Togano, Takashi Nakamura, Masafumi Matsushita, Hiroyuki Takeda, T. Ozaki, Tatsuya Yamamoto, Yukie Maeda, Masayuki Aikawa, M. Shikata, Hiroyoshi Sakurai, A. Makinaga, Satoru Momiyama, Yosuke Kondo, Shoichiro Kawase, Hideaki Otsu, Hiroshi Suzuki, Yoshiaki Shiga, and Yukinobu Watanabe

Subjects
Range (particle radiation), Inverse kinematics, Proton, 010308 nuclear & particles physics, Chemistry, Physics, QC1-999, Nuclear Theory, Evaporation, 01 natural sciences, Nuclear physics, Deuterium, Cascade, 0103 physical sciences, Physics::Accelerator Physics, Nuclide, Atomic physics, Nuclear Experiment, 010306 general physics, Beam (structure)
Abstract

Isotopic production cross sections were measured for proton- and deuteron-induced reactions on 93 Nb by means of the inverse kinematics method at RIKEN Radioactive Isotope Beam Factory. The measured production cross sections of residual nuclei in the reaction 93 Nb + p at 113 MeV/u were compared with previous data measured by the conventional activation method in the proton energy range between 46 and 249 MeV. The present inverse kinematics data of four reaction products (90 Mo, 90 Nb, 88 Y, and 86 Y) were in good agreement with the data of activation measurement. Also, the model calculations with PHITS describing the intra-nuclear cascade and evaporation processes generally well reproduced the measured isotopic production cross sections.

Published
2017

43. Development of low-pressure multi-wire drift chambers for high-resolution spectroscopy with radioactive isotope beams

Author

Shuichi Ota, Tomohiro Uesaka, Yuki Kubota, K. Miki, Shoichiro Kawase, Hiroaki Matsubara, Hiroyuki Miya, T. Fujii, Shin'ichiro Michimasa, A. Saito, Hideyuki Sakai, Susumu Shimoura, and C. S. Lee

Subjects
Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Scattering, business.industry, Chemistry, Detector, Tracking (particle physics), Nuclear physics, Optics, Physics::Accelerator Physics, Atomic number, Nuclear Experiment, Nucleon, Spectroscopy, business, Instrumentation, Beam (structure), Voltage
Abstract

Low-pressure multi-wire drift chambers have been developed to track high-intensity radioactive isotope beams at the energies of around 200 MeV/nucleon. In order to minimize the effect of multiple scattering by radioactive isotope beam, the thickness of the detectors were minimized by using isobutane gas at low pressure (10 kPa). The performance of the position resolution, the tracking efficiency, and the beam intensity capability were evaluated as a function of atomic number and applied voltage. As a result, an overall position resolution of 300 μm was achieved for radioactive isotope beams with an intensity of 1 MHz. The details of the design specifications and performances of the low-pressure multi-wire drift chambers are described.

Published
2013

44. Development of CVD diamond detector for time-of-flight measurements

Author

Tomohiro Uesaka, Hideyuki Sakai, Susumu Shimoura, Shuichi Ota, Remco Zegers, T. L. Tang, Andreas Stolz, S. Michimasa, Hiroaki Matsubara, Masanori Dozono, Hiroyuki Miya, Eiji Ideguchi, Shintaro Go, Motonobu Takaki, K. Kisamori, Hiroshi Tokieda, and H. Baba

Subjects
Nuclear and High Energy Physics, Optical fiber, Materials science, business.industry, Detector, Analytical chemistry, Chemical vapor deposition, Signal, Particle detector, law.invention, Time of flight, Optics, law, business, Instrumentation, Radiation hardening, Jitter
Abstract

The paper describes recent developments of diamond detector at CNS and discusses the timing signal transfer system suitable for optimizing its performance. The diamond detector is well known to have good properties as a radiation detector such as fast response and good radiation hardness. Consequently, it is an excellent candidate for serving as a high-resolution thin timing detector. CNS and NSCL/MSU started a collaboration to develop diamond detectors, and manufactured a detector with a size of 28 × 28 mm2 and thickness of 200 μm. An irradiation experiment of the detector was performed by using a 32-MeV α beam to check its basic performance. The CNS detector had almost 100% efficiency and a timing resolution of 27 ps ( σ ). Jitter in long optical-fiber signal-transfer lines was examined and found to be 10.7 ps ( σ ). Diamond detectors and signal transfer system using a optical fiber enable us to provide time-of-flight measurements with extremely high resolution.

Published
2013

45. SHARAQ spectrometer for high-resolution studies for RI-induced reactions

Author

Hiromi Sato, C. S. Lee, Yuki Kubota, K. Miki, S. Ota, Y. Yanagisawa, Toshiyuki Kubo, Shoichiro Kawase, Hiroshi Suzuki, T. Uesaka, Naoki Fukuda, T. Fujii, T. Baba, Naohito Inabe, Masanori Dozono, Hiroyuki Takeda, Susumu Shimoura, Shumpei Noji, Andreas Stolz, Y. Kikuchi, Takeo Kawabata, Shin'ichiro Michimasa, T. Ichihara, Hiroaki Matsubara, Remco Zegers, Hiroyuki Miya, H. Baba, Hideyuki Sakai, Yuji Shimizu, Kentaro Yako, Motoki Kobayashi, Hiroshi Tokieda, Daisuke Kameda, Rin Yokoyama, Yoshiko Sasamoto, Takahiro Nishi, K. Kisamori, Motonobu Takaki, M. Tsumura, and Shintaro Go

Subjects
Nuclear and High Energy Physics, Spectrometer, Physics::Instrumentation and Detectors, Chemistry, business.industry, Resolution (electron density), Detector, Tracking (particle physics), law.invention, Nuclear physics, Momentum, Optics, Beamline, Achromatic lens, law, Physics::Accelerator Physics, business, Instrumentation, Beam (structure)
Abstract

The SHARAQ spectrometer and High-Resolution Beamline, which began operation in March 2009, have been put into use for six experiments using charge exchange reactions with radioactive isotope beams. For experiments at SHARAQ, detector developments and ion optics studies continue to improve performance in high-resolution nuclear spectroscopy. We have introduced improved timing resolution with CVD diamond detectors, high count-rate beamline tracking detectors and development of multi-particle detection by cathode-readout drift chambers. Ion-optics studies for the high-resolution achromatic (HA) and dispersion-matching (DM) transport modes are also reported here. Momentum tagging in the HA mode demonstrated an improvement in spectroscopic resolution with respect to the momentum spread of the radioactive beam. For the DM transportation mode, a momentum resolution of 1 / 8100 (FWHM) was achieved by taking into account the positions and angles of the beam at the third focal plane of BigRIPS.

Published
2013

46. 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

47. Current Status of Plasma Spectroscopic Experiments with Hyper-ECR Ion Source at CNS, University of Tokyo.

Author

Hideshi Muto, Yukimitsu Ohshiro, Yasuteru Kotaka, Yasuhiro Sakemi, Hidetoshi Yamaguchi, Kiyoshi Kobayashi, Makoto Nishimura, Masayuki Kase, Michihiro Oyaizu, Shigeru Kubono, Toshiyuki Hattori, and Susumu Shimoura

Subjects
ION sources, PLASMA currents, PLASMA spectroscopy, PLASMA production, METAL ions, ELECTRON cyclotron resonance sources, PLASMA beam injection heating, LIGHT intensity
Abstract

During operations of the Hyper-ECR ion source at the Center for Nuclear Study, University of Tokyo, an observation of plasma light intensities by a monochromator was made. Various gaseous and metal ions are produced, then extracted, and injected into RIKEN AVF cyclotron by the Hyper-ECR ion source. In this study, we developed the method of determining the crucible position, the magnetic strength distribution, and the RF power necessary for the plasma production. In summary, this study proves the importance of plasma spectroscopy for ion source operation. [ABSTRACT FROM AUTHOR]

Published
2019
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48. Invariant Mass Spectroscopy of 23O via the (p, p′) Reaction in Inverse Kinematics

Author

Hiroyoshi Sakurai, F. Delaunay, Y. Nakayama, T. Zheng, Satoshi Takeuchi, T. Honda, N. A. Orr, Y. Satou, Dóra Sohler, N. Kobayashi, H. Bhang, Kanenobu Tanaka, Hideaki Otsu, Y. Miyashita, Masafumi Matsushita, Y. Kawada, S. Choi, F M Marques, Yosuke Kondo, K. Yoshinaga, Jongwon Hwang, M. Ishihara, J. Gibelin, T. Kobayashi, Tohru Motobayashi, K. Tshoo, Z X Cao, Yasuhiro Togano, S. Deguchi, T. Sumikama, Z. H. Li, Takashi Nakamura, Kenichiro Yoneda, Susumu Shimoura, N. Tanaka, Nori Aoi, 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), and Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics, Inverse kinematics, Proton, 010308 nuclear & particles physics, Nuclear Theory, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Resonance (particle physics), Atomic and Molecular Physics, and Optics, 0103 physical sciences, Invariant mass, Neutron, Atomic physics, 010306 general physics, Nucleon, Spectroscopy, Nuclear Experiment
Abstract

The neutron-rich oxygen isotope O-23 has been investigated via proton inelastic scattering on a liquid hydrogen target at 63.5 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum. A sharp resonance state was observed at 42(5) keV above the neutron threshold. A comparison of the differential cross section leading to this state with a microscopic DWBA calculation allowed a J (pi) assignment of 5/2(+) for this state.

Published
2013

49. Discovery of the First 2- State in 16C via Neutron Knockout Reaction

Author

Takashi Nakamura, Hideaki Otsu, Jongwon Hwang, Masamichi Ishihara, Hooi Jin Ong, T. Nakabayashi, Susumu Shimoura, M. Tamaki, Y. Hashimoto, Toshio Kobayashi, Yasuhiro Togano, N. Matsui, T. Okumura, M. Kitayama, Y. Satou, Tomoko Gomi, Nori Aoi, S. Kawai, Yosuke Kondo, Yasuhiro H. Matsuda, Y. Yanagisawa, Satoshi Takeuchi, M. Shinohara, Hiroyoshi Sakurai, T. Motobayashi, N. Endo, Takashi Sugimoto, N. Fukuda, and T. K. Onishi

Subjects
Physics, Nuclear Theory, Atomic and Molecular Physics, and Optics, Coincidence, Nuclear physics, Cross section (physics), medicine.anatomical_structure, medicine, Neutron, Invariant mass, Atomic physics, Nuclear Experiment, Spectroscopy, Nucleus, Excitation, Liquid hydrogen
Abstract

The 16C nucleus has been investigated by the neutron knockout reaction of 17C on a liquid hydrogen target. Applying the invariant mass method in inverse kinematics and γ-ray spectroscopy, the energy spectrum was reconstructed by triple-coincidence measurement, in which neutrons, charged fragments, and γ rays from the decay of the reaction residue (16C*) were detected. A peak at 0.47 MeV was observed in the invariant mass spectrum in coincidence with a peak at 0.74 MeV in the γ-ray spectrum, which indicates the presence of an unbound state with an excitation energy of 5.46 MeV. Comparison of the experimental cross section with the value derived by a theoretical calculation provided evidence that the spin-parity of this state is 2−.

Published
2013

50. Spectroscopic Measurement in 9He and 12Be

Author

Kichiji Hatanaka, Susumu Shimoura, Y. Kikuch, T. Hashimoto, Takayoshi Suzuki, Nori Aoi, Satoshi Sakaguchi, Hiroyuki Miya, H. C. Lee, Shumpei Noji, Yusuke T. Maeda, Motonobu Takaki, Juzo Zenihiro, T. Fujii, Takeo Kawabata, Yuusuke Yasuda, Kentaro Yako, Tomohiro Uesaka, N. Yokota, Shuichi Ota, K. Kisamori, C. S. Lee, Yuki Kubota, Yoshiko Sasamoto, L. T. Tang, K. Miki, Masanori Dozono, Shoichiro Kawase, Hiroshi Matsubara, Keiji Takahisa, Hiroshi Tokieda, Rin Yokoyama, Shin'ichiro Michimasa, and Atsushi Tamii

Subjects
Physics, Cross section (physics), Nuclear Theory, Neutron, Atomic physics, Nuclear Experiment, Spectroscopy, Atomic and Molecular Physics, and Optics, Energy (signal processing), Excitation, Charge exchange
Abstract

Spectroscopy for neutron-rich nuclei 9He and 12Be has been performed by means of heavy-ion double charge exchange (HIDCX) (18O, 18Ne) reaction on stable target nuclei 9Be and 12C, respectively. Several clear peaks in 12Be at low excitation energy region even above neutron separation energy have been observed in one-shot measurement, whereas no prominent signals of 9He have been observed owing to the small cross section. It is shown that the HIDCX reaction is a new powerful spectroscopic tool for study of unstable neutron-rich nuclei.

Published
2013

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