307 results on '"Tomohiro Uesaka"'
Search Results
2. Dynamic Electron Polarization Lasting More Than 10 μs by Hybridizing Porphyrin and TEMPO with Flexible Linkers
- Author
-
Koki Nishimura, Reiya Yabuki, Tomoyuki Hamachi, Nobuo Kimizuka, Kenichiro Tateishi, Tomohiro Uesaka, and Nobuhiro Yanai
- Subjects
Materials Chemistry ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films - Published
- 2023
3. Polarizing agents beyond pentacene for efficient triplet dynamic nuclear polarization in glass matrices.
- Author
-
Keita Sakamoto, Tomoyuki Hamachi, Katsuki Miyokawa, Kenichiro Tateishi, Tomohiro Uesaka, Yuki Kurashige, and Nobuhiro Yanai
- Subjects
POLARIZATION (Nuclear physics) ,PENTACENE ,ELECTRON paramagnetic resonance ,ELECTRON distribution ,SPIN polarization - Abstract
Triplet dynamic nuclear polarization (triplet-DNP) is a technique that can obtain high nuclear polarization under moderate conditions. However, in order to obtain practically useful polarization, large single crystals doped with a polarizing agent must be strictly oriented with respect to the magnetic field to sharpen the electron spin resonance (ESR) spectra, which is a fatal problem that prevents its application to truly useful biomolecular targets. Instead of this conventional physical approach of controlling crystal orientation, here, we propose a chemical approach, i.e., molecular design of polarizing agents; pentacene molecules, the most typical triplet-DNP polarizing agent, are modified so as to make the triplet electron distribution wider and more isotropic without loss of the triplet polarization. The thiophene-modified pentacene exhibits a sharper and stronger ESR spectrum than the parent pentacene, and state-of-the-art quantum chemical calculations revealed that the direction of the spin polarization is altered by the modification with thiophene moieties and the size of D and E parameters are reduced from parent pentacene due to the partial delocalization of spin densities on the thiophene moieties. The triplet-DNP with the new polarizing agent successfully exceeds the previous highest ¹H polarization of glassy materials by a factor of 5. This demonstrates the feasibility of a polarizing agent that can surpass pentacene, the best polarizing agent for more than 30 y since triplet-DNP was first reported, in the unoriented state. This work provides a pathway toward practically useful high nuclear polarization of various biomolecules by triplet-DNP. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Spin-Polarized Radicals with Extremely Long Spin-Lattice Relaxation Time at Room Temperature in a Metal-Organic Framework
- Author
-
Kana Orihashi, Akio Yamauchi, Saiya Fujiwara, Mizue Asada, Toshikazu Nakamura, Joseph Ka-Ho Hui, Nobuo Kimizuka, Kenichiro Tateishi, Tomohiro Uesaka, and Nobuhiro Yanai
- Abstract
The generation of spin polarization is key in quantum information science and dynamical nuclear polarization. Polarized electron spins with long spin-lattice relaxation times (T1) at room temperature are important for these applications, but have been difficult to achieve. We report the realization of spin-polarized radicals with extremely long T1 at room temperature in a metal-organic framework (MOF) in which azaacene chromophores are densely integrated. Persistent radicals are generated in the MOF by charge separation after photoexcitation. Spin polarization of triplet generated by photoexcitation are successfully transferred to the persistent radicals. Pulse ESR measurements reveal that the T1 of the polarized radical in the MOF is as long as 274 s at room temperature. The achievement of extremely long spin polarization in MOFs with nanopores accessible to guest molecules will be an important cornerstone for future highly sensitive quantum sensing and efficient dynamic nuclear polarization.
- Published
- 2023
5. Triplet Dynamic Nuclear Polarization of Pyruvate via Supramolecular Chemistry
- Author
-
Tomoyuki Hamachi, Koki Nishimura, Keita Sakamoto, Yusuke Kawashima, Hironori Kouno, Shunsuke Sato, Go Watanabe, Kenichiro Tateishi, Tomohiro Uesaka, and Nobuhiro Yanai
- Abstract
Dynamic nuclear polarization (DNP) significantly improves the sensitivity of magnetic resonance imaging, and its most important medical application is cancer diagnosis via hyperpolarized 13C-labeled pyruvate. Unlike cryogenic DNP, triplet-DNP uses photoexcited triplet electrons under mild conditions. However, triplet-DNP of pyruvate has not been observed because of incompatibility of the hydrophobic polarizing agent with hydrophilic pyruvate. This work demonstrates that supramolecular complexation with β-cyclodextrin can disperse 4,4′-(pentacene-6,13-diyl)dibenzoate (NaPDBA), a pentacene derivative with hydrophilic substituents, even in the presence of high sodium pyruvate concentrations. The polarization of photoexcited triplet electron spins in NaPDBA was transferred to the 13C spins of sodium pyruvate via triplet-DNP of 1H spins in water and 1H-to-13C cross-polarization. This provides an important step toward the widespread use of ultra-sensitive MRI for cancer diagnosis.
- Published
- 2023
6. Development of a Polarized Proton Target for Spin-correlation Coefficient Measurements
- Author
-
Atomu Watanabe, Yuko Saito, Kimiko Sekiguchi, Kenichiro Tateishi, Sho Kitayama, Yoshiki Maruta, Takaya Matsui, Kenjiro Miki, Hiroo Umetsu, Ren Urayama, and Tomohiro Uesaka
- Published
- 2022
7. Latest results concerning short range correlations obtained in the dp elastic and dp breakup processes at Nuclotron, JINR
- Author
-
Marian Janek, Vladimir P. Ladygin, Alexander V. Averyanov, Eugene V. Chernykh, Dan D. Enache, Yuri V. Gurchin, Alexandr Yu. Isupov, Julia-Tatiana Karachuk, Anatoly N. Khrenov, Dimitry O. Krivenkov, Pavel K. Kurilkin, Nadezhda B. Ladygina, Alexei N. Livanov, Olena Mezhenska, Semen M. Piyadin, Sergei G. Reznikov, Yaroslav T. Skhomenko, Arkady A. Terekhin, Alexei V. Tishevsky, Tomohiro Uesaka
- Subjects
Physics ,QC1-999 - Abstract
Deuteron spin structure program is aimed on extraction of two and three nucleon forces information, including their spin dependent parts, from dp elastic and dp breakup processes investigated at intermediate energies. The dp elastic data were obtained at Internal Target Station of Nuclotron (JINR) in the energy range 400-1800 MeV using polarized deuteron beam. Strong sensitivity to the short range spin structure of the isoscalar nucleon-nucleon correlations is observed in deuteron analyzing powers. Preliminary results of the the cross section for the dp breakup reaction have been obtained at 400 MeV of deuteron energy.
- Published
- 2020
- Full Text
- View/download PDF
8. Design Guidelines to Elongate Spin–Lattice Relaxation Times of Porphyrins with Large Triplet Electron Polarization
- Author
-
Yoichi Sasaki, Nobuo Kimizuka, Nobuhiro Yanai, Kenichiro Tateishi, Tomohiro Uesaka, Fujiwara Saiya, Koki Nishimura, and Akio Yamauchi
- Subjects
010304 chemical physics ,Spin–lattice relaxation ,Light irradiation ,chemistry.chemical_element ,Electron ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Porphyrin ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Fluorine ,Physical and Theoretical Chemistry ,Triplet state ,Spin density ,Polarization (electrochemistry) - Abstract
The spin-polarized triplet state generated by light irradiation has potential for applications such as triplet dynamic nuclear polarization (triplet-DNP). Recently, we have reported free-base porphyrins as versatile and biocompatible polarizing agents for triplet-DNP. However, the electron polarization of free-base porphyrins is not very high, and the dilemma is that the high polarization of metalloporphyrins is accompanied by a too short spin-lattice relaxation time to be used for triplet-DNP. We report here that the introduction of electron-withdrawing fluorine groups into Zn porphyrins enables a long enough spin-lattice relaxation time (>1 μs) while maintaining a high polarization (Px:Py:Pz = 0:0:1.0) at room temperature. Interestingly, the spin-lattice relaxation time of Zn porphyrin becomes much longer by introducing fluorine substituents, whereas the spin-lattice relaxation time of free-base porphyrin becomes shorter by the fluorine substitution. Theoretical calculations suggest that this is because the introduction of the electron-withdrawing fluorine substituents reduces the spin density on Zn atoms and weakens the spin-orbit interaction.
- Published
- 2021
9. Singlet fission as a polarized spin generator for biological nuclear hyperpolarization
- Author
-
Yusuke Kawashima, Tomoyuki Hamachi, Akio Yamauchi, Koki Nishimura, Yuma Nakashima, Saiya Fujiwara, Nobuo Kimizuka, Tomohiro Ryu, Tetsu Tamura, Masaki Saigo, Ken Onda, Shunsuke Sato, Yasuhiro Kobori, Kenichiro Tateishi, Tomohiro Uesaka, Go Watanabe, Kiyoshi Miyata, and Nobuhiro Yanai
- Subjects
Condensed Matter::Strongly Correlated Electrons - Abstract
Singlet fission (SF), converting a singlet excited state into a spin-correlated triplet-pair state, is the sole way to generate a spin quintet state in organic materials. Although its application to photovoltaics as an exciton multiplier has been extensively studied, use of its unique spin degree of freedom is largely unexplored. Here, we demonstrate that the spin polarization of the quintet multiexcitons generated by SF improves the sensitivity of biological magnetic resonance through dynamic nuclear polarization (DNP). We form supramolecular assemblies of a few pentacene chromophores and use SF-born quintet spins to achieve DNP of water-glycerol, the most basic biological matrix, at lower microwave intensities than for conventional triplet-based DNP. Our demonstration opens a new use of SF as a “polarized spin generator” in bio-quantum technology.
- Published
- 2022
10. Porphyrins as Versatile, Aggregation-Tolerant, and Biocompatible Polarizing Agents for Triplet Dynamic Nuclear Polarization of Biomolecules
- Author
-
Tomoyuki Hamachi, Yusuke Kawashima, Nobuo Kimizuka, Tomohiro Uesaka, Hironori Kouno, Nobuhiro Yanai, Koki Nishimura, and Kenichiro Tateishi
- Subjects
chemistry.chemical_classification ,Magnetic Resonance Spectroscopy ,Porphyrins ,Materials science ,Molecular Structure ,Spin polarization ,Biomolecule ,Physics::Medical Physics ,Biocompatible Materials ,Electron ,Biocompatible material ,Porphyrin ,Sodium salt ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Chemical physics ,General Materials Science ,Physical and Theoretical Chemistry ,Polarization (electrochemistry) - Abstract
Triplet dynamic nuclear polarization (triplet-DNP) achieves nuclear spin polarization at moderate temperatures by using spin polarization of photoexcited triplet electrons. The applications of triplet-DNP for biomolecules have been hampered because acenes, the only polarizing agents used so far, tend to aggregate and lose their polarization in biomolecular matrices. Here, we report for the first time use of porphyrins as polarizing agents of triplet-DNP and propose a new concept of aggregation-tolerant polarizing agents. Sodium salts of tetrakis(4-carboxyphenyl)porphyrin (TCPPNa) can be dispersed in amorphous as well as crystalline biomolecular matrices, and importantly, it can generate polarized triplet electrons even in a slightly aggregated state. Triplet-DNP of crystalline erythritol containing slightly aggregated TCPPNa can achieve more than 120-fold signal enhancement. Because TCPPNa is also the first biocompatible triplet-DNP polarizing agent, this work provides a crucial step forward for the biological and medical applications of triplet-DNP.
- Published
- 2021
11. Proton Hyperpolarization Relay from Nanocrystals to Liquid Water
- Author
-
Naoto Matsumoto, Koki Nishimura, Nobuo Kimizuka, Yusuke Nishiyama, Kenichiro Tateishi, Tomohiro Uesaka, and Nobuhiro Yanai
- Subjects
STD-NMR ,Magnetic Resonance Spectroscopy ,Water ,General Chemistry ,NMR data ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Biochemistry ,Catalysis ,Condensed Matter::Materials Science ,Colloid and Surface Chemistry ,Nanoparticles ,DNP ,Condensed Matter::Strongly Correlated Electrons ,Protons ,Microwaves - Abstract
Dynamic nuclear polarization (DNP) using transient electron spin polarization generated by photoexcitation can improve nuclear magnetic resonance (NMR) sensitivity far beyond the thermal equilibrium limit for analysis in life science and drug discovery. However, DNP of liquid water at room temperature remains an important challenge. In previous studies, polarization has been transferred directly from the electron spins in the solid to the nuclear spins of the target, and this has been limited to near-surface solid or highly-viscous targets. Here, we propose a new method called hyperpolarization relay, in which the polarization of electron spins is transferred to proton spins in the nanocrystals and then to proton spins in bulk water by the nuclear Overhauser effect (NOE). Molecular nanocrystals doped with a polarizing agent that generates a highly-polarized photoexcited triplet were synthesized by a reprecipitation method while controlling the size of the nanocrystals. As the size of the nanocrystals decreases, the efficiency of polarization transfer from nanocrystals to water was improved due to the increase in the surface area.
- Published
- 2022
12. 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
13. Triplet dynamic nuclear polarization of crystalline ice using water-soluble polarizing agents
- Author
-
Tomohiro Uesaka, Kana Orihashi, Koki Nishimura, Kenichiro Tateishi, Yusuke Kawashima, Nobuhiro Yanai, Nobuo Kimizuka, and Hironori Kouno
- Subjects
Materials science ,Physics::Medical Physics ,Metals and Alloys ,General Chemistry ,Polarization (waves) ,Catalysis ,Moderate temperature ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Water soluble ,Chemical physics ,Materials Chemistry ,Ceramics and Composites ,Hyperpolarization (physics) ,Physics::Atmospheric and Oceanic Physics - Abstract
Triplet dynamic nuclear polarization (triplet-DNP) allows hyperpolarization at a moderate temperature. While the triplet-DNP of water is strongly desired, water-soluble triplet polarizing agents have not yet been reported. Herein, the first example of triplet-DNP of crystalline ice is demonstrated by molecularly dispersing a novel water-soluble polarizing agent into ice.
- Published
- 2020
14. New ion-optical operating modes of the BigRIPS and ZeroDegree spectrometer for the production and separation of high-quality rare isotopes beams and high-resolution spectrometer experiments
- Author
-
K. Itahashi, Naoki Fukuda, Hans Geissel, Tetsuro Komatsubara, Tomohiro Uesaka, Toshiyuki Kubo, E. Haettner, Kensuke Kusaka, Daichi Murai, Hiroyuki Takeda, Y. Yanagisawa, Masao Ohtake, Toshiyuki Sumikama, Y.K. Tanaka, Takahiro Nishi, Hiroshi Suzuki, Naohito Inabe, S.Y. Matsumoto, Yuji Shimizu, C. Scheidenberger, Bernhard Franczak, Kenichi Yoshida, D. S. Ahn, and Hideki Ueno
- Subjects
Physics ,Nuclear and High Energy Physics ,Spectrometer ,Isotope ,010308 nuclear & particles physics ,Cyclotron ,01 natural sciences ,Ion ,law.invention ,Isotope separation ,Nuclear physics ,Quality (physics) ,law ,Achromatic lens ,0103 physical sciences ,010306 general physics ,Spectroscopy ,Instrumentation - Abstract
BigRIPS is a powerful two-stage in-flight separator for the research with exotic nuclei studied in frontier experiments since more than a decade. The ion-optical system is very versatile due to the multi-stage structure of BigRIPS combined with the ZeroDegree spectrometer or the Superconducting Ring Cyclotron (SRC). Various optical modes can be flexibly realized according to the purpose of experiments. Two categories of developments are presented here. One is a new operating mode of BigRIPS aiming at higher ion-optical resolving power. BigRIPS itself has a two-stage structure. Spatial isotope separation is made at both the first and second stages. In the standard operating mode of BigRIPS, at the second stage the two spatial separations with energy degraders are subtractive in their resolving powers. Here, we present the additive mode. With the resulting increased spatial separation power, the isotopic background can be substantially reduced. Higher ion-optical resolving powers of the first and second BigRIPS degrader stages are also investigated with the goals to reduce further the background and to yield access to new isotopes of heavier elements. The other development is a dispersion-matched system with BigRIPS for high-resolution spectrometer experiments. The BigRIPS and ZeroDegree spectrometer are presently two independent, coupled achromatic systems. A new dispersion-matched mode of BigRIPS and ZeroDegree will enable novel experiments. For high-resolution spectroscopy experiments with high-intensity light projectiles, SRC and BigRIPS can be operated as a dispersion-matched system. The described different ion-optical developments are a base for a new category of experiments exploring exotic nuclei and mesic atoms. Characteristic future experiments with these new ion-optical developments are exemplified in this report.
- Published
- 2020
15. Study of the dp Elastic and dp Breakup Complementary Processes Using Polarized and Unpolarized Beam of Nuclotron
- Author
-
Marian Janek, Vladimir P. Ladygin, Alexander V. Averyanov, Eugene V. Chernykh, Dan D. Enache, Yuri V. Gurchin, Alexandr Yu. Isupov, Julia-Tatiana Karachuk, Anatoly N. Khrenov, Dimitry O. Krivenkov, Pavel K. Kurilkin, Nadezhda B. Ladygina, Alexei N. Livanov, Olena Mezhenska, Semen M. Piyadin, Sergei G. Reznikov, Yaroslav T. Skhomenko, Arkadyi A. Terekhin, Alexei V. Tishevsky, Tomohiro Uesaka, and Ivan S. Volkov
- Subjects
Atomic and Molecular Physics, and Optics - Published
- 2021
16. Triplet Dynamic Nuclear Polarization of Guest Molecules through Induced Fit in a Flexible Metal-Organic Framework
- Author
-
Saiya Fujiwara, Naoto Matsumoto, Koki Nishimura, Nobuo Kimizuka, Kenichiro Tateishi, Tomohiro Uesaka, and Nobuhiro Yanai
- Subjects
General Medicine ,General Chemistry ,Catalysis - Abstract
Dynamic nuclear polarization utilizing photoexcited triplet electrons (triplet-DNP) has great potential for room-temperature hyperpolarization of nuclear spins. However, the polarization transfer to molecules of interest remains a challenge due to the fast spin relaxation and weak interaction with target molecules at room temperature in conventional host materials. Here, we demonstrate the first example of DNP of guest molecules in a porous material at around room temperature by utilizing the induced-fit-type structural transformation of a crystalline yet flexible metal-organic framework (MOF). In contrast to the usual hosts, 1H spin-lattice relaxation time becomes longer by accommodating a pharmaceutical model target 5-fluorouracil as the flexible MOF changes its structure upon guest accommodation to maximize the host-guest interactions. Combined with triplet-DNP and cross-polarization, this system realizes an enhanced 19F-NMR signal of guest target molecules at around room temperature.
- Published
- 2021
17. Investigation of the ground-state spin inversion in the neutron-rich Cl47,49 isotopes
- Author
-
Jason D. Holt, Carlo Barbieri, Zaihong Yang, I. Murray, D. M. Rossi, K. I. Hahn, S. Y. Park, C. Hilaire, Kazuyuki Ogata, C. Lehr, H. Baba, Duo Yan, David Steppenbeck, H. Törnqvist, P. Koseoglou, Masahiro Yasuda, V. Lapoux, Yasuhiro Togano, N. L. Achouri, R.-B. Gerst, Alessandra Corsi, T. Lokotko, B. D. Linh, L. Stuhl, H. Wang, Dóra Sohler, M. Gómez-Ramos, Igor Gašparić, H. N. Liu, Y. L. Sun, Takashi Nakamura, E. Sahin, Petr Navrátil, V. Panin, W. Rodriguez, N. Shimizu, J. M. Gheller, A. Moro, Victor Vaquero, L. X. Chung, Thomas Duguet, K. Moschner, Hiroyoshi Sakurai, Kathrin Wimmer, Dong-Wook Kim, A. Delbart, N. T. Khai, V. Wagner, N. Paul, P. Doornenbal, T. Motobayashi, V. Somà, D. Calvet, T. Isobe, K. Yoneda, O. Aktas, V. Werner, Y. Yamada, Thomas Aumann, F. Flavigny, N. D. Ton, T. Kobayashi, A. Giganon, X. X. Xu, F. Château, Hideaki Otsu, Julien Gibelin, Si-Ge Chen, N. T. T. Phuc, P. A. Söderström, A. Gillibert, Nobuyuki Chiga, A. Obertelli, T. Koiwai, Tomohiro Uesaka, F. Browne, M. MacCormick, Satoshi Takeuchi, M. L. Cortés, Masaki Sasano, S. Franchoo, Yutaka Utsuno, Jenny Lee, Yuya Kubota, L. Zanetti, and Yosuke Kondo
- Subjects
Physics ,Isotope ,010308 nuclear & particles physics ,0103 physical sciences ,Neutron ,Atomic physics ,010306 general physics ,Spin (physics) ,Ground state ,01 natural sciences ,Inversion (discrete mathematics) ,Nuclear theory - Published
- 2021
18. Pairing Forces Govern Population of Doubly Magic Ca54 from Direct Reactions
- Author
-
J. M. Gheller, S. Y. Park, K. Yoneda, Masaki Sasano, P. A. Söderström, D. Sohler, D. Körper, H. Simon, A. Gillibert, K. Miki, Satoshi Takeuchi, Yasuhiro Togano, M. MacCormick, R.-B. Gerst, Duo Yan, Tomohiro Uesaka, Fabia Schindler, V. Wagner, B. D. Linh, M. Holl, A. Corsi, N. Paul, Igor Gašparić, H. N. Liu, P. Koseoglou, E. Sahin, Yosuke Kondo, T. Lokotko, T. Isobe, Victor Vaquero, M. L. Cortés, V. Werner, Takashi Nakamura, W. Rodriguez, Zaihong Yang, A. Delbart, S. Franchoo, F. Château, V. Lapoux, P. Doornenbal, K. I. Hahn, L. Stuhl, I. Murray, C. Caesar, Kazuyuki Ogata, C. Lehr, T. Kobayashi, X. X. Xu, C. Hilaire, Si-Ge Chen, Yutaka Utsuno, V. Panin, A. Giganon, Jenny Lee, N. L. Achouri, L. X. Chung, Y. L. Sun, K. Moschner, Yuya Kubota, D. M. Rossi, H. Baba, F. Flavigny, Masahiro Yasuda, L. Zanetti, Kathrin Wimmer, Dong-Wook Kim, O. Aktas, F. Browne, S. Wang, A. Obertelli, J. Kahlbow, Hiroyoshi Sakurai, T. Motobayashi, Julien Gibelin, K. Boretzky, D. Calvet, David Steppenbeck, H. Törnqvist, Thomas Aumann, Nobuyuki Chiga, T. Koiwai, Kazuki Yoshida, Hideaki Otsu, Hirofumi Yamada, and J. Tscheuschner
- Subjects
Physics ,education.field_of_study ,Proton ,010308 nuclear & particles physics ,Nuclear Theory ,Population ,Nuclear shell model ,General Physics and Astronomy ,01 natural sciences ,7. Clean energy ,Pairing ,Excited state ,0103 physical sciences ,Neutron ,Atomic physics ,Nuclear Experiment ,010306 general physics ,Nucleon ,Ground state ,education - Abstract
Direct proton-knockout reactions of ^{55}Sc at ∼220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of ^{54}Ca were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the ^{55}Sc ground state with states in ^{54}Ca. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of ^{55}Sc, valence proton removals populated predominantly the ground state of ^{54}Ca. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.
- Published
- 2021
19. First Demonstration of Mass Measurements for Exotic Nuclei Using Rare-RI Ring
- Author
-
M. Amano, Ryo Igosawa, Shinsuke Ota, Giuseppe Lorusso, Z. Ge, Yasushi Abe, Yasushige Yano, Kiyoshi Wakayama, Tomohiro Uesaka, Toshio Suzuki, Hidetada Baba, Kunimitsu Nishimuro, Kumi Inomata, Masanori Wakasugi, Sarah Naimi, F. Suzaki, Yoshitaka Yamaguchi, Shunichiro Omika, Daisuke Nagae, Shinji Suzuki, Tetsuaki Moriguchi, Daiki Kamioka, Natsuki Tadano, Yuri A. Litvinov, Akira Ozawa, Y. Yanagisawa, T. Fujii, Toshiya Mitsui, Takayuki Yamaguchi, Shin'ichiro Michimasa, and Hiroki Arakawa
- Subjects
Physics ,Atomic physics ,Ring (chemistry) - Published
- 2021
20. Development of Mirror-type MCP Detectors for Mass Measurements at the Rare-RI Ring
- Author
-
Akira Ozawa, Kumi Inomata, Takayuki Yamaguchi, Masanori Wakasugi, M. Amano, Z. Ge, Atsushi Kitagawa, Hongfu Li, S. Omika, Shinji Sato, M. Mukai, Takaaki Kobayashi, Daisuke Nagae, Giuseppe Lorusso, Yasushige Yano, Hiroki Arakawa, Kiyoshi Wakayama, Yasushi Abe, Tomohiro Uesaka, Yoshitaka Yamaguchi, Kunimitsu Nishimuro, F. Suzaki, S. Naimi, Shinji Suzuki, Tetsuaki Moriguchi, and Daiki Kamioka
- Subjects
Physics ,Optics ,business.industry ,Detector ,Development (differential geometry) ,Ring (chemistry) ,business - Published
- 2021
21. MCP with Delay-line Anode Used for Position Sensitive Detector at Rare RI Ring
- Author
-
Kumi Inomata, Takayuki Yamaguchi, Hongfu Li, Hiroki Arakawa, S. Naimi, Daisuki Nagae, Yoshitaka Yamaguchi, Shinji Suzuki, Shunichiro Omika, Kiyoshi Wakayama, Tomohiro Uesaka, F. Suzaki, Z. Ge, Masanori Wakasugi, Yasushi Abe, Akira Ozawa, and Tetsuaki Moriguchi
- Subjects
Physics ,Optics ,business.industry ,Position (vector) ,Detector ,Line (text file) ,Ring (chemistry) ,business ,Anode - Published
- 2021
22. Development of Experimental Devices for Precise Mass Measurements at the Rare-RI Ring Facility
- Author
-
Kunimitsu Nishimuro, Takayuki Yamaguchi, F. Suzaki, Shunichiro Omika, Kumi Inomata, Shinji Suzuki, Y. Yanagisawa, Hongfu Li, Akira Ozawa, M. Amano, Kiyoshi Wakayama, Sarah Naimi, Hiroki Arakawa, Tetsuaki Moriguchi, Masanori Wakasugi, Daiki Kamioka, Yasushi Abe, Natsuki Tadano, Toshio Suzuki, Hiroshi Miura, Z. Ge, Yoshitaka Yamaguchi, Daisuke Nagae, and Tomohiro Uesaka
- Subjects
Materials science ,business.industry ,Optoelectronics ,Experimental Devices ,business ,Ring (chemistry) - Published
- 2021
23. First spectroscopic study of V63 at the N=40 island of inversion
- Author
-
K. Moschner, David Steppenbeck, F. Browne, Jenny Lee, H. Törnqvist, Y. L. Sun, Kathrin Wimmer, Yuya Kubota, A. Gillibert, V. Panin, E. Sahin, L. X. Chung, D. Calvet, T. Isobe, Alessandra Corsi, Dóra Sohler, R.-B. Gerst, M. MacCormick, Yosuke Kondo, F. Château, Hideaki Otsu, P. Doornenbal, Hirofumi Yamada, N. Paul, V. Werner, Satoshi Takeuchi, M. L. Cortés, Masahiro Yasuda, D. M. Rossi, S. Franchoo, C. Lehr, W. Rodriguez, H. Baba, S. Y. Park, Z. Elekes, A. Giganon, Kazuyuki Ogata, Nobuyuki Chiga, Duo Yan, T. Lokotko, L. Zanetti, L. Stuhl, K. Yoneda, T. Koiwai, Takashi Nakamura, A. Delbart, Masaki Sasano, N. L. Achouri, S. Wang, B. D. Linh, Igor Gašparić, H. N. Liu, Yasuhiro Togano, V. Wagner, P. Koseoglou, F. Flavigny, J. M. Gheller, Tomohiro Uesaka, A. Obertelli, Zs. Dombrádi, Hiroyoshi Sakurai, T. Motobayashi, Julien Gibelin, Dong-Wook Kim, O. Aktas, V. Lapoux, K. Yoshida, M. M. Juhász, Kamila Sieja, Zaihong Yang, I. Murray, K. I. Hahn, T. Kobayashi, X. X. Xu, Si-Ge Chen, P. A. Söderström, Victor Vaquero, Thomas Aumann, and C. Hilaire
- Subjects
Physics ,010308 nuclear & particles physics ,Island of inversion ,0103 physical sciences ,Geophysics ,010306 general physics ,01 natural sciences - Published
- 2021
24. Erratum to: Proton density polarization of the doubly magic 40Ca core in 48Ca and EoS parameters
- Author
-
Hiroyuki Sagawa, Satoshi Yoshida, Juzo Zenihiro, and Tomohiro Uesaka
- Subjects
Physics ,Core (optical fiber) ,General Physics and Astronomy ,MAGIC (telescope) ,Atomic physics ,Proton density ,Polarization (waves) - Published
- 2021
25. Polarized Sources And Targets - Proceedings Of The Eleventh International Workshop
- Author
-
Akihiro Yoshimi, Tomohiro Uesaka, Hideyuki Sakai and Akihiro Yoshimi, Tomohiro Uesaka, Hideyuki Sakai
- Published
- 2007
26. Development of a new in-ring beam monitor in the Rare-RI Ring
- Author
-
M. Amano, Takayuki Yamaguchi, S. Omika, Akira Ozawa, Tomohiro Uesaka, Masanori Wakasugi, Daisuke Nagae, Natsuki Tadano, Kiyoshi Wakayama, Yoshitaka Yamaguchi, Tetsuaki Moriguchi, Yasushi Abe, Daiki Kamioka, F. Suzaki, S. Naimi, Toshio Suzuki, Shinji Suzuki, and Z. Ge
- Subjects
Nuclear and High Energy Physics ,Scintillation ,Materials science ,Photon ,Physics::Instrumentation and Detectors ,business.industry ,Scintillator ,Ring (chemistry) ,Secondary electrons ,Ion ,Optics ,Physics::Accelerator Physics ,business ,Instrumentation ,Storage ring ,Beam (structure) - Abstract
A beam monitor is developed at the Rare-RI Ring storage ring facility at the RI beam factory at RIKEN. Because the Rare-RI Ring stores only a single exotic ion according to the operation principle, conventional beam instruments cannot be employed. In the present study, we design a simple monitoring system to confirm particle storage. The system comprises a thin foil and scintillators with photon sensors. When an ion passes through the foil, secondary electrons, including δ -rays, are emitted and are detected by a set of scintillation detectors without any guiding field. A beam test using 78 Ge with 175 MeV/nucleon successfully demonstrates the periodic revolution of the stored ions.
- Published
- 2020
27. Development of a neutron detector with a high position resolution at intermediate energies
- Author
-
Tomotsugu Wakasa, Masanori Dozono, T. L. Tang, Tomohiro Uesaka, T. Taguchi, Hiroshi Tokieda, Tatsushi Shima, K. Miki, M. Itoh, Yuya Kubota, Y. Ono, Hiroyuki Miya, Hiroaki Matsubara, J. Yasuda, Juzo Zenihiro, Shuichi Ota, C. S. Lee, Takashi Wakui, Motoki Kobayashi, Kimiko Sekiguchi, Masaki Sasano, and Shoichiro Kawase
- Subjects
Physics ,Nuclear and High Energy Physics ,Photomultiplier ,Proton ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,business.industry ,020209 energy ,Resolution (electron density) ,Cyclotron ,Detector ,02 engineering and technology ,01 natural sciences ,law.invention ,Optics ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Neutron detection ,Neutron ,Nuclear Experiment ,business ,Instrumentation ,Beam (structure) - Abstract
A high position resolution neutron detector for time-of-flight measurements is being developed to measure the ( p , p n ) reaction in inverse kinematics with an excitation energy resolution of 1 MeV at the RIKEN RI Beam Factory. In this study, a new method based on the segmentation of the neutron detector part is employed to achieve a position resolution on the order of mm with a prototype neutron detector. The prototype detector consists of 8 × 8 scintillating fibers, two multi-anode photomultiplier tubes (PMTs) and two light guides. The scintillating fibers have a cross sectional area of 3 . 75 × 3 . 75 mm 2 . The prototype’s performance is studied using the neutron and proton beams provided at the Cyclotron and Radioisotope Center (CYRIC), Tohoku University and the Research Center for Nuclear Physics (RCNP), Osaka University. It is confirmed that the hit pattern analysis correctly recognizes the neutron detection position within the fiber size of 3.75 mm. The obtained TOF resolution of 350 ps (FWHM), lateral position resolution of 2.5 mm (FWHM), and longitudinal position resolution of 50–60 mm (FWHM) satisfy the requirements to achieve an excitation energy resolution of 1 MeV. The typical detection efficiency is ∼ 2.0% for a neutron with a kinetic energy of 50–200 MeV. The detailed investigation of the detection efficiency in conjunction with the neutron hit position reveals the existence of the non-uniformity of the efficiency. It is shown that the non-uniformity can be mitigated by reducing the threshold level, and by increasing the detector size. For a larger neutron detector, based on the design of the prototype detector, the non-uniformity will thus be negligible.
- Published
- 2019
28. Dynamic Nuclear Polarization of Metal–Organic Frameworks Using Photoexcited Triplet Electrons
- Author
-
Nobuhiro Yanai, Fujiwara Saiya, Tomohiro Uesaka, Keiko Ideta, Masanori Hosoyamada, Nobuo Kimizuka, and Kenichiro Tateishi
- Subjects
Thermal equilibrium ,Spins ,Nanoporous ,Chemistry ,Physics::Medical Physics ,02 engineering and technology ,General Chemistry ,Electron ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Biochemistry ,Catalysis ,0104 chemical sciences ,Pentacene ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Deuterium ,Chemical physics ,Proton NMR ,0210 nano-technology - Abstract
While dynamic nuclear polarization based on photoexcited triplet electrons (triplet-DNP) has the potential to hyperpolarize nuclear spins of target substrates in the low magnetic field at room temperature, there has been no triplet-DNP system offering structural rigidity and substrate accessibility. Here, we report the first example of triplet-DNP of nanoporous metal–organic frameworks. Accommodation of a carboxylate-modified pentacene derivative in a partially deuterated ZIF-8 (D-ZIF-8) results in a clear 1H NMR signal enhancement over thermal equilibrium.
- Published
- 2018
29. Experimental Study of $^{4}n$ by Directly Detecting the Decay Neutrons
- Author
-
Atsumi Saito, Yohei Shimizu, H. Törnqvist, B. Monteagudo, T. Isobe, M. Caamaño, H. Scheit, S. Kiyotake, J. Tscheuschner, M. L. Cortés, F. M. Marqués, N. Fukuda, N. A. Orr, J. M. Gheller, A. Gillibert, A. Matta, K. Yoneda, L. Stuhl, Z. Elekes, I. Kuti, V. Wagner, M. Miwa, Z. Halász, A. Obertelli, S. Kim, A. Revel, L. Zanetti, N. L. Achouri, S. Takeuchi, F. Dufter, C. A. Douma, S. Masuoka, Stefanos Paschalis, R. Gernhäuser, S. Chen, Nobuyuki Chiga, S. Storck, T. Shimada, M.N. Harakeh, P. Koseoglou, T. Harada, B. Yang, M. Matsumoto, H. Takeda, D. S. Ahn, Yuya Kubota, H. Yamada, Yasuhiro Togano, A. Hirayama, Y. Yasuda, T. Fujino, D. M. Rossi, Nasser Kalantar-Nayestanaki, J. Tanaka, M. Böhmer, N. Inabe, Didier Beaumel, S. Park, Thomas Aumann, H. Baba, Tomohiro Uesaka, F. Schindler, J. Feng, Zaihong Yang, I. Murray, Julien Gibelin, K. Boretzky, S. W. Huang, B. Fernández-Domínguez, S. Reichert, Takashi Nakamura, Yu-xin Liu, K. Wimmer, Yukie Maeda, L. Yang, H. Sato, E. Tronchin, P. Doornenbal, Dmytro Symochko, D. Cortina, J. Kahlbow, S. Shimoura, H. Suzuki, Hideaki Otsu, M. Potlog, P. J. Li, J. Mayer, H. Miki, Masaki Sasano, Toshio Kobayashi, Z. Ge, D. Kim, Juzo Zenihiro, T. Tomai, I. Stefan, M. Parlog, H. Simon, V. Panin, Igor Gašparić, C. Lehr, Yosuke Kondo, C. Lenain, U. Forsberg, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Research unit Nuclear & Hadron Physics, and Nuclear Energy
- Subjects
Nuclear structure and force ,tetraneutron ,direct reactions ,radioactive beams ,Physics ,Nuclear physics ,010308 nuclear & particles physics ,0103 physical sciences ,Tetraneutron ,Neutron ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,010306 general physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,3. Good health - Abstract
The tetraneutron has attracted the attention of nuclear physicists during the past decades, but there is still no unambiguous confirmation of its existence or non-existence. A new experiment based on $$^{8}$$ He(p, 2p) $$^{7}$$ H{t+ $$^{4}n$$ } reaction, with direct detection of the four neutrons, has been carried out at RIBF, which can hopefully help to draw a definite conclusion on the tetraneutron system.
- Published
- 2021
30. Quasifree Neutron Knockout Reaction Reveals a Small s -Orbital Component in the Borromean Nucleus B17
- Author
-
Shuichi Ota, V. Panin, A. Ohkura, Toshiyuki Sumikama, Y. Kiyokawa, Takashi Nakamura, J. Yasuda, T. Isobe, S. Kawakami, Y. Kanaya, Ji Feng, H. Sato, A. Giganon, K. Hasegawa, D. Kim, C. Caesar, Toshio Kobayashi, K. Yoneda, Masanori Dozono, Noritsugu Nakatsuka, Motoki Kobayashi, Juzo Zenihiro, Atsumi Saito, Tsuyoshi Miyazaki, Shoko Koyama, J.-Y. Roussé, Y.L. Sun, Z. Korkulu, Nagao Kobayashi, C. Santamaria, Y. Shindo, Stefanos Paschalis, F. Flavigny, Nicolas Michel, E. C. Pollacco, Yasuhiro Togano, A. Corsi, Yukie Maeda, C. X. Yuan, N. A. Orr, L. Stuhl, Hideaki Otsu, Shan-Gui Zhou, D. Calvet, Tomohiro Uesaka, F. M. Marqués, A. Delbart, G. Authelet, J. M. Gheller, M. Sako, Yohei Shimizu, Yuya Kubota, A. Gillibert, Y. Nishio, T. Ozaki, S. Reichert, J. Tsubota, Kazuyuki Ogata, Wei Zuo, Zaihong Yang, M. Shikata, K. Yoshida, Qiang Yuan, J. Gibelin, V. Lapoux, Masaki Sasano, H. Baba, Furong Xu, A. Obertelli, Masaaki Kimura, Xianping Sun, Yosuke Kondo, M. Tabata, T. Motobayashi, Satoshi Sakaguchi, and J. G. Li
- Subjects
Physics ,Component (thermodynamics) ,Nuclear Theory ,General Physics and Astronomy ,01 natural sciences ,Momentum ,Nuclear physics ,Atomic orbital ,Borromean nucleus ,0103 physical sciences ,Neutron ,Continuum (set theory) ,Halo ,010306 general physics ,Astrophysics::Galaxy Astrophysics - Abstract
A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.
- Published
- 2021
31. Proton density polarization of the doubly magic 40Ca core in 48Ca and EoS parameters
- Author
-
Hiroyuki Sagawa, Satoshi Yoshida, Tomohiro Uesaka, and Juzo Zenihiro
- Subjects
Physics ,Core (optical fiber) ,010308 nuclear & particles physics ,Nuclear Theory ,0103 physical sciences ,General Physics and Astronomy ,MAGIC (telescope) ,Atomic physics ,Nuclear Experiment ,010306 general physics ,Polarization (waves) ,Proton density ,01 natural sciences - Abstract
The proton density polarization in ${\rm ^{48}Ca}$ by the eight neutrons added on the ${\rm ^{40}Ca}$ core is discussed. We adopt the proton density distributions determined by electron scattering and the neutron density distributions determined by proton elastic scattering in ${\rm ^{40}Ca}$ and ${\rm ^{48}Ca}$. As a measure of the proton density polarization effect due to the neutrons, a ratio $R$ of the peak values of the neutron density difference $\Delta\rho_{n,{\rm peak}}$ between ${\rm ^{48}Ca}$ and ${\rm ^{40}Ca}$ to the proton one $\Delta\rho_{p,{\rm peak}}$ is introduced and compared with the Hartree–Fock and Hartree calculations by non-relativistic and relativistic energy density functionals (EDFs), respectively. The value $R$ shows clear correlations with the symmetry energy parameters $J$ and $L$, but not with the isoscalar incompressibility $K_\infty$. The experimental value $R$ can be reproduced by theoretical calculations using the EDFs with $L=25$–50 MeV.
- Published
- 2021
32. First spectroscopic study of $^{51}$Ar by the (p,2p) reaction
- Author
-
Zs. Dombradi, S. Y. Park, T. Isobe, F. Browne, K. Moschner, Thomas Aumann, R.-B. Gerst, F. Château, Kathrin Wimmer, X. X. Xu, Z. Elekes, L. Zanetti, Hideaki Otsu, B. D. Linh, Hirofumi Yamada, Si-Ge Chen, P. A. Söderström, Yutaka Utsuno, Igor Gašparić, H. N. Liu, Jenny Lee, Zaihong Yang, I. Murray, Yasuhiro Togano, F. Flavigny, K. I. Hahn, L. Stuhl, Yuya Kubota, V. Wagner, Tomohiro Uesaka, A. Giganon, D. Kim, M. MacCormick, C. Lehr, V. Panin, L. X. Chung, P. Koseoglou, T. Lokotko, Y.L. Sun, E. Sahin, K. Yoneda, Victor Vaquero, M. L. Cortés, Takashi Nakamura, S. Franchoo, P. Doornenbal, Satoshi Takeuchi, Masahiro Yasuda, O. Aktas, A. Gillibert, V. Lapoux, Nobuyuki Chiga, Takaharu Otsuka, T. Koiwai, Hiroyoshi Sakurai, T. Motobayashi, M. M. Juhász, Kazuki Yoshida, David Steppenbeck, Julien Gibelin, H. Törnqvist, Toshio Kobayashi, Kazuyuki Ogata, W. Rodriguez, N. L. Achouri, C. Hilaire, S. Wang, Donghang Yan, N. Paul, A. Obertelli, J. M. Gheller, Yosuke Kondo, V. Werner, D. Calvet, D. M. Rossi, Masaki Sasano, H. Baba, D. Sohler, A. Corsi, A. Delbart, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), RIKEN Nishina Center for Accelerator-Based Science, European Research Council, European Commission, Helmholtz International Center for FAIR, German Research Foundation, Alexander von Humboldt Foundation, Ministry of Science and Technology of Vietnam, Government of South Korea, Agencia Estatal de Investigación (España), Federal Ministry of Education and Research (Germany), Helmholtz Graduate School for Hadron and Ion Research, and National Research, Development and Innovation Office (Hungary)
- Subjects
Nuclear and High Energy Physics ,Shell closure ,γ -ray spectroscopy ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,01 natural sciences ,0103 physical sciences ,Bound state ,nuclear shell model ,proton knock-out reaction ,gamma-ray spectroscopy ,invariant-mass method ,radioactive beams ,Invariant mass ,Neutron ,ddc:530 ,Nuclear structure ,010306 general physics ,Spectroscopy ,Physics ,Valence (chemistry) ,Proton knock-out reaction ,010308 nuclear & particles physics ,Invariant mass method ,Isotopes of argon ,lcsh:QC1-999 ,Excited state ,γ-ray spectroscopy ,Atomic physics ,lcsh:Physics - Abstract
8 pags., 4 figs., 3 tabs., The nuclear structure of 51Ar, an uncharted territory so far, was studied by the (p,2p) reaction using γ-ray spectroscopy for the bound states and the invariant mass method for the unbound states. Two peaks were detected in the γ-ray spectrum and six peaks were observed in the 50Ar+n relative energy spectrum. Comparing the results to our shell-model calculations, two bound and six unbound states were established. Three of the unbound states could only be placed tentatively due to the low number of counts in the relative energy spectrum of events associated with the decay through the first excited state of 50Ar. The low cross sections populating the two bound states of 51Ar could be interpreted as a clear signature for the presence of significant subshell closures at neutron numbers 32 and 34 in argon isotopes. It was also revealed that due to the two valence holes, unbound collective states coexist with individual-particle states in 51Ar., We are very grateful to the RIKEN Nishina Center accelerator staff for providing the stable beam and to the BigRIPS team for the smooth operation of the secondary beams. The development of the MINOS device has been supported by the European Research Council through the ERC Grant No. MINOS-258567. F. B. was supported by the RIKEN Special Postdoctoral Researcher Program. K. O. acknowledges the support by Grant-in-Aid for Scientific Research JP16K05352. Y. U. acknowledges the support by Grant-in-Aid for Scientific Research 20K03981. Y. L. S. acknowledges the support of Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2015-705023) from the European Union and the support from the Helmholtz International Center for FAIR. H. N. L. acknowledges the support from the Enhanced Eurotalents program (PCOFUND-GA-2013-600382) co-funded by CEA and the European Union. T. A., C. L., D. R., H. T., V. W., L. Z., H. N. L., V. W. and A. O. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Project No. 279384907-SFB 1245. R. B. G. acknowledges the support from the DFG under Grant No. BL 1513/1-1. Y. L. S. and A. O. acknowledge the support from the Alexander von Humboldt Foundation. B. D. L. and L. X. C. acknowledge the support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. I. G. has been supported by HIC for FAIR and HRZZ under project No. 1257 and 7194. K. I. H., D. K. and S. Y. P. acknowledge the support from the NRF grant funded by the Korea government (No. 2017R1A2B2012382 and 2019M7A1A1033186). F. B. acknowledge the support from the RIKEN Special Postdoctoral Researcher Program. D. S. and Z. E. were supported by projects No. GINOP-2.3.3-15-2016-00034 and No. K128947. V. V. acknowledges support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. V. W. and P. K. acknowledge the support from BMBF grants 05P15RDFN1 and 05P19RDFN1. P. K. acknowledges support from HGS-HIRe. This work was also supported by NKFIH (114454).
- Published
- 2021
33. N=32 shell closure below calcium: Low-lying structure of Ar50
- Author
-
Nobuyuki Chiga, K. Moschner, T. Koiwai, Hiroyoshi Sakurai, V. Lapoux, A. Gillibert, Yutaka Utsuno, D. Calvet, T. Isobe, Kathrin Wimmer, T. Motobayashi, Jenny Lee, Achim Schwenk, H. Toernqvist, Yuya Kubota, Victor Vaquero, R.-B. Gerst, F. Château, W. Rodriguez, N. Shimizu, B. D. Linh, D. M. Rossi, Masahiro Yasuda, Tomohiro Uesaka, Hideaki Otsu, Igor Gašparić, H. N. Liu, V. Panin, H. Baba, Kazuyuki Ogata, L. X. Chung, S. Y. Park, Julien Gibelin, Hirofumi Yamada, K. Yoshida, C. Lehr, Duo Yan, L. Achouri, Zaihong Yang, L. Stuhl, A. Giganon, I. Murray, S. Wang, N. Paul, L. Zanetti, E. Sahin, Y. L. Sun, J. Simonis, A. Obertelli, K. Yoneda, C. Hilaire, K. I. Hahn, V. Werner, David Steppenbeck, Jason D. Holt, P. Doornenbal, A. Delbart, M. MacCormick, P. Koseoglou, J. M. Gheller, Alessandra Corsi, Thomas Aumann, Masaki Sasano, Dóra Sohler, Satoshi Takeuchi, M. L. Cortés, S. Franchoo, T. Kobayashi, F. Flavigny, X. X. Xu, Si-Ge Chen, P. A. Söderström, Dong-Wook Kim, F. Browne, O. Aktas, Yosuke Kondo, Yasuhiro Togano, T. Lokotko, Takashi Nakamura, Javier Fernandez Menendez, and V. Wagner
- Subjects
Physics ,010308 nuclear & particles physics ,0103 physical sciences ,Closure (topology) ,Shell (structure) ,Calcium low ,010306 general physics ,01 natural sciences ,Molecular physics - Published
- 2020
34. Surface Localization of the Dineutron in Li11
- Author
-
V. Lapoux, Nagao Kobayashi, Stefanos Paschalis, A. Ohkura, C. Caesar, Atsumi Saito, K. Yoneda, Masanori Dozono, Y. L. Sun, A. Obertelli, J. Tsubota, Zaihong Yang, Yohei Shimizu, M. Shikata, H. Baba, Masaki Sasano, L. Stuhl, Y. Kikuchi, T. Ozaki, F. M. Marqués, J. Yasuda, Toshio Kobayashi, V. Panin, S. Reichert, M. Tabata, Noritsugu Nakatsuka, G. Authelet, T. Motobayashi, C. Santamaria, D. Calvet, Juzo Zenihiro, N. A. Orr, T. Isobe, E. C. Pollacco, Tomohiro Uesaka, Yuya Kubota, J. M. Gheller, A. Gillibert, Motoki Kobayashi, Shoko Koyama, Hideaki Otsu, Toshiyuki Sumikama, K. Hasegawa, Z. Korkulu, Julien Gibelin, Y. Kiyokawa, Yosuke Kondo, M. Sako, A. Corsi, Satoshi Sakaguchi, A. Giganon, Y. Nishio, A. Delbart, S. Kawakami, Shuichi Ota, F. Flavigny, Yukie Maeda, Takashi Nakamura, Ji Feng, H. Sato, J.-Y. Roussé, Yasuhiro Togano, Kazuyuki Ogata, D. Kim, Y. Kanaya, Tsuyoshi Miyazaki, and Y. Shindo
- Subjects
Surface (mathematics) ,Physics ,Nuclear Theory ,General Physics and Astronomy ,Nuclear matter ,7. Clean energy ,01 natural sciences ,Nuclear physics ,Momentum ,medicine.anatomical_structure ,0103 physical sciences ,medicine ,Neutron ,Nuclear Experiment ,010306 general physics ,Nucleon ,Nucleus - Abstract
The formation of a dineutron in the nucleus $^{11}$Li is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in $^{11}$Li via the $(p,pn)$ knockout reaction at 246 MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at $r\sim3.6$ fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.
- Published
- 2020
35. Trajectory in 2D plot of isoscalar and isovector densities of Ca48 and Pb208 , and symmetry energy
- Author
-
Tomohiro Uesaka, Juzo Zenihiro, Hiroyuki Sagawa, and Satoshi Yoshida
- Subjects
Physics ,Isovector ,Proton ,010308 nuclear & particles physics ,Isoscalar ,Nuclear Theory ,Quadratic function ,01 natural sciences ,Symmetry (physics) ,Isospin ,0103 physical sciences ,Neutron ,010306 general physics ,Energy (signal processing) ,Mathematical physics - Abstract
We propose a new two-dimensional (2D) plotting method of isoscalar-isovector (IS-IV) densities of $^{48}\mathrm{Ca}$ and $^{208}\mathrm{Pb}$ to extract not only empirical symmetry energy coefficients $J, L$, and ${K}_{\mathrm{sym}}$ but also the asymmetric isospin term ${K}_{\ensuremath{\tau}}$ in the nuclear incompressibility. We adopted several modern relativistic and nonrelativistic energy density functional (EDF) for the theoretical calculations of IS and IV densities to compare with experimental neutron and proton density distributions determined by recent proton elastic scatterings. We found very strong correlations between the trajectory of the 2D density at the density $\ensuremath{\rho}=0.1\phantom{\rule{4pt}{0ex}}{\mathrm{fm}}^{\ensuremath{-}3}$ and the symmetry energy coefficients $J, L$, and also ${K}_{\ensuremath{\tau}}$. For ${K}_{\mathrm{sym}}$, the Skyrme EDF SAMi-J family shows a strong correlation in the trajectory of 2D density, while the RMF Lagrangian DDME-J family shows a peculiar quadratic curve and does not provide the experimental value. The symmetry energy term ${K}_{\ensuremath{\tau}}$ of nuclear incompressibility is also discussed in term of the slope of 2D trajectory.
- Published
- 2020
36. Mass measurements for the Tz=−2fp -shell nuclei Ti40 , Cr44 , Mn46 , Fe48 , Co50 , and Ni52
- Author
-
Yu. A. Litvinov, Xurong Xu, Xiao-Lin Tu, Shigeru Kubono, Y. H. Zhang, M. Wang, A. Ozawa, W. L. Zhan, Bao-Hua Sun, G. Audi, X. C. Chen, Jiuyang He, Yu Sun, C. Y. Fu, Takayuki Yamaguchi, Klaus Blaum, Qingqi Zeng, Y. M. Xing, Y. H. Lam, M. Z. Sun, Tomohiro Uesaka, H. S. Xu, X. L. Yan, R.J. Chen, X. K. Zhou, Ping Shuai, Sergey Litvinov, Furong Xu, and X. H. Zhou
- Subjects
Physics ,010308 nuclear & particles physics ,Order (ring theory) ,State (functional analysis) ,01 natural sciences ,Mass formula ,Isospin ,0103 physical sciences ,Isobaric process ,Atomic physics ,Anomaly (physics) ,010306 general physics ,Multiplet ,Storage ring - Abstract
By using isochronous mass spectrometry (IMS) at the experimental cooler storage ring CSRe, masses of short-lived $^{44}$Cr, $^{46}$Mn, $^{48}$Fe, $^{50}$Co and $^{52}$Ni were measured for the first time and the precision of the mass of $^{40}$Ti was improved by a factor of about 2. Relative precisions of $\delta m/m=(1-2)\times$10$^{-6}$ have been achieved. Details of the measurements and data analysis are described. The obtained masses are compared with the Atomic-Mass Evaluation 2016 (AME$^{\prime}$16) and with theoretical model predictions. The new mass data enable us to extract the higher order coefficients, $d$ and $e$, of the quartic form of the isobaric multiplet mass equation (IMME) for the $fp$-shell isospin quintets. Unexpectedly large $d$- and $e$-values for $A=44$ quintet are found. By re-visiting the previous experimental data on $\beta$-delayed protons from $^{44}$Cr decay, it is suggested that the observed anomaly could be due to the misidentification of the $T=2$, $J^\pi=0^{+}$ isobaric analog state (IAS) in $^{44}$V.
- Published
- 2020
37. 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
38. Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei
- Author
-
Megumi Niikura, K. Yoneda, Tomohiro Uesaka, T. Miyazaki, J.-Y. Roussé, A. Jungclaus, I. G. Stefan, Masaki Sasano, A. Gillibert, Jian Liu, Hiroyoshi Sakurai, David Steppenbeck, Zs. Dombradi, K. Moschner, M. Gómez-Ramos, Satoshi Takeuchi, D. Calvet, T. Isobe, Shunji Nishimura, T. Saito, V. Lapoux, H. Wang, T. Motobayashi, L. Olivier, R. Lozeva, A. Gottardo, S. Franchoo, C. Péron, H. Baba, Jinguang Wu, G. Authelet, A. Delbart, A. Blazhev, J. M. Gheller, Hideaki Otsu, F. Château, Masafumi Matsushita, Zs. Vajta, Zena Patel, Victor Vaquero, Kathrin Wimmer, M. L. Cortés, K. Matsui, Shuichi Ota, C. Santamaria, E. C. Pollacco, M. Dewald, Alessandra Corsi, F. Browne, C. R. Nita, M. Rudigier, Z. Korkulu, Jenny Lee, Yoshiaki Shiga, K. Hadynska-Klek, S. Nagamine, Satoru Momiyama, A. Frotscher, T. Arici, Ryo Taniuchi, Noritaka Shimizu, C. R. Nobs, Toshiyuki Sumikama, Alison Bruce, C. Louchart, E. Sahin, Toshiaki Ando, Zhenci Xu, F. Giacoppo, Y. Kubota, L. X. Chung, B. D. Linh, P. Doornenbal, F. Flavigny, A. Giganon, N. Paul, C. M. Shand, Noritsugu Nakatsuka, Zi Hong Liu, V. Werner, M. Górska, Si-Ge Chen, P. A. Söderström, D. Suzuki, M. Lettmann, R. Orlandi, C. Lizarazo, A. Obertelli, Raymond J. Carroll, Bing Ding, Zs. Podolyák, Shoko Koyama, and Alan Peyaud
- Subjects
Physics ,Hydrogen ,Proton ,Projectile ,Nuclear Theory ,General Physics and Astronomy ,chemistry.chemical_element ,01 natural sciences ,Coincidence ,Nuclear physics ,medicine.anatomical_structure ,chemistry ,MINOS ,0103 physical sciences ,medicine ,Neutron ,Nuclear Experiment ,010306 general physics ,Nucleon ,Nucleus - Abstract
Twenty-one two-proton knockout (p; 3p) cross sections from neutron-rich nuclei at ~ 250 MeV/nucleon were measured. For the first time, the angular distribution of the three emitted protons were measured in coincidence with the tracker and hydrogen target MINOS, demonstrating that the (p; 3p) kinematics is consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p; 3p) over (p; 2p) inclusive cross sections follow the trend of other many-proton (neutron) removal reactions, further reinforcing the sequential nature of (p; 3p) in neutron-rich nuclei.
- Published
- 2020
39. Materials chemistry of triplet dynamic nuclear polarization
- Author
-
Tomohiro Uesaka, Nobuhiro Yanai, Fujiwara Saiya, Kana Orihashi, Hironori Kouno, Yusuke Kawashima, Koki Nishimura, Kenichiro Tateishi, and Nobuo Kimizuka
- Subjects
Solid-state chemistry ,Materials science ,Magnetic Resonance Spectroscopy ,Surface Properties ,Physics::Medical Physics ,Nanotechnology ,Electrons ,Electron ,Catalysis ,Nanomaterials ,Electromagnetic Fields ,Materials Chemistry ,Hyperpolarization (physics) ,Metal-Organic Frameworks ,Nanoporous ,Metals and Alloys ,Electron Spin Resonance Spectroscopy ,Temperature ,Water ,General Chemistry ,Models, Theoretical ,Polarization (waves) ,Moderate temperature ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nanocrystal ,Solubility ,Ceramics and Composites ,Nanoparticles ,Porosity - Abstract
Dynamic nuclear polarization with photo-excited triplet electrons (triplet-DNP) has the potential to enhance the sensitivity of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) at a moderate temperature. While many efforts have been devoted to achieving a large nuclear polarization based on triplet-DNP, the application of triplet-DNP has been limited to nuclear physics experiments. The recent introduction of materials chemistry into the field of triplet-DNP has achieved air-stable and water-soluble polarizing agents as well as the hyperpolarization of nanomaterials with a large surface area such as nanoporous metal–organic frameworks (MOFs) and nanocrystal dispersion in water. This Feature Article overviews the recently-emerged materials chemistry of triplet-DNP that paves new paths towards unprecedented biological and medical applications.
- Published
- 2020
40. Metastable States of Se92,94 : Identification of an Oblate K Isomer of Se94 and the Ground-State Shape Transition between N=58 and 60
- Author
-
L. Olivier, I. Kojouharov, G. Authelet, J. M. Gheller, V. Lapoux, Jenny Lee, J.-Y. Roussé, J. Gerl, C. Lizarazo, N. Paul, Noritsugu Nakatsuka, Hiroyoshi Sakurai, H. Schaffner, P. M. Walker, Zi Hong Liu, V. Werner, David Steppenbeck, T. Motobayashi, A. Blazhev, P. Doornenbal, Shunji Nishimura, I. Stefan, M. L. Cortés, T. Arici, J. J. Liu, Tomás R. Rodríguez, Alison Bruce, A. Giganon, C. Santamaria, F. Château, Megumi Niikura, Zhengyu Xu, F. Browne, Tomohiro Uesaka, M. Rudigier, C. R. Niţă, P. A. Söderström, Zena Patel, T. Saito, N. Kurz, M. Górska, S. Franchoo, A. Gillibert, G. X. Dong, A. Gottardo, C. M. Shand, Satoru Momiyama, L. X. Chung, C. R. Nobs, B. D. Linh, S. Nagamine, Ryo Taniuchi, A. Obertelli, M. Dewald, K. Moschner, Kathrin Wimmer, H. Baba, R. J. Caroll, D. Calvet, F. Flavigny, Bing Ding, Zs. Podolyák, Furong Xu, Toshiaki Ando, Si-Ge Chen, Victor Vaquero, M. Lettmann, A. Corsi, Norbert Pietralla, and A. Delbart
- Subjects
Physics ,010308 nuclear & particles physics ,General Physics and Astronomy ,chemistry.chemical_element ,Germanium ,01 natural sciences ,Hafnium ,medicine.anatomical_structure ,chemistry ,Atomic orbital ,Metastability ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,medicine ,Neutron ,Atomic physics ,Nuclear Experiment ,010306 general physics ,Ground state ,Spectroscopy ,Nucleus - Abstract
Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.
- Published
- 2020
41. 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
42. Angular and energy dependence of $A_y$, $A_{yy}$ and $A_{xx}$ analyzing powers in dp elastic scattering and dp breakup reaction investigation
- Author
-
Olena Mezhenska, J. T. Karachuk, Yaroslav T. Skhomenko, Marian Janek, E. V. Chernykh, M. Janek, D. Enache, A. N. Livanov, A. Isupov, V. P. Ladygin, D. O. Krivenkov, N. B. Ladygina, A. A. Terekhin, P. K. Kurilkin, Yury Gurchin, A. V. Tishevsky, S. M. Piyadin, S. G. Reznikov, A. V. Averyanov, and Tomohiro Uesaka
- Subjects
Physics ,Elastic scattering ,Atomic physics ,Breakup ,Energy (signal processing) - Published
- 2020
43. Polarized proton spin filter for epithermal neutron based on dynamic nuclear polarization using photo-excited triplet electron spins
- Author
-
Yoshimasa Ikeda, Yoshie Otake, Shusuke Takada, Tamaki Yoshioka, Tomohiro Uesaka, Yasuo Wakabayashi, and Kenichiro Tateishi
- Subjects
Physics ,Physics - Instrumentation and Detectors ,Spins ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,FOS: Physical sciences ,General Physics and Astronomy ,Instrumentation and Detectors (physics.ins-det) ,Electron ,Polarization (waves) ,Epithermal neutron ,01 natural sciences ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Excited state ,0103 physical sciences ,Proton spin crisis ,Nuclear Experiment (nucl-ex) ,Atomic physics ,010306 general physics ,Nuclear Experiment - Abstract
To polarize neutrons with energy beyond 0.1 eV, we developed a novel polarized proton spin filter based on dynamic nuclear polarization using photo-excited triplet electron spins. The spin filter consists of a single crystal of naphthalene doped with deuterated pentacene and has a size of $\varnothing15\times4 \, {\rm mm}^3$, allowing it to cover a wide beam diameter. It was operated in 0.35 T and at 90 K. We succeeded in polarizing neutrons in the energy range 0.1–10 eV using a RIKEN accelerator-driven compact neutron source. The averaged values of the proton and neutron polarization were $0.250\pm0.050$ and $0.076\pm0.015$, respectively.
- Published
- 2020
44. Extending the Southern Shore of the Island of Inversion to F28
- Author
-
J. Mayer, Noritsugu Nakatsuka, Michael Thoennessen, A. Gillibert, Ákos Horváth, Q. Deshayes, Yosuke Kondo, J. Tscheuschner, Nasser Kalantar-Nayestanaki, J. M. Gheller, István Kuti, M. Shikata, Thomas Aumann, C. Caesar, J. Tsubota, A. Revel, N. L. Achouri, W. He, Z. Elekes, Calem Hoffman, Shoichiro Kawase, Heiko Scheit, J. Kahlbow, Masahiro Yasuda, H. Simon, H. Sato, K. Yoneda, A. Horvat, K. Nakano, Igor Gašparić, T. Ozaki, H. Chae, J. A. Tostevin, L. Stuhl, K. Miki, F. de Oliveira Santos, H. L. Crawford, D. Calvet, Stefanos Paschalis, S. Masuoka, T. Isobe, A. Obertelli, Tomoki Saito, Momoko Tanaka, N. A. Orr, Shoko Koyama, Nobuyuki Chiga, L. Atar, Y. Satou, P. Fallon, Atsumi Saito, Zsolt Dombrádi, H. Törnqvist, Jongwon Hwang, A. Corsi, Julien Gibelin, K. Boretzky, A. Delbart, D. M. Rossi, H. Baba, Masaki Sasano, D. Sohler, V. Lapoux, M. A. Najafi, S. K. Kim, A. Hirayama, H. Al Falou, K. Kisamori, T. Tomai, V. Panin, P. Schrock, Takashi Nakamura, Yasuhiro Togano, M.N. Harakeh, M. Holl, Zaihong Yang, F. Nowacki, T. Kobayashi, Cenxi Yuan, D. Körper, Tomohiro Uesaka, Thomas Nilsson, C. A. Douma, Simon Lindberg, Hideaki Otsu, O. Sorlin, T. Murakami, Yohei Shimizu, Fabia Schindler, Franck Delaunay, F. M. Marqués, and Satoshi Takeuchi
- Subjects
Physics ,Proton ,Island of inversion ,General Physics and Astronomy ,01 natural sciences ,Spectral line ,Momentum ,0103 physical sciences ,Neutron ,Atomic physics ,010306 general physics ,Nucleon ,Spectroscopy ,Ground state - Abstract
Detailed spectroscopy of the neutron-unbound nucleus 28 F has been performed for the first time following proton/neutron removal from 29 Ne / 29 F beams at energies around 230 MeV / nucleon . The invariant-mass spectra were reconstructed for both the 27 F ( * ) + n and 26 F ( * ) + 2 n coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the 28 F ground state, with S n ( 28 F ) = − 199 ( 6 ) keV , while analysis of the 2 n decay channel allowed a considerably improved S n ( 27 F ) = 1620 ( 60 ) keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of 28 F . Importantly, in the case of the ground state, the reconstructed 27 F + n momentum distribution following neutron removal from 29 F indicates that it arises mainly from the 1 p 3 / 2 neutron intruder configuration. This demonstrates that the island of inversion around N = 20 includes 28 F , and most probably 29 F , and suggests that 28 O is not doubly magic.
- Published
- 2020
45. Shell structure of the neutron-rich isotopes Co69,71,73
- Author
-
M. Lettmann, A. Gillibert, Alessandra Corsi, David Steppenbeck, S. Leblond, Yoshiaki Shiga, K. Yoshida, Toshiyuki Sumikama, Ryo Taniuchi, A. Gottardo, F. Nowacki, Jenny Lee, V. Lapoux, Yuya Kubota, C. Péron, A. Delbart, Shunji Nishimura, G. Authelet, Si-Ge Chen, P. A. Söderström, C. Louchart, J. M. Gheller, T. Miyazaki, Alan Peyaud, C. M. Shand, Satoshi Takeuchi, Masafumi Matsushita, F. Giacoppo, H. Baba, Satoru Momiyama, S. Franchoo, E. Sahin, Zhenci Xu, Jinguang Wu, Shuichi Ota, V. Werner, Hideaki Otsu, Alfredo Poves, L. X. Chung, Megumi Niikura, C. Santamaria, Tomohiro Uesaka, I. Stefan, K. Matsui, P. Doornenbal, Kazuyuki Ogata, F. Browne, Masaki Sasano, Zs. Dombrádi, Shoko Koyama, Z. Korkulu, Zs. Vajta, K. Hadynska-Klek, T. Lokotko, Z. Patel, L. Olivier, H. Wang, R. Lozeva, A. Obertelli, Hiroyoshi Sakurai, T. Motobayashi, E. C. Pollacco, J.-Y. Roussé, D. Calvet, T. Isobe, F. Château, and Daisuke Suzuki
- Subjects
Physics ,Isotope ,010308 nuclear & particles physics ,Nuclear structure ,Impulse (physics) ,7. Clean energy ,01 natural sciences ,Coincidence ,Nuclear physics ,MINOS ,0103 physical sciences ,Neutron ,Detector array ,Nuclear Experiment ,010306 general physics ,Excitation - Abstract
The structures of the neutron-rich Co69,71,73 isotopes were investigated via (p,2p) knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Isotopes of interest were studied using the DALI2 γ-ray detector array combined with the MINOS target and tracker system. Level schemes were reconstructed using the γ-γ coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations using the Lenzi-Nowacki-Poves-Sieja LNPS and PFSDG-U interactions suggests coexistence of spherical and deformed shapes at low excitation energies in the Co69,71,73 isotopes. The distorted-wave impulse approximation (DWIA) framework was used to calculate the single-particle cross sections. These values were compared with the experimental findings.
- Published
- 2020
46. Search for α-cluster States in 13C
- Author
-
Takahiro Kawabata, Hiroaki Matsubara, Kenji Suda, Kichiji Hatanaka, Yoshiko Sasamoto, K. Inaba, Keigo Kawase, Mamoru Fujiwara, Tomohiro Uesaka, Hidetomo Yoshida, Y. Shimizu, Atsushi Tamii, K. Itoh, Masatoshi Itoh, Yuji Tameshige, K. Nakanishi, Satoshi Sakaguchi, Makoto Uchida, and Yukie Maeda
- Subjects
Physics ,Cluster (physics) ,Molecular physics - Published
- 2020
47. Latest results concerning short range correlations obtained in the dp elastic and dp breakup processes at Nuclotron, JINR
- Author
-
Alexei N. Livanov, Olena Mezhenska, D. Enache, Dimitry O. Krivenkov, Eugene V. Chernykh, A. A. Terekhin, N. B. Ladygina, J. T. Karachuk, Alexander V. Averyanov, Marian Janek, S. M. Piyadin, V. P. Ladygin, A. N. Khrenov, S. G. Reznikov, Alexei V. Tishevsky, Yuri V. Gurchin, P. K. Kurilkin, A. Isupov, Tomohiro Uesaka, and Yaroslav T. Skhomenko
- Subjects
Physics ,Nuclear physics ,Nuclotron ,Range (particle radiation) ,010308 nuclear & particles physics ,QC1-999 ,0103 physical sciences ,Nuclear Theory ,010306 general physics ,Breakup ,Nuclear Experiment ,01 natural sciences - Abstract
Deuteron spin structure program is aimed on extraction of two and three nucleon forces information, including their spin dependent parts, from dp elastic and dp breakup processes investigated at intermediate energies. The dp elastic data were obtained at Internal Target Station of Nuclotron (JINR) in the energy range 400-1800 MeV using polarized deuteron beam. Strong sensitivity to the short range spin structure of the isoscalar nucleon-nucleon correlations is observed in deuteron analyzing powers. Preliminary results of the the cross section for the dp breakup reaction have been obtained at 400 MeV of deuteron energy.
- Published
- 2020
48. Compelete Set of Deuteron Analyzing Powers for dp Elastic Scattering at 70–300 MeV/nucleon and Three-Nucleon Forces
- Author
-
S. Kawakami, Y. Shimizu, Kimiko Sekiguchi, Masanori Dozono, E. Milman, H. Okamura, Yukie Maeda, A. Watanabe, Hideyuki Sakai, Kenjiro Miki, Masaki Sasano, H. Kon, Yuya Kubota, T. Akieda, Kentaro Yako, Tatsuya Yamamoto, Tomotsugu Wakasa, N. Sakamoto, Y. Shindo, T. L. Tang, Hiroshi Suzuki, D. Eto, Satoshi Sakaguchi, M. Tabata, Y. Yanagisawa, Shoichiro Kawase, A. Ohkura, J. Yasuda, Tomohiro Uesaka, S. Chebotaryov, and Y. Wada
- Subjects
Nuclear physics ,Physics ,Set (abstract data type) ,Elastic scattering ,Deuterium ,Nucleon - Published
- 2020
49. Shell evolution of $N=40$ isotones towards $^{60}$Ca: First spectroscopy of $^{62}$Ti
- Author
-
Masaki Sasano, S. M. Lenzi, Kazuki Yoshida, E. Sahin, V. Wagner, Hiroyoshi Sakurai, F. Nowacki, T. Isobe, W. Rodriguez, P. Doornenbal, Donghang Yan, D. Kim, T. Motobayashi, M.L. Cortés, Jason D. Holt, V. Lapoux, D. M. Rossi, Toshio Kobayashi, F. Flavigny, A. Giganon, B. D. Linh, F. Château, V. Panin, H. Baba, N. Paul, L. X. Chung, D. Calvet, X. X. Xu, David Steppenbeck, V. Werner, Igor Gašparić, H. N. Liu, A. Delbart, Yosuke Kondo, Si-Ge Chen, L. Achouri, Julien Gibelin, Tomohiro Uesaka, J. M. Gheller, A. Corsi, S. R. Stroberg, Alfredo Poves, Achim Schwenk, Satoshi Takeuchi, Thomas Aumann, R.-B. Gerst, C. Lehr, Jenny Lee, Yasuhiro Togano, C. Hilaire, Y.L. Sun, P. Koseoglou, Nobuyuki Chiga, K. Yoneda, F. Browne, Victor Vaquero, Yuya Kubota, T. Lokotko, T. Koiwai, Zaihong Yang, Takashi Nakamura, S. Wang, J. Simonis, I. Murray, Javier Fernandez Menendez, A. Obertelli, Kazuyuki Ogata, A. Gillibert, H. Toernqvist, M. MacCormick, Masahiro Yasuda, Hideaki Otsu, K. I. Hahn, L. Stuhl, O. Aktas, Hirofumi Yamada, Dóra Sohler, S. Franchoo, Tomás R. Rodríguez, L. Zanetti, K. Moschner, Kathrin Wimmer, S. Y. Park, P. A. Söderström, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), 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 corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), 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), UAM. Departamento de Física Teórica, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), RIKEN Nishina Center for Accelerator-Based Science, Japan Society for the Promotion of Science, Ministerio de Ciencia, Innovación y Universidades (España), Ministry of Science and Technology of Vietnam, Helmholtz International Center for FAIR, Croatian Science Foundation, National Research, Development and Innovation Office (Hungary), Ministerio de Economía y Competitividad (España), National Research Foundation of Korea, European Commission, Natural Sciences and Engineering Research Council of Canada, Federal Ministry of Education and Research (Germany), and National Research Council of Canada
- Subjects
Nuclear and High Energy Physics ,Nuclear Theory ,Ab initio ,FOS: Physical sciences ,Shell evolution ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,7. Clean energy ,01 natural sciences ,Radioactive beams ,Gamma-ray spectroscopy ,Nuclear Theory (nucl-th) ,0103 physical sciences ,ddc:530 ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Spectroscopy ,Nuclear Experiment ,Physics ,010308 nuclear & particles physics ,Island of inversion ,Isotone ,Starke Wechselwirkung und exotische Kerne – Abteilung Blaum ,Física ,lcsh:QC1-999 ,Excited state ,Quadrupole ,Atomic physics ,Nucleon ,Ground state ,lcsh:Physics - Abstract
7 pags., 4 figs., 1 tab., Excited states in the N=40 isotone Ti were populated via the V(p,2p)Ti reaction at ∼200 MeV/nucleon at the Radioactive Isotope Beam Factory and studied using γ-ray spectroscopy. The energies of the 2 →0 and 4 →2 transitions, observed here for the first time, indicate a deformed Ti ground state. These energies are increased compared to the neighboring Cr and Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for Ti show a dominant configuration with four neutrons excited across the N=40 gap. Likewise, they indicate that the N=40 island of inversion extends down to Z=20, disfavoring a possible doubly magic character of the elusive Ca., We thank the RIKEN Nishina Center accelerator staff and the Bi-gRIPS team for the stable operation of the high-intensity Zn beam and for the preparation of the secondary beam setting. K.O. ac-knowledges the support by Grant-in-Aid for Scientific Research of the Japan Society for the Promotion of Science (JSPS) JP16K05352. A.P. is supported in part by the Ministerio de Ciencia, Innovación y Universidades (Spain), Severo Ochoa Programme SEV-2016-0597 and grant PGC-2018-94583. F.B. is supported by the RIKEN Spe-cial Postdoctoral Researcher Program. L.X.C. and B.D.L. would like to thank the Vietnam Ministry of Science and Technology (MOST) for its support through the Physics Development Program Grant No. ÐTÐLCN.25/18. I.G. has been supported by HIC for FAIR and Croatian Science Foundation under projects no. 1257 and 7194. D. So. was supported by the the European Regional Develop-ment Fund contract No. GINOP-2.3.3-15-2016-00034 and the National Research, Development and Innovation Fund of Hungary via Project No. K128947. V.V. acknowledges support from the Span-ish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. K.I.H., D.K. and S.Y.P. acknowledge the sup-port from the National Research Foundation of Korea grant No. 2018R1A5A1025563 and 2019M7A1A1033186. The development of MINOS was supported by the European Research Council through the ERC Grant No. MINOS-258567. This work was also supported by the JSPS KAKENHI Grant No. 18K03639, MEXT as “Priority is-sue on post-K computer” (Elucidation of the fundamental laws and evolution of the universe), the Joint Institute for Computational Fundamental Science (JICFuS), the CNS-RIKEN joint project for large-scale nuclear structure calculations, Natural Sciences and Engineering Research Council (NSERC) of Canada, the Deutsche Forschungsgemeinschaft – Projektnummer 279384907 – SFB 1245, the PRISMA Cluster of Excellence, and the BMBF under Contracts No. 05P18RDFN1 and 05P19RDFN1. TRIUMF receives funding via a contribution through the National Research Council Canada. Com-putations were performed at the Jülich Supercomputing Center (JURECA)
- Published
- 2020
50. Measurement for p–$$^3$$He Elastic Scattering with a 65 MeV Polarized Proton Beam
- Author
-
H. Kon, T. Taguchi, S. N. Nakamura, Kimiko Sekiguchi, S. Goto, A. Inoue, Nobuyuki Kobayashi, S. Shibuya, Hooi Jin Ong, H. Ohshiro, T. Ino, Kichiji Hatanaka, S. Nakai, Tomohiro Uesaka, Makoto Watanabe, T. Mukai, K. Kawahara, Tomotsugu Wakasa, T. Akieda, T. Wakui, Y. Wada, Yukie Maeda, S. Mitsumoto, Y. Shiokawa, Kenjiro Miki, A. Watanabe, Hideyuki Sakai, D. Eto, Atsushi Tamii, D. Sakai, and M. Ito
- Subjects
Nuclear physics ,Elastic scattering ,Physics ,Cross section (physics) ,Proton ,Nuclear Theory ,Physics::Accelerator Physics ,Nuclear Experiment ,Beam (structure) - Abstract
We performed the measurement of the cross section and the proton analyzing power \(A_y\) for p–\(^3\)He elastic scattering with a 65 MeV polarized proton beam at Research Center for Nuclear Physics (RCNP), Osaka University. The proton analyzing power \(A_y\) data are compared with the theoretical calculations based on the nucleon–nucleon potential (INOY04).
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.