研究者詳細 - 吉見　彰洋

論文 - 吉見　彰洋

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A method to detect the VUV photons from cooled 229Th:CaF<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si16.svg" display="inline" id="d1e109"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math> crystals

Ming Guan, Michael Bartokos, Kjeld Beeks, Yuta Fukunaga, Takahiro Hiraki, Takahiko Masuda, Yuki Miyamoto, Ryoichiro Ogake, Koichi Okai, Noboru Sasao, Fabian Schaden, Thorsten Schumm, Kotaro Shimizu, Sayuri Takatori, Akihiro Yoshimi, Koji Yoshimura

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 562 165647 - 165647 2025年5月

Characterization of the thorium-229 defect structure in CaF₂ crystals

Sayuri Takatori, Martin Pimon, Stephan Pollitt, Michael Bartokos, Kjeld Beeks, Andreas Grüneis, Takahiro Hiraki, Tetsuo Honma, Niyusha Hosseini, Adrian Leitner, Takahiko Masuda, Ira Morawetz, Kiyofumi Nitta, Koichi Okai, Thomas Riebner, Fabian Schaden, Thorsten Schumm, Oki Sekizawa, Tomas Sikorsky, Yoshio Takahashi, Luca Toscani De Col, Rei Yamamoto, Takumi Yomogida, Akihiro Yoshimi, Koji Yoshimura

New Journal of Physics 2025年4月

掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing

Abstract

Recent advancements in laser excitation of the low-energy thorium-229 (²²⁹Th) nuclear isomeric state in calcium fluoride (CaF₂) single crystals render this system a promising candidate for a solid-state nuclear clock. Nonetheless, the precise experimental determination of the microscopic ion configuration surrounding the doped ²²⁹Th and its electronic charge state remains a critical challenge. Such characterization is essential for accurately controlling the clock transition and evaluating the performance of this solid-state nuclear clock system. In this study, we use x-ray absorption fine structure spectroscopy of ²²⁹Th:CaF₂ to investigate the charge state and coordination environment of doped ²²⁹Th. The results indicate that ²²⁹Th displays a 4+ oxidation state at the substitutional site of a Ca²⁺ ion, with charge compensated provided by two F^- ions positioned at interstitial sites adjacent to ²²⁹Th.

DOI： 10.1088/1367-2630/adce22

その他リンク： https://iopscience.iop.org/article/10.1088/1367-2630/adce22/pdf

Controlling 229Th isomeric state population in a VUV transparent crystal

Takahiro Hiraki, Koichi Okai, Michael Bartokos, Kjeld Beeks, Hiroyuki Fujimoto, Yuta Fukunaga, Hiromitsu Haba, Yoshitaka Kasamatsu, Shinji Kitao, Adrian Leitner, Takahiko Masuda, Ming Guan, Nobumoto Nagasawa, Ryoichiro Ogake, Martin Pimon, Martin Pressler, Noboru Sasao, Fabian Schaden, Thorsten Schumm, Makoto Seto, Yudai Shigekawa, Kotaro Shimizu, Tomas Sikorsky, Kenji Tamasaku, Sayuri Takatori, Tsukasa Watanabe, Atsushi Yamaguchi, Yoshitaka Yoda, Akihiro Yoshimi, Koji Yoshimura

Nature Communications 15 ( 1 ) 2024年7月

掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

Abstract

The radioisotope thorium-229 (²²⁹Th) is renowned for its extraordinarily low-energy, long-lived nuclear first-excited state. This isomeric state can be excited by vacuum ultraviolet (VUV) lasers and ²²⁹Th has been proposed as a reference transition for ultra-precise nuclear clocks. To assess the feasibility and performance of the nuclear clock concept, time-controlled excitation and depopulation of the ²²⁹Th isomer are imperative. Here we report the population of the ²²⁹Th isomeric state through resonant X-ray pumping and detection of the radiative decay in a VUV transparent ²²⁹Th-doped CaF₂ crystal. The decay half-life is measured to 447(25) s, with a transition wavelength of 148.18(42) nm and a radiative decay fraction consistent with unity. Furthermore, we report a new “X-ray quenching” effect which allows to de-populate the isomer on demand and effectively reduce the half-life. Such controlled quenching can be used to significantly speed up the interrogation cycle in future nuclear clock schemes.

DOI： 10.1038/s41467-024-49631-0

その他リンク： https://www.nature.com/articles/s41467-024-49631-0

Experimental apparatus for detection of radiative decay of $$^{229}$$Th isomer from Th-doped CaF$$_2$$

Takahiro Hiraki, Kjeld Beeks, Michael Bartokos, Hiroyuki Fujimoto, Yuta Fukunaga, Hiromitsu Haba, Yoshitaka Kasamatsu, Shinji Kitao, Adrian Leitner, Takahiko Masuda, Guan Ming, Nobumoto Nagasawa, Ryoichiro Ogake, Koichi Okai, Martin Pimon, Martin Pressler, Noboru Sasao, Fabian Schaden, Thorsten Schumm, Makoto Seto, Yudai Shigekawa, Koutaro Shimizu, Tomas Sikorsky, Kenji Tamasaku, Sayuri Takatori, Tsukasa Watanabe, Atsushi Yamaguchi, Yoshitaka Yoda, Akihiro Yoshimi, Koji Yoshimura

Hyperfine Interactions 245 ( 1 ) 2024年1月

Periodic superradiance in an Er:YSO crystal

Hideaki Hara, Junseok Han, Yasutaka Imai, Noboru Sasao, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura, Yuki Miyamoto

Physical Review Research 2024年1月

Vacuum Tltraviolet Search from Thorium-229 Isomer in Crystal Toward Solid-State Nuclear Clock

S. Takatori, Y. Fukunaga, M. Guan, T. Hiraki, T. Masuda, R. Ogake, K. Okai, N. Sasao, K. Shimizu, S. Uetake, A. Yoshimi, K. Yoshimura, M. Yoshimura, K. Tamasaku, Y. Kasamatsu, Y. Yasuda, K. Beeks, F. Schaden, T. Schumm, S. Kitao, M. Seto, H. Fujimoto, T. Watanabe, K. Konashi, M. Watanabe, H. Haba, Y. Shigekawa, A. Yamaguchi, N. Nagasawa, Y. Yoda

2023 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS) 2023年5月

Quantum dots as a probe of fundamental physics: deviation from exponential decay law 査読

Akihiro Yoshimi, Minoru Tanaka, Motohiko Yoshimura

The European Physical Journal D 76 113 2022年7月

Parity violating magnetization at neutrino pair emission using trivalent lanthanoid ions 査読

Hideaki Hara, Akihiro Yoshimi, Motohiko Yoshimura

Physical Review D 104 ( 11 ) 2021年12月

Estimation of radiative half-life of Th229m by half-life measurement of other nuclear excited states in Th229

Y. Shigekawa, A. Yamaguchi, K. Suzuki, H. Haba, T. Hiraki, H. Kikunaga, T. Masuda, S. Nishimura, N. Sasao, A. Yoshimi, K. Yoshimura

Physical Review C 104 ( 2 ) 2021年8月

Absolute X-ray energy measurement using a high-accuracy angle encoder

Takahiko Masuda, Tsukasa Watanabe, Kjeld Beeks, Hiroyuki Fujimoto, Takahiro Hiraki, Hiroyuki Kaino, Shinji Kitao, Yuki Miyamoto, Koichi Okai, Noboru Sasao, Makoto Seto, Thorsten Schumm, Yudai Shigekawa, Kenji Tamasaku, Satoshi Uetake, Atsushi Yamaguchi, Yoshitaka Yoda, Akihiro Yoshimi, Koji Yoshimura

Journal of Synchrotron Radiation 28 ( 1 ) 111 - 119 2021年1月

掲載種別：研究論文（学術雑誌）出版者・発行元：International Union of Crystallography ({IUCr})

<jats:p>This paper presents an absolute X-ray photon energy measurement method that uses a Bond diffractometer. The proposed system enables the prompt and rapid <jats:italic>in situ</jats:italic> measurement of photon energies over a wide energy range. The diffractometer uses a reference silicon single-crystal plate and a highly accurate angle encoder called SelfA. The performance of the system is evaluated by repeatedly measuring the energy of the first excited state of the potassium-40 nuclide. The excitation energy is determined as 29829.39 (6) eV, and this is one order of magnitude more accurate than the previous measurement. The estimated uncertainty of the photon energy measurement was 0.7 p.p.m. as a standard deviation and the maximum observed deviation was 2 p.p.m.</jats:p>

DOI： 10.1107/s1600577520014526

Neutrino mass spectroscopy using Er3+ ions placed at inversion center of host crystals

H. Hara, N. Sasao, A. Yoshimi, M. Yoshimura

arXiv:1910.14318v1 2019年10月

Energy response of X-rays under high flux conditions using a thin APD for the energy range of 6–33 keV 査読

T. Masuda, T. Hiraki, H. Kaino, S. Kishimoto, Y. Miyamoto, K. Okai, S. Okubo, R. Ozaki, N. Sasao, K. Suzuki, S. Uetake, A. Yoshimi, K. Yoshimura

Nucl. Instrum. Methods Phys. Res. A. 913 72 - 77 2019年

Geometry-dependent spectra and coherent-transient measurement of nearly degenerate four-wave mixing using two-photon resonance 査読

H. Hara, Y. Miyamoto, T. Hiraki, K. Imamura, T. Masuda, N. Sasao, S. Uetake, A. Yoshimi, K. Yoshimura, M. Yoshimura

J. Physics B 52 ( 23 ) 235402 2019年

Coherent two-photon emission from hydrogen molecules excited by counter-propagating laser pulses 査読

T. Hiraki, H. Hara, Y. Miyamoto, K. Imamura, T. Masuda, N. Sasao, S. Uetake, A. Yoshimi, K. Yoshimura, M. Yoshimura

J. Phys. B 52 ( 4 ) 045401 2019年

X-ray pumping of the 229Th nuclear clock isomer 査読

T. Masuda, A. Yoshimi, A. Fujieda, H. Fujimoto, H. Haba, H. Hara, T. Hiraki, H. Kaino, Y. Kasamatsu, S. Kitao, K. Konashi, Y. Miyamoto, K. Okai, S. Okubo, N. Sasao, M. Seto, T. Schumm, Y. Shigekawa, K. Suzuki, S. Stellmer, K. Tamasaku, S. Uetake, M. Watanabe, T. Watanabe, Y. Yasuda, A. Yamaguchi, Y. Yoda, T. Yokokita, M. Yoshimura, K. Yoshimura

Nature 573 ( 7773 ) 238 - 242 2019年

Development of co-located 129Xe and 131Xe nuclear spin masers with external feedback scheme 査読

T. Sato, Y. Ichikawa, S. Kojima, C. Funayama, S. Tanaka, T. Inoue, A. Uchiyama, A. Gladkov, A. Takamine, Y. Sakamoto, Y. Ohtomo, C. Hirao, M. Chikamori, E. Hikota, T. Suzuki, M. Tsuchiya, T. Furukawa, A. Yoshimi, C. P. Bidinosti, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, N. Yoshinaga, Y. Sakemi, K. Asahi

Physics Letters, Section A: General, Atomic and Solid State Physics 382 ( 8 ) 588 - 594 2018年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier B.V.

We report on the operation of co-located 129Xe and 131Xe nuclear spin masers with an external feedback scheme, and discuss the use of 131Xe as a comagnetometer in measurements of the 129Xe spin precession frequency. By applying a correction based on the observed change in the 131Xe frequency, the frequency instability due to magnetic field and cell temperature drifts are eliminated by two orders of magnitude. The frequency precision of 6.2 μHz is obtained for a 104 s averaging time, suggesting the possibility of future improvement to ≈ 1 nHz by improving the signal-to-noise ratio of the observation.

DOI： 10.1016/j.physleta.2017.12.003

Nuclear resonant scattering experiment with fast time response: Photonuclear excitation of Hg 201 査読

A. Yoshimi, H. Hara, T. Hiraki, Y. Kasamatsu, S. Kitao, Y. Kobayashi, K. Konashi, R. Masuda, T. Masuda, Y. Miyamoto, K. Okai, S. Okubo, R. Ozaki, N. Sasao, O. Sato, M. Seto, T. Schumm, Y. Shigekawa, S. Stellmer, K. Suzuki, S. Uetake, M. Watanabe, A. Yamaguchi, Y. Yasuda, Y. Yoda, K. Yoshimura, M. Yoshimura

Physical Review C 97 ( 2 ) 024607 2018年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Physical Society

Nuclear resonant excitation and detection of its decay signal for the 26.27-keV level of Hg201 is demonstrated with high-brilliance synchrotron radiation (SR) and a fast x-ray detector system. This SR-based photonuclear excitation scheme, known as nuclear resonant scattering (NRS) in the field of materials science, is also useful for investigating nuclear properties, such as the half-lives and radiative widths of excited nuclear levels. To date, because of the limited time response of the x-ray detector, the nuclear levels to which this method could be applied have been limited to the one whose half-lives are longer than ∼1 ns. The faster time response of the NRS measurement makes possible NRS experiments on nuclear levels with much shorter half-lives. We have fabricated an x-ray detector system that has a time resolution of 56 ps and a shorter tail function than that reported previously. With the implemented detector system, the NRS signal of the 26.27-keV state of Hg201 could be clearly discriminated from the electronic scattering signal at an elapsed time of 1 ns after the SR pulse. The half-life of the state was determined as 629 ± 18 ps, which has better precision by a factor of three compared with that reported to date obtained from nuclear decay spectroscopy.

DOI： 10.1103/PhysRevC.97.024607

Vibrational excitation of hydrogen molecules by two-photon absorption and third-harmonic generation 査読

Yuki Miyamoto, Hideaki Hara, Takahiro Hiraki, Takahiko Masuda, Noboru Sasao, Satoshi Uetake, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura

JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 51 ( 1 ) 015401 2018年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

We report the coherent excitation of the vibrational state of hydrogen molecules by two-photon absorption and the resultant third-harmonic generation (THG). Parahydrogen molecules cooled by liquid nitrogen are irradiated by mid-infrared nanosecond pulses at 4.8 mu m with a nearly Fourier-transform-limited linewidth. The first excited vibrational state of parahydrogen is populated by two-photon absorption of the mid-infrared photons. Because of the narrow linewidth of the mid-infrared pulses, coherence between the ground and excited states is sufficient to induce higher-order processes. Near-infrared photons from the THG are observed at 1.6 mu m. The dependence of the intensity of the near-infrared radiation on mid-infrared pulse energy, target pressure, and cell length is determined. We used a simple formula for THG with consideration of realistic experimental conditions to explain the observed results.

DOI： 10.1088/1361-6455/aa9782

Frequency dependence of coherently amplified two-photon emission from hydrogen molecules 査読

Hideaki Hara, Yuki Miyamoto, Takahiro Hiraki, Takahiko Masuda, Noboru Sasao, Satoshi Uetake, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura

PHYSICAL REVIEW A 96 ( 6 ) 063827 2017年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYSICAL SOC

We investigate how the efficiency of coherently amplified two-photon emission depends on the frequency of one of the two emitted photons, namely the signal photon. This is done over the wavelength range of 5.048-10.21 mu m by using the vibrational transition of parahydrogen. The efficiency increases with the frequency of the signal photon. Considering experimental errors, our results are consistent with the theoretical prediction for the present experimental conditions. This study is an experimental demonstration of the frequency dependence of coherently amplified two-photon emission, and also presents its potential as a light source.

DOI： 10.1103/PhysRevA.96.063827

A new method of creating high intensity neutron source 査読

T. Masuda, A. Yoshimi, M. Yoshimura

INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 26 ( 11 ) 1750076 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

We propose a new scheme of producing an intense neutron beam whose yields may exceed those of the existing facilities by a few to several orders of magnitude in the sub-eV region. This scheme employs a MeV gamma beam extracted from circulating quantum ions, which has been recently proposed. The gamma beam is directed to a deuteron target and the photo-disintegration process generates a neutron beam. The calculated neutron energy spectrum is nearly flat down to the neV range, and thus there exists a possibility to utilize a good quality of neutrons especially in sub-eV energy region without using a moderator.

DOI： 10.1142/S0218301317500768

Fast x-ray detector system with simultaneous measurement of timing and energy for a single photon 査読

T. Masuda, S. Okubo, H. Hara, T. Hiraki, S. Kitao, Y. Miyamoto, K. Okai, R. Ozaki, N. Sasao, M. Seto, S. Uetake, A. Yamaguchi, Y. Yoda, A. Yoshimi, K. Yoshimura

REVIEW OF SCIENTIFIC INSTRUMENTS 88 ( 6 ) 063105 2017年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER INST PHYSICS

We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The system is able to acquire both timing and energy of a single X-ray photon simultaneously in a high rate condition, 106 counts per second for one Si-APD. The performance of the system was investigated in SPring-8, a synchrotron radiation facility in Japan. Good time resolution of 120 ps (FWHM) was achieved with a slight tail distribution in the time spectrum by a level of 10(-9) at 1 ns apart from the peak. Using this system, we successfully observed the NRS from the 26.27-keV level of mercury-201, which has a half-life of 630(50) ps. We also demonstrated the reduction of background events caused by radioactive decays in a radioactive sample by discriminating photon energy. Published by AIP Publishing.

DOI： 10.1063/1.4989405

Development Of 131Xe Co-magnetometry For Xe Atomic EDM Search

Tomoya Sato, Yuichi Ichikawa, Shuichiro Kojima, Chikako Funayama, Shunya Tanaka, Yu Sakamoto, Yuichi Ohtomo, Chika Hirao, Masatoshi Chikamori, Eri Hikota, Takeshi Furukawa, Akihiro Yoshimi, Christopher Paul Bidinosti, Takashi Ino, Hideki Ueno, Yukari Matsuo, Takeshi Fukuyama, Koichiro Asahi

Proceedings of The 26th International Nuclear Physics Conference — PoS(INPC2016) 2017年5月

Vibrational Two-Photon Emission from Coherently Excited Solid Parahydrogen 査読

Yuki Miyamoto, Hideaki Hara, Takahiko Masuda, Noboru Sasao, Satoshi Uetake, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura

JOURNAL OF PHYSICAL CHEMISTRY A 121 ( 20 ) 3943 - 3951 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

We report the observation of two-photon emission from a coherently excited vibrational state of solid parahydrogen, which is also a known quantum solid. Coherence between the ground and the excited states is prepared by stimulated Raman scattering using two visible laser pulses. The two-photon emission is triggered by another mid-infrared laser pulse. It was observed that the two-photon emission persists even when the trigger pulse is injected long after the excitation. This is due to the long decoherence time of the vibrational states of solid parahydrogen. It is found that the emission intensity increases even after the excitation pulses pass through the target completely. This coherence development is highly suppressed at high target temperatures and high residual orthohydrogen concentrations. Effects of target annealing and laser-induced damage on the target are also observed.

DOI： 10.1021/acs.jpca.7b02011

High-precision quadrupole moment reveals significant intruder component in Al-33(13)20 ground state

H. Heylen, M. De Rydt, G. Neyens, M. L. Bissell, L. Caceres, R. Chevrier, J. M. Daugas, Y. Ichikawa, Y. Ishibashi, O. Kamalou, T. J. Mertzimekis, P. Morel, J. Papuga, A. Poves, M. M. Rajabali, C. Stodel, J. C. Thomas, H. Ueno, Y. Utsuno, N. Yoshida, A. Yoshimi

PHYSICAL REVIEW C 94 ( 3 ) 2016年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYSICAL SOC

The electric quadrupole moment of the Al-33(13)20 ground state, located at the border of the island of inversion, was obtained using continuous-beam beta-detected nuclear quadrupole resonance (beta-NQR). From the measured quadrupole coupling constant nu(Q) = 2.31(4) MHz in an alpha-Al2O3 crystal, a precise value for the electric quadrupole moment is extracted: vertical bar Q(s) (Al-33)vertical bar = 141(3) mb. A comparison with large-scale shell model calculations shows that Al-33 has at least 50% intruder configurations in the ground state wave function, favoring the excitation of two neutrons across the N = 20 shell gap. Al-33 therefore clearly marks the gradual transition north of the deformed Na and Mg nuclei towards the normal Z >= 14 isotopes.

DOI： 10.1103/PhysRevC.94.034312

Frequency characteristics of nuclear spin oscillator with an artificial feedback toward search for 129Xe atomic electric dipole moment 査読

Takeshi Inoue, Takeshi Furukawa, Akihiro Yoshimi, Tsubasa Nanao, Masatoshi Chikamori, Kunifumi Suzuki, Hironori Hayashi, Hirokazu Miyatake, Yuichi Ichikawa, Masato Tsuchiya, Naoto Hatakeyama, Sota Kagami, Makoto Uchida, Hideki Ueno, Yukari Matsuo, Takeshi Fukuyama, Koichiro Asahi

The European Physical Journal D 70 ( 6 ) 129 2016年6月

Simultaneous Measurements of Superradiance at Multiple Wavelength from Helium Excited States: II. Analysis 査読

Ohae Chiaki, Harries James R, Iwayama Hiroshi, Kawaguchi Kentarou, Kuma Susumu, Miyamoto Yuki, Nagasono Mitsuru, Nakajima Kyo, Nakano Itsuo, Shigemasa Eiji, Sasao Noboru, Uetake Satoshi, Wakabayashi Tomonari, Yoshimi Akihiro, Yoshimura Koji, Yoshimura Motohiko

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 85 ( 3 ) 2016年3月

20pAX-6 中性子過剰核^<39>Sの核磁気モーメント測定

石橋陽子, 市川雄一, 高峰愛子, 今村慧, 藤田朋美, 佐藤智哉, 旭耕一郎, 江上魁, 舟山智歌子, 川口高史, 小島修一郎, 西坂太志, 大友祐一, 小沢顕, 富永大樹, 山崎展樹, 吉見彰洋, 上野秀樹

日本物理学会講演概要集 71 332 - 332 2016年

Recent progress of SPAN towards neutrino mass spectroscopy 査読

Masuda T, Hara H, Miyamoto Y, Sasao N, Tanaka M, Uetake S, Yoshimi A, Yoshimura K, Yoshimura M

Journal of Physics: Conference Series 718 ( 6 ) 2016年

固体パラ水素振動準位を用いたコヒーレント二光子放出の観測

宮本祐樹, 原秀明, 増田孝彦, 植竹智, 笹尾登, 吉見彰洋, 吉村浩司, 吉村太彦

日本物理学会講演概要集 71 577 - 577 2016年

記述言語：日本語出版者・発行元：一般社団法人日本物理学会

<p>二光子吸収は良く知られた二光子過程であるが、逆過程である二光子放出の、特に固体中での報告は少ない。本研究では、固体パラ水素の振動準位をラマン過程によりコヒーレントに励起、さらに中赤外レーザーを照射することで二光子放出のレートを増幅し、観測することに成功した。固体パラ水素の振動状態は長いデコヒーレンス時間を持つため、中赤外レーザーを励起から100ns以上後に入射しても二光子放出が観測された。</p>

DOI： 10.11316/jpsgaiyo.71.2.0_577

22aAX-11 ^<129>Xe/^<131>Xe共存核スピンメーザーの周波数特性

小島修一郎, 佐藤智哉, 市川雄一, 田中俊也, 舟山智歌子, 坂本雄, 大友祐一, 平尾千佳, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 71 436 - 436 2016年

22aAX-10 異核種共存セルにおけるスピン偏極生成・緩和機構

舟山智歌子, 佐藤智哉, 市川雄一, 小島修一郎, 田中俊也, 坂本雄, 大友祐一, 平尾千佳, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 71 435 - 435 2016年

22aAX-12 異核種共存核スピンメーザーを用いたEDM測定実験

佐藤智哉, 市川雄一, 小島修一郎, 舟山智歌子, 田中俊也, 坂本雄, 大友祐一, 平尾千佳, 近森正敏, 彦田絵里, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 71 437 - 437 2016年

22aAX-4 フランシウム原子を用いた電子EDM探索に向けたルビジウム磁力計の研究

内山愛子, 井上壮志, 青木隆宏, 伊藤沙希, 加藤浩, 川村広和, 坂本幸祐, 早水友洋, 原田健一, 青木貴稔, 旭耕一郎, 吉見彰洋, 酒見泰寛

日本物理学会講演概要集 71 433 - 433 2016年

Performance assessment of a new laser system for efficient spin exchange optical pumping in a spin maser measurement of 129Xe EDM

C. Funayama, T. Furukawa, T. Sato, Y. Ichikawa, Y. Ohtomo, Y. Sakamoto, S. Kojima, T. Suzuki, C. Hirao, M. Chikamori, E. Hikota, M. Tsuchiya, A. Yoshimi, C. P. Bidinosti, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

Hyperfine Interactions 236 ( 1-3 ) 59 - 64 2015年11月

Experimental search for the electron electric dipole moment with laser cooled francium atoms

T. Inoue, S. Ando, T. Aoki, H. Arikawa, S. Ezure, K. Harada, T. Hayamizu, T. Ishikawa, M. Itoh, K. Kato, H. Kawamura, A. Uchiyama, T. Aoki, K. Asahi, T. Furukawa, A. Hatakeyama, K. Hatanaka, K. Imai, T. Murakami, H. S. Nataraj, T. Sato, Y. Shimizu, T. Wakasa, H. P. Yoshida, A. Yoshimi, Y. Sakemi

Hyperfine Interactions 231 ( 1-3 ) 157 - 162 2015年4月

EDM measurement in 129Xe atom using dual active feedback nuclear spin maser

T. Sato, Y. Ichikawa, Y. Ohtomo, Y. Sakamoto, S. Kojima, C. Funayama, T. Suzuki, M. Chikamori, E. Hikota, M. Tsuchiya, T. Furukawa, A. Yoshimi, C. P. Bidinosti, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

Hyperfine Interactions 230 ( 1-3 ) 147 - 153 2015年4月

26aSF-5 冷却フランシウム原子によるEDM探索技術の開発

酒見泰寛, 青木隆宏, 原田健一, 早水友洋, 井上壮志, 伊藤正俊, 伊藤沙希, 加藤浩, 川村広和, 坂本幸祐, 内山愛子, 久野純治, 青木貴稔, 畠山温, 畑中吉治, 若狭智嗣, 高橋義朗, 旭耕一郎, 吉見彰洋

日本物理学会講演概要集 70 251 - 251 2015年

129Xe EDM Search Experiment Using Active Nuclear Spin Maser 査読

JPS Conf. Proc. 6 020031 2015年

Externally triggered coherent two-photon emission from hydrogen molecules 査読

Miyamoto Y, Hara H, Masuda T, Sasao N, Tanaka M, Uetake S, Yoshimi A, Yoshimura K, Yoshimura M

Progress of Theoretical and Experimental Physics 2015 ( 8 ) 2015年

Rate amplification of the two photon emission from para-hydrogen toward the neutrino mass measurement 査読

Masuda T, Hara H, Miyamoto Y, Kuma S, Nakano I, Ohae C, Sasao N, Tanaka M, Uetake S, Yoshimi A, Yoshimura K, Yoshimura M

Hyperfine Interactions 236 ( 1-3 ) 73 - 77 2015年

Development of high-homogeneity magnetic field coil for 129Xe EDM experiment 査読

Y. Sakamoto, C. P. Bidinosti, Y. Ichikawa, T. Sato, Y. Ohtomo, S. Kojima, C. Funayama, T. Suzuki, M. Tsuchiya, T. Furukawa, A. Yoshimi, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

Hyp. Int. 230 ( 1-3 ) 141 - 146 2015年

Spin-aligned RI beams and g-factor measurements 査読

JPS Conf. Proc. 6 030004 2015年

Double-cell Geometry For 129Xe/3He Co-magnetometry 査読

JPS Conf. Proc. 6 030067 - 030067 2015年

Two Pion versus σ-Meson Exchange Potentials

Sachiko Oshima, Takehisa Fujita, Naohiro K, a, Akihiro Yoshimi

Journal of Modern Physics 06 ( 07 ) 927 - 936 2015年

21aCE-1 ^<129>Xe/^3He同時メーザー発振のためのポンピングレーザーシステムの開発

舟山智歌子, 古川武, 佐藤智哉, 市川雄一, 大友祐一, 坂本雄, 小島修一郎, 平尾千佳, 菅野雄輝, 小峰太郎, 鈴木貴大, 近森正敏, 彦田絵里, 土屋真人, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 70 244 - 244 2015年

21aCE-3 ダブルセルにおける^<129>Xe/^3He 核スピンメーザーの周波数特性

小島修一郎, 佐藤智哉, 市川雄一, 大友祐一, 坂本雄, 舟山智歌子, 平尾千佳, 菅野雄揮, 小峰太郎, 鈴木貴大, 近森正敏, 彦田絵里, 土屋真人, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 70 246 - 246 2015年

21aCE-4 ^3He 共存磁力計の導入による^<129>Xe原子EDM 測定実験IV

佐藤智哉, 市川雄一, 大友祐一, 坂本雄, 小島修一郎, 舟山智歌子, 平尾千佳, 菅野雄輝, 小峰太郎, 鈴木貴大, 近森正敏, 彦田絵里, 土屋真人, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 70 247 - 247 2015年

22pAG-7 水素分子振動準位間のコヒーレント2光子放出III

植竹智, 原秀明, 増田孝彦, 宮本祐樹, 中野逸夫, 笹尾登, 田中実, 吉見彰洋, 吉村浩司, 吉村太彦

日本物理学会講演概要集 70 668 - 668 2015年

22aDF-11 SPAN(原子を用いたニュートリノ質量分光実験)のためのマクロコヒーレント増幅機構の詳細研究II

原秀明, 増田孝彦, 宮本祐樹, 中野逸夫, 笹尾登, 田中実, 植竹智, 吉見彰洋, 吉村浩司, 吉村太彦

日本物理学会講演概要集 70 86 - 86 2015年

21aCE-2 一様磁場環境下での^<129>Xe/^3He 同時メーザー発振

坂本雄, Bidinosti C. P., 市川雄一, 佐藤智哉, 大友祐一, 小島修一郎, 舟山智歌子, 鈴木貴大, 平尾千佳, 菅野雄揮, 小峰太郎, 土屋真人, 古川武, 吉見彰洋, 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 70 245 - 245 2015年

21aCE-6 フランシウムを用いた電子EDM探索に向けたルビジウム磁力計の開発

内山愛子, 井上壮志, 青木隆宏, 有川裕士, 安藤峻, 石川泰佑, 伊藤正俊, 加藤浩, 川村広和, 坂本幸祐, 早水友洋, 原田健一, 青木貴稔, 旭耕一郎, 吉見彰洋, 酒見泰寛

日本物理学会講演概要集 70 249 - 249 2015年

26aSF-6 ^<129>Xe/^3He二核種スピンメーザーを用いた周波数精密測定における周波数不定性

佐藤智哉, 市川雄一, 小島修一郎, 舟山智歌子, 坂本雄, 大友祐一, 平尾千佳, 近森正敏, 彦田絵里, 古川武, 吉見彰洋, Bidinosti C. P., 猪野隆, 上野秀樹, 松尾由賀利, 福山武志, 旭耕一郎

日本物理学会講演概要集 70 252 - 252 2015年

Development of magnetometer based on the Nonlinear Magneto-Optical Rotation effect toward the measurement of the electron electric dipole moment 査読

JPS Conf. Proc. 6 030070 2015年

Production of Ba Metastable State via Superradiance 査読

Ohae Chiaki, Fukumi Atsushi, Kuma Susumu, Miyamoto Yuki, Nakajima Kyo, Nakano Itsuo, Nanjo Hajime, Sasao Noboru, Uetake Satoshi, Wakabayashi Tomonari, Yoshimi Akihiro, Yoshimura Koji, Yoshimura Motohiko

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 83 ( 4 ) 2014年4月

Search for electric dipole moment in Xe-129 atom using a nuclear spin oscillator 査読

K. Asahi, Y. Ichikawa, M. Chikamori, Y. Ohtomo, E. Hikota, T. Suzuki, T. Inoue, T. Furukawa, A. Yoshimi, K. Suzuki, T. Nanao, H. Miyatake, M. Tsuchiya, N. Yoshida, H. Shirai, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama

PHYSICS OF PARTICLES AND NUCLEI 45 ( 1 ) 199 - 201 2014年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MAIK NAUKA/INTERPERIODICA/SPRINGER

We aim to measure the electric dipole moment (EDM) of a diamagnetic atom Xe-129 using an optical-detection nuclear spin maser technique. The relation of EDM in a diamagnetic atom to nuclear Schiff moment and fundamental sources generating it is discussed, and the present status for the development of our experimental setup is presented.

DOI： 10.1134/S1063779614010080

Observation of coherent two-photon emission from the first vibrationally excited state of hydrogen molecules 査読

Miyamoto Y, Hara H, Kuma S, Masuda T, Nakano I, Ohae C, Sasao N, Tanaka M, Uetake S, Yoshimi A, Yoshimura K, Yoshimura M

Progress of Theoretical and Experimental Physics 2014 ( 11 ) 2014年

Active nuclear spin maser oscillation with double cell 査読

E. Hikota, M. Chikamori, Y. Ichikawa, Y. Ohtomo, Y. Sakamoto, T. Suzuki, C. P. Bidinosti, T. Inoue, T. Furukawa, A. Yoshimi, K. Suzuki, T. Nanao, H. Miyatake, M. Tsuchiya, N. Yoshida, H. Shirai, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 2 66 05005 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：E D P SCIENCES

Uncertainty in the frequency precision of the planned experiment to search for a Xe-129 atomic electric dipole moment is dominated by drifts in the frequency shift due to contact interaction of Xe-129 with polarized Rb valence electrons. In order to suppress the frequency shift, a double-cell geometry has been adopted for the confinement of Xe-129 gas. A new process has been identified to take part in the optical detection of spin precession. The parameters controlling the oscillation of the maser in this new double-cell arrangement were optimized As a result, the frequency shift has been reduced by a factor of 10 or more from the former single-cell geometry.

DOI： 10.1051/epjconf/20146605005

Search for electric dipole moment in Xe-129 atom using active nuclear spin maser 査読

Y. Ichikawa, M. Chikamori, Y. Ohtomo, E. Hikota, Y. Sakamoto, T. Suzuki, C. P. Bidinosti, T. Inoue, T. Furukawa, A. Yoshimi, K. Suzuki, T. Nanao, H. Miyatake, M. Tsuchiya, N. Yoshida, H. Shirai, T. Ino, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 2 66 05007 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：E D P SCIENCES

An experimental search for an electric dipole moment in the diamagnetic atom Xe-129 is in progress through the precision measurement of spin precession frequency using an active nuclear spin maser. A He-3 comagnetometer has been incorporated into the active spin maser system in order to cancel out the long-term drifts in the external magnetic field. Also, a double-cell geometry has been adopted in order to suppress the frequency shifts due to interaction with polarized Rb atoms. The first EDM measurement with the Xe-129 active spin maser and the He-3 comagnetometer has been conducted.

DOI： 10.1051/epjconf/20146605007

Spin-aligned RI beams via two-step fragmentation reactions 査読

Y. Ichikawa, H. Ueno, Y. Ishii, T. Furukawa, A. Yoshimi, D. Kameda, H. Watanabe, N. Aoi, K. Asahi, D. L. Balabanski, R. Chevrier, J. M. Daugas, N. Fukuda, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, T. Kubo, T. Nanao, T. Ohnishi, K. Suzuki, M. Tsuchiya, H. Takeda, M. M. Rajabali

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 317 769 - 773 2013年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

A method to produce spin-aligned rare isotope (RI) beams has been developed, where a scheme of two-step projectile fragmentation to produce the RI of interest with high spin alignment and a technique of momentum-dispersion matching are combined. Effectiveness of the present method was demonstrated in an experiment at the RIKEN RIBF, where an RI beam of Al-32 with spin alignment of 8(1)% was successfully produced from a primary beam of Ca-48, via an intermediate RI of Al-33. Figure of merit of the present method was found to be more than 50 times greater than that of the conventional method employing single-step projectile fragmentation. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nimb.2013.04.071

Development of a new device control system for β-NMR experiments

N. Yoshida, H. Ueno, A. Yoshimi, Y. Ishibashi, Y. Ichikawa, Y. Abe, K. Asahi, M. Chikamori, T. Fujita, T. Furukawa, E. Hikota, D. Nagae, Y. Ohtomo, Y. Saito, H. Shirai, T. Suzuki, X.F. Yang

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 317 705 - 709 2013年12月

Development of an adiabatic field rotation system to measure spin polarization of unstable nuclei

Y. Ishibashi, N. Yoshida, H. Ueno, A. Yoshimi, Y. Ichikawa, Y. Abe, K. Asahi, M. Chikamori, T. Fujita, T. Furukawa, E. Hikota, D. Nagae, Y. Ohtomo, Y. Saito, H. Shirai, T. Suzuki, X.F. Yang, N. Sakamoto

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 317 714 - 716 2013年12月

Coherence decay measurement of v=2 vibrons in solid parahydrogen 査読

Susumu Kuma, Yuki Miyamoto, Kyo Nakajima, Atsushi Fukumi, Kentarou Kawaguchi, Itsuo Nakano, Noboru Sasao, Minoru Tanaka, Jian Tang, Takashi Taniguchi, Satoshi Uetake, Tomonari Wakabayashi, Akihiro Yoshimi, Motohiko Yoshimura

JOURNAL OF CHEMICAL PHYSICS 138 ( 2 ) 024507 2013年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER INST PHYSICS

The coherence decay of the v = 2 vibrational state (vibrons) of solid parahydrogen was measured via time-resolved coherent anti-Stokes Raman spectroscopy. We found that the decay curve has a non-exponential time profile in the time scale of 200 ns at a low temperature below 5 K and a low orthohydrogen impurity concentration (similar to 0.01%). This behavior, as also observed in the case of the v = 1 vibrons, represents a signature of band structure of the v = 2 state in the solid phase. The maximum coherence decay time of 50 ns in an exponential part was achieved, which shows excellence of the v = 2 state for coherent processes. We also found that finite temperatures, orthohydrogen impurities, and other structural inhomogeneity accelerate the decay, hiding the non-exponential feature of the vibron band. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773893]

DOI： 10.1063/1.4773893

Nuclear moments of mu-second isomeric fragments at BigRIPS 査読

R. Chevrier, J. M. Daugas, L. Gaudefroy, M. Hass, H. Haas, H. Ueno, N. Aoi, N. Fukuda, Y. Ichikawa, N. Inabe, M. Ishihara, D. Kameda, T. Kubo, T. Ohnishi, H. Takeda, H. Watanabe, A. Yoshimi, K. Asahi, T. Furukawa, H. Hayashi, H. Iijima, T. Inoue, Y. Ishii, T. Nanao, K. Suzuki, M. Tsuchiya, D. L. Balabanski, G. Georgiev, S. Cootenier, G. Neyens, M. Rajabali

FRENCH-JAPANESE SYMPOSIUM ON NUCLEAR STRUCTURE PROBLEMS: ORGANIZED IN THE FRAMEWORK OF FJNSP LIA AND EFES 33 - 39 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

The measurement of nuclear moments of a mu-second isomeric state have been successfully performed using the RIKEN Radioactive Ion Beam Facility. The Time Dependent Perturbed Angular Distribution technique was applied on the 43 S isomeric state produced by the fragmentation of a Ca-48 beam and selected with the BigRIPS spectrometer. Following the measurement of the known g-factor of the isomer the quadrupole moment of this state was measured. Its spectroscopic quadrupole moment vertical bar Q(S)vertical bar = 23( 3) efm(2) agreed with both shell model and beyond mean field calculations.

Production of spin-aligned RI beams via the two-step fragmentation reaction 査読

H. Ueno, Y. Ichikawa, Y. Ishii, T. Furukawa, A. Yoshimi, D. Kameda, H. Watanabe, N. Aoi, K. Asahi, D. L. Balabanski, R. Chevrier, J. M. Daugas, N. Fukuda, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, T. Kubo, T. Nanao, T. Ohnishi, K. Suzuki, M. Tsuchiya, H. Takeda, M. M. Rajabali

FRENCH-JAPANESE SYMPOSIUM ON NUCLEAR STRUCTURE PROBLEMS: ORGANIZED IN THE FRAMEWORK OF FJNSP LIA AND EFES 40 - 45 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

Based on the technique of fragmentation-induced spin polarization combined with the beta-NMR method, we have conducted a series of ground-state nuclear-moment measurements in a region of light neutron-rich nuclei at RIKEN. The research has recently been extended also at GANIL. The ground-state studies will be further enhanced by the upgrade of RIPS proposed in the RIBF Phase-II program. Also, utilizing the technique of fragmentation-induced spin-orientation, nuclear-moment measurements of isomeric state were conducted. Remarkably, we have recently developed a method to produce highly spin-aligned RI beams in a new promising scheme. The method was first examined using BigRIPS, where a highly spin-aligned isomeric Al-32m beam was successfully produced through the two-step projectile fragmentation reaction.

Nuclear spin maser and experimental search for Xe-129 atomic EDM 査読

T. Inoue, T. Furukawa, A. Yoshimi, Y. Ichikawa, M. Chikamori, Y. Ohtomo, M. Tsuchiya, N. Yoshida, H. Shirai, M. Uchida, K. Suzuki, T. Nanao, H. Miyatake, H. Ueno, Y. Matsuo, T. Fukuyama, K. Asahi

Hyp. Int. 220 59 - 63 2013年

Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique 査読

Hyperfine. Interact. 220 47 - 51 2013年

Production of spin-controlled rare isotope beams 査読

Yuichi Ichikawa, Hideki Ueno, Yuji Ishii, Takeshi Furukawa, Akihiro Yoshimi, Daisuke Kameda, Hiroshi Watanabe, Nori Aoi, Koichiro Asahi, Dimiter L. Balabanski, Raphael Chevrier, Jean-Michel Daugas, Naoki Fukuda, Georgi Georgiev, Hironori Hayashi, Hiroaki Iijima, Naoto Inabe, Takeshi Inoue, Masayasu Ishihara, Toshiyuki Kubo, Tsubasa Nanao, Tetsuya Ohnishi, Kunifumi Suzuki, Masato Tsuchiya, Hiroyuki Takeda, Mustafa M. Rajabali

NATURE PHYSICS 8 ( 12 ) 918 - 922 2012年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

The degree of freedom of spin in quantum systems serves as an unparalleled laboratory where intriguing quantum physical properties can be observed, and the ability to control spin is a powerful tool in physics research. We propose a method for controlling spin in a system of rare isotopes which takes advantage of the mechanism of the projectile fragmentation reaction combined with the momentum-dispersion matching technique. The present method was verified in an experiment at the RIKEN RI Beam Factory, in which a degree of alignment of 8% was achieved for the spin of a rare isotope Al-32. The figure of merit for the present method was found to be greater than that of the conventional method by a factor of more than 50.

DOI： 10.1038/NPHYS2457

Observation of new microsecond isomers among fission products from in-flight fission of 345 MeV/nucleon U-238 査読

D. Kameda, T. Kubo, T. Ohnishi, K. Kusaka, A. Yoshida, K. Yoshida, M. Ohtake, N. Fukuda, H. Takeda, K. Tanaka, N. Inabe, Y. Yanagisawa, Y. Gono, H. Watanabe, H. Otsu, H. Baba, T. Ichihara, Y. Yamaguchi, M. Takechi, S. Nishimura, H. Ueno, A. Yoshimi, H. Sakurai, T. Motobayashi, T. Nakao, Y. Mizoi, M. Matsushita, K. Ieki, N. Kobayashi, K. Tanaka, Y. Kawada, N. Tanaka, S. Deguchi, Y. Satou, Y. Kondo, T. Nakamura, K. Yoshinaga, C. Ishii, H. Yoshii, Y. Miyashita, N. Uematsu, Y. Shiraki, T. Sumikama, J. Chiba, E. Ideguchi, A. Saito, T. Yamaguchi, I. Hachiuma, T. Suzuki, T. Moriguchi, A. Ozawa, T. Ohtsubo, M. A. Famiano, H. Geissel, A. S. Nettleton, O. B. Tarasov, D. Bazin, B. M. Sherrill, S. L. Manikonda, J. A. Nolen

PHYSICAL REVIEW C 86 ( 5 ) 054319 2012年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYSICAL SOC

A search for isomeric gamma decays among fission fragments from 345 MeV/nucleon U-238 has been performed at the RIKEN Nishina Center RI Beam Factory. Fission fragments were selected and identified using the superconducting in-flight separator BigRIPS and were implanted in an aluminum stopper. Delayed gamma rays were detected using three clover-type high-purity germanium detectors located at the focal plane within a time window of 20 mu s following the implantation. We identified a total of 54 microsecond isomers with half-lives of similar to 0.1-10 mu s, including the discovery of 18 new isomers in very neutron-rich nuclei: Ti-59(m), As-90(m), Se-92(m), Se-93(m), Br-94(m), Br-95(m), Br-96(m), Rb-97(m), Nb-108(m), Mo-109(m), Ru-117(m), Ru-119(m), Rh-120(m), Rh-122(m), Pd-121(m), Pd-124(m), Ag-124(m), and Ag-126(m), and obtained a wealth of spectroscopic information such as half-lives, gamma-ray energies, gamma-ray relative intensities, and gamma gamma coincidences over a wide range of neutron-rich exotic nuclei. Proposed level schemes are presented for Ti-59(m), Ga-82(m), Br-92(m), Br-94(m), Br-95(m), Rb-97(m), Rb-98(m), Nb-108(m), Zr-108(m), Mo-109(m), Ru-117(m), Ru-119(m), Rh-120(m), Rh-122(m), Pd-121(m), Ag-124(m), and Ag-125(m), based on the obtained spectroscopic information and the systematics in neighboring nuclei. The nature of the nuclear isomerism is discussed in relation to the evolution of nuclear structure.

DOI： 10.1103/PhysRevC.86.054319

Erosion of N=20 shell in Al-33 investigated through the ground-state electric quadrupole moment 査読

K. Shimada, H. Ueno, G. Neyens, K. Asahi, D. L. Balabanski, J. M. Daugas, M. Depuydt, M. De Rydt, L. Gaudefroy, S. Grevy, Y. Hasama, Y. Ichikawa, D. Kameda, P. Morel, T. Nagatomo, L. Perrot, Ch Stodel, J. -C. Thomas, Y. Utsuno, W. Vanderheijden, N. Vermeulen, P. Vingerhoets, E. Yagi, K. Yoshida, A. Yoshimi

PHYSICS LETTERS B 714 ( 2-5 ) 246 - 250 2012年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Electric quadrupole moment Q of the Al-33 ground state has been measured by means of beta-NMR spectroscopy using a spin-polarized Al-33 beam produced in a projectile fragmentation reaction. The obtained Q moment, vertical bar Q(exp)(Al-33)vertical bar = 132(16) emb, shows a significant excess from the prediction of shell model calculations within the sd shell. The result indicates sizable admixing of pf intruder configurations in the ground state, demonstrating that the N = 20 shell closure certainly erodes in Al-33, a nucleus located on the border of the island of inversion. Comparison was made with predictions of the Monte Carlo shell model, and also a particle-vibration coupling model treating the neutron pairing correlations in the ground state of Al-33. Again, a significant admixture of pf intruder configurations to the Al-33 ground state was needed in both theoretical approaches to explain the observed large Q. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physletb.2012.07.030

Low-frequency Xe-129 nuclear spin oscillator with optical spin detection 査読

A. Yoshimi, T. Inoue, T. Furukawa, T. Nanao, K. Suzuki, M. Chikamori, M. Tsuchiya, H. Hayashi, M. Uchida, N. Hatakeyama, S. Kagami, Y. Ichikawa, H. Miyatake, K. Asahi

PHYSICS LETTERS A 376 ( 24-25 ) 1924 - 1929 2012年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

We have constructed a Xe-129 nuclear spin oscillator which executes a self-sustained oscillation through an external feedback loop with optical detection of nuclear spin. The oscillator is capable of operating at frequencies much lower than the conventional nuclear spin maser. A method for efficient optical detection of spin has been developed and applied to the nuclear spin oscillator, and the frequency characteristics of the oscillator at low frequencies has been investigated. The spin oscillator was operated at frequencies 2.5-36 Hz. The frequency performance of the oscillator is discussed in relation to a planned search for an atomic electric dipole moment taking advantage of the present oscillator scheme. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physleta.2012.04.043

Is the 7/2(1)(-) Isomer State of S-43 Spherical? 査読

R. Chevrier, J. M. Daugas, L. Gaudefroy, Y. Ichikawa, H. Ueno, M. Hass, H. Haas, S. Cottenier, N. Aoi, K. Asahi, D. L. Balabanski, N. Fukuda, T. Furukawa, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, Y. Ishii, D. Kameda, T. Kubo, T. Nanao, G. Neyens, T. Ohnishi, M. M. Rajabali, K. Suzuki, H. Takeda, M. Tsuchiya, N. Vermeulen, H. Watanabe, A. Yoshimi

PHYSICAL REVIEW LETTERS 108 ( 16 ) 162501 2012年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYSICAL SOC

We report on the spectroscopic quadrupole moment measurement of the 7/2(1)(-) isomeric state in S-43(16)27 [E* = 320.5(5) keV, T-1/2 = 415(3) ns], using the time dependent perturbed angular distribution technique at the RIKEN RIBF facility. Our value, vertical bar Q(s) vertical bar = 23(3) efm(2), is larger than that expected for a single-particle state. Shell model calculations using the modern SDPF-U interaction for this mass region reproduce remarkably well the measured vertical bar Q(s) vertical bar, and show that non-negligible correlations drive the isomeric state away from a purely spherical shape.

DOI： 10.1103/PhysRevLett.108.162501

Isobaric analog resonances of the N=21 nucleus 35Si 査読

N. Imai, Y. Hirayama, Y. X. Watanabe, T. Teranishi, T. Hashimoto, S. Hayakawa, Y. Ichikawa, H. Ishiyama, S. C. Jeong, D. Kahl, S. Kubono, H. Miyatake, H. Ueno, H. Yamaguchi, K. Yoneda, A. Yoshimi

Physical Review C 85 ( 3 ) 2012年3月

Fe-57 charge states in MC-Si solar cells under light illumination after GeV-implantation of Mn-57 査読

Yutaka Yoshida, Kunifumi Suzuki, Yoshio Kobayashi, Takashi Nagatomo, Yuki Akiyama, Kenichi Yukihira, Kazuo Hayakawa, Hideki Ueno, Akihiro Yoshimi, Daisuke Nagae, Koichiro Asahi, Guido Langouche

HYPERFINE INTERACTIONS 204 ( 1-3 ) 133 - 137 2012年3月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：SPRINGER

Immediately after the GeV-implantation of Mn-57 nuclei produced by the RIKEN-RIBF facility, Mn-57/Fe-57 Mossbauer spectra in Si-solar cells are measured under light illumination. Comparing with the spectrum of p-type multi-crystalline-Si, the broad spectra of the solar cell under operation can be analyzed as a superposition of interstitial and substitutional Fe components with different charge states. The charge states of Fe impurities are created by the excess carrier injection followed by a directional carrier flow in the p-n junction. The present results provide us a possibility to clarify the carrier trapping process at the Fe impurities in Si-solar cells.

DOI： 10.1007/s10751-011-0424-3

Neutrino spectroscopy with atoms and molecules 招待査読

Atsushi Fukumi, Susumu Kuma, Yuki Miyamoto, Kyo Nakajima, Itsuo Nakano, Hajime Nanjo, Chiaki Ohae, Noboru Sasao, Minoru Tanaka, Takashi Taniguchi, Satoshi Uetake, Tomonari Wakabayashi, Takuya Yamaguchi, Akihiro Yoshimi, Motohiko Yoshimura

PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS 2012 ( 1 ) 04D002 2012年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：OXFORD UNIV PRESS INC

We systematically investigate the new experimental method of using atoms or molecules to measure the important parameters of neutrinos that are still to be determined: the absolute mass scale, the mass hierarchy pattern (normal or inverted), the neutrino mass type (Majorana or Dirac), and the CP-violating phases, including Majorana phases. Most of these observables are difficult to measure in neutrino oscillation experiments. There are advantages to using atomic targets, such as the closeness of available atomic energies to anticipated neutrino masses, over nuclear target experiments such as the end point spectrum of beta decay and two-electron line spectrum in the neutrinoless double beta decay, both of which address some of the overlapping objectives with atomic/molecular experiments. A disadvantage of using atomic targets, the smallness of rates, is overcome by the macro-coherent amplification mechanism. The atomic or molecular process we use is a cooperative deexcitation of a collective body of atoms in a metastable level vertical bar e > emitting a neutrino pair and a photon: vertical bar e > -> vertical bar g > + gamma + nu(i)nu(j), where nu(i)s are neutrino mass eigenstates. The macro-coherence is developed by trigger-laser irradiation of two colors, which frequently causes the two-photon process vertical bar e > <-> vertical bar g > + gamma + gamma, vertical bar e > + gamma <-> vertical bar g > + gamma inside the target. We discuss important aspects of the macro-coherence development in detail, by setting up the master equation for the target Bloch vector (whose components are population difference and medium polarization) and the propagating electric field. Our master equation includes the effects of phase decoherence of medium polarization and decay of population difference. The spectral rate (the number of events per unit time) of macro-coherent radiative emission of a neutrino pair has three parts, and is given by a factorized formula of the form (overall omega-independent rate denoted by Gamma(0)) x (spectral shape function denoted by I (omega)) x (time-evolving dynamical factor), where omega is the photon energy. The constant factor Gamma(0) determines the overall rate in the unit of 1/time, and for Xe it is of the order of 1Hz(n/10(22) cm(-3))(3) (V/10(2) cm(3)). The dynamical factor is time dependent and is given by the space integrated quantity, over the entire target, of the product of the magnitude squared of the coherent polarization and the field strength (in the units of the maximally extractable energy density) stored inside the target. The asymptotic value of the time-evolving dynamical factor is given by the contribution of the field condensate accompanied by macroscopic coherence, which is calculated using the static limit of the master equation. With an appropriate choice of heavy target atoms or molecules such as Xe and I-2 that have a large M1 x E1 matrix element between vertical bar e > and vertical bar g >, we show that one can determine three neutrino masses along with distinction of the mass hierarchy pattern (normal or inverted) by measuring the spectral shape I (omega).If one uses a target of available energy of a fraction of 1 eV, the most experimentally challenging observable, the Majorana CP phases may be determined, comparing the detected rate with differences of theoretical expectations which exist at the level of several percent. The Majorana CP-violating phase is expected to be crucial to the understanding of the matter-antimatter imbalance in our universe. Our master equation, when applied to E1 x E1 transitions such as pH(2) vibrational Xv = 1 -> 0, can describe explosive paired superradiance events in which most of the energy stored in vertical bar e > is released in the order of a few nanoseconds. The present paper is intended to be self-contained, explaining some details of related theoretical works in the past, and reports on new simulations and the ongoing experimental efforts of the project to realize neutrino mass spectroscopy using atoms/molecules.

DOI： 10.1093/ptep/pts066

Production of spin-aligned RI beam via two-step fragmentation with dispersion matching 査読

Y. Ichikawa, H. Ueno, Y. Ishii, T. Furukawa, A. Yoshimi, D. Kameda, H. Watanabe, N. Aoi, K. Asahi, D. L. Balabanski, R. Chevrier, J. M. Daugas, N. Fukuda, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, T. Kubo, T. Nanao, T. Ohnishi, K. Suzuki, M. Tsuchiya, H. Takeda, M. M. Rajabali

RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011 381 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

To produce a radioactive-isotope (RI) beam with high spin alignment, we have developed a novel method, the two-step projectile-fragmentation (PF) method, that employs momentum-dispersion matching. An on-line experiment to produce Al-32 from Ca-48 via Al-33 was performed at RIKEN RI Beam Factory. In the experiment, we succeeded in producing approximately 8% spin alignment in an RI beam of Al-32. In this paper, we focus on evaluating the magnitude of spin alignment realized in one-nucleon removal from Al-33.

DOI： 10.1088/1742-6596/381/1/012090

QUADRUPOLE MOMENT OF THE 7/2(1) ISOMER STATE OF S-43M 査読

R. Chevrier, J. M. Daugas, L. Gaudefroy, Y. Ichikawa, H. Ueno, M. Hass, H. Haas, S. Cottenier, N. Aoi, K. Asahi, D. L. Balabanski, N. Fukuda, T. Furukawa, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, Y. Ishii, D. Kameda, T. Kubo, T. Nanao, G. Neyens, T. Ohnishi, M. M. Rajabali, K. Suzuki, H. Takeda, M. Tsuchiya, N. Vermeulen, H. Watanabe, A. Yoshimi

PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON EXOTIC NUCLEI (EXON 2012) 59 - 66 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

We report on the spectroscopic quadrupole moment of the 7/2 isomer state [E*=320.5(5) keV, T-1/2=415(5) ns, vertical bar Q(s)vertical bar=23(3) efm(2)] in the neutron-rich S-43 nucleus, using the Time Dependent Perturbed Angular Distribution (TDPAD) method at RIKEN. The measured vertical bar Qs vertical bar is larger than that expected for a single particle state. Comparison to shell model calculations performed using the SDPF-U interaction, show that correlations drive the isomeric state away from a purely spherical shape.

Development of longitudinal-gradient magnet for time focusing of ultra-cold neutron with anisotropic inter-pole 査読

Yasushi Arimoto, Yoshihisa Iwashita, Tamaki Yoshioka, Masaaki Kitaguchi, Sohei Imajo, Hirohiko M. Shimizu, Koichiro Asahi, Takashi Ino, Yoshio Kamiya, Kenji Mishima, Suguru Muto, Kenji Sakai, Tatsushi Shima, Kaoru Taketani, Satoru Yamashita, Akihiro Yoshimi

IEEE Transactions on Applied Superconductivity 22 ( 3 ) 2012年

掲載種別：研究論文（学術雑誌）

Ultra-cold neutron (UCN) is attractive for a search of the neutron electric dipole moment (nEDM). It is crucial to store UCNs with high density in a bottle for nEDM measurement apparatus. To increase the density, time focusing technique can be useful, where slow neutrons are accelerated and fast neutrons are decelerated by using magnetic potential. This device is called rebuncher. The rebuncher consists of a gradient magnet, RF coil, and neutron guide. The magnet generates a field gradient of 3.5 T/m (from 1 T to 0.2 T within 24 cm) in the longitudinal direction. By using anisotropic inter-poles, the magnet is compact and keeps the gradient uniform. The fabricated magnet showed good performance as designed. © 2012 IEEE.

DOI： 10.1109/TASC.2012.2183569

Frequency characteristics of a nuclear spin maser for the search for the electric dipole moment of Xe-129 atom 査読

T. Inoue, M. Tsuchiya, T. Furukawa, H. Hayashi, T. Nanao, A. Yoshimi, M. Uchida, Y. Matsuo, K. Asahi

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES 43 ( 3 ) 847 - 850 2011年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Frequency characteristics of a Xe-129 nuclear spin maser was studied, which is under development at Tokyo Institute of Technology for the search for a permanent electric dipole moment in diamagnetic Xe-129 atom. Drifts in the solenoid current and cell temperature were found to be the most influential factors on the maser frequency. From correlation coefficient analysis, there seem to exist other origins of frequency fluctuation, such as phase drifts in the maser oscillation. In order to improve the stability of the maser frequency, the intensity of the pumping laser required to fully polarize Xe-129 nuclei was evaluated. Construction of a polarization assessment system for Xe-129 gas cells and development of a new scheme of current stabilization are also remarked. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physe.2010.07.066

Development of high-sensitivity NMOR magnetometry for an EDM experiment 査読

T. Nanao, A. Yoshimi, T. Inoue, T. Furukawa, M. Tsuchiya, H. Hayashi, M. Uchida, K. Asahi

INTERNATIONAL NUCLEAR PHYSICS CONFERENCE 2010 (INPC): STANDARD MODEL TESTS AND FUNDAMENTAL SYMMETRIES 312 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

Developments are in progress aiming at the search for a permanent Electric Dipole Moment (EDM) in (129)Xe atom using a low-frequency nuclear spin maser. In the EDM experiment, drifts in the applied static magnetic field in a long time scale are the dominating source of errors in frequency determination The stability of the applied field and its monitoring by use of a high sensitivity magnetometer are thus the indispensable part of the EDM experiment. We are developing a magnetometer based on the Nonlinear Magneto-Optical Rotation (NMOR) effect in Rb atom. The sharp response to the magnetic field in this apparatus relies on a long relaxation time of the atomic spin alignment induced by linearly polarized laser light, and thus the suppression of the atomic decoherence should be essential for its sensitivity. Coating the inner walls of the cell with an antirelaxation layer, introducing a buffer gas in the cell and cancelling the transverse magnetic field should be effective in preventing atoms from depolarization. We obtained several NMOR spectra for Rb in cylindrical cells in such attempts. Up to now a sensitivity of delta B=1.5 x 10(-5) G has been attained in the present setup.

DOI： 10.1088/1742-6596/312/10/102015

Magnetic Field Stabilization for (129)Xe EDM Search Experiment 査読

Takeshi Furukawa, Takeshi Inoue, Tsubasa Nanao, Akihiro Yoshimi, Masato Tsuchiya, Hironori Hayashi, Makoto Uchida, Koichiro Asahi

INTERNATIONAL NUCLEAR PHYSICS CONFERENCE 2010 (INPC): STANDARD MODEL TESTS AND FUNDAMENTAL SYMMETRIES 312 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic (129)Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

DOI： 10.1088/1742-6596/312/10/102005

Search for an EDM in diamagnetic atom (129)Xe with nuclear spin maser technique 査読

Takeshi Inoue, Masato Tsuchiya, Hironori Hayashi, Tsubasa Nanao, Kunifumi Suzuki, Akihiro Yoshimi, Takeshi Furukawa, Makoto Uchida, Koichiro Asahi

INTERNATIONAL NUCLEAR PHYSICS CONFERENCE 2010 (INPC): STANDARD MODEL TESTS AND FUNDAMENTAL SYMMETRIES 312 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

Present status of the development of a nuclear spin maser for a (129)Xe atomic EDM search is reported. We studied the frequency behavior of the spin maser presently under operation, and found that the drift in the frequency is correlated with the maser amplitude drift. Also, a high-voltage application system for the (129)Xe precession cell was constructed. The leakage current measured is at present on the level of nA when a high voltage of 10 kV was applied, and is a subject of improvement to be achieved in near future.

DOI： 10.1088/1742-6596/312/10/102008

Search for an Electric Dipole Moment in Xe-129 Atom with Nuclear Spin Oscillator Technique 査読

K. Asahi, T. Furukawa, T. Inoue, A. Yoshimi, T. Nanao, M. Chikamori, K. Suzuki, M. Tsuchiya, H. Hayashi, M. Uchida, H. Ueno, Y. Matsuo, T. Fukuyama

INTERNATIONAL SYMPOSIUM: NANOSCIENCE AND QUANTUM PHYSICS 2011 (NANOPHYS'11) 302 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

Development of a nuclear spin oscillator intended for the experimental search for an electric dipole moment in Xe-129 atom is reported. The spin oscillation is brought about by polarizing Xe-129 nuclear spins by spin exchange with optically polarized Rb atoms, detecting the spin precession through the transmission of a circularly polarized laser light, and applying a feedback field according to the detected spins. Until present, a frequency precision, in a measurement time of T = 45,000 s, of delta nu = 5.2 nHz has been achieved.

DOI： 10.1088/1742-6596/302/1/012039

Experimental search for Xe-129 atomic EDM with nuclear spin maser technique 査読

T. Inoue, T. Furukawa, T. Nanao, A. Yoshimi, K. Suzuki, M. Chikamori, M. Tsuchiya, H. Hayashi, M. Uchida, K. Asahi

2ND INTERNATIONAL WORKSHOP ON THE PHYSICS OF FUNDAMENTAL SYMMETRIES AND INTERACTIONS (PSI) 17 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：ELSEVIER SCIENCE BV

The development of a nuclear spin oscillator system, namely a spin maser with an external feedback, for use in the search for Xe-129 atomic EDM is presented. By introducing a new current source for the B-0 field solenoid, drifts in the maser frequency were remarkably suppressed. This in turn clearly brought out the correlation between the maser frequency and the environmental field. Correcting for the effect of the environmental field, the frequency precision of 5 nHz in the measurement time of 45,000 s was attained. Origins of the remaining drifts in the maser frequency are now under investigation.

DOI： 10.1016/j.phpro.2011.06.024

Development of NMOR magnetometer for spin-maser EDM experiment 査読

A. Yoshimi, T. Nanao, T. Inoue, T. Furukawa, M. Uchida, M. Tsuchiya, H. Hayashi, M. Chikamori, K. Asahi

2ND INTERNATIONAL WORKSHOP ON THE PHYSICS OF FUNDAMENTAL SYMMETRIES AND INTERACTIONS (PSI) 17 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：ELSEVIER SCIENCE BV

We have been developing a high sensitivity atomic magnetometer for atomic EDM experiments using a low-frequency nuclear spin maser. In the developed nuclear spin maser of Xe-129, suppression of drift and fluctuation in the magnetic field is one of the important issues. The magnetometer being developed for spin maser EDM experiments utilizes the nonlinear magneto optical rotation (NMOR) effect in Rb atomic vapor. The enhancement of the optical rotation in a small magnetic field relies on the long spin-coherence time of Rb atoms in a vapor cell. The NMOR spectrum was measured by using fabricated Rb cells coated with an anti-relaxation material. The NMOR spectrum dependence on laser frequency, cell coating, and laser beam diameter were investigated. The magnetic sensitivity at present is 0.2 mu G/root Hz from observed NMOR and noise spectra.

DOI： 10.1016/j.phpro.2011.06.043

Longitudinal-gradient magnet for time focusing of ultra-cold neutrons

Y. Arimoto, T. Yoshioka, H. M. Shimizu, K. Mishima, T. Ino, K. Taketani, S. Muto, M. Kitaguchi, S. Imajo, Y. Iwashita, S. Yamashita, Y. Kamiya, A. Yoshimi, K. Asahi, T. Shima, K. Sakai

Physics Procedia 17 20 - 29 2011年

掲載種別：研究論文（国際会議プロシーディングス）

A gradient DC magnet is designed using 3D magnetic field analysis code. This magnet, referred to as a B magnet, is one of the key elements of a time-focusing device for ultra-cold neutrons (UCNs) based on a radio frequency gradient flipper - a so-called rebuncher. The magnet generates a guide and a potential field that interacts with the magnetic moment of UCNs and its main body comprises a C-shaped yoke made from iron. A field gradient is generated by a pole arrangement that includes an anisotropic inter-pole, which causes the fringe field to be uniform in the longitudinal direction even when the pole gap distance changes. The designed magnet has the following properties: (1) a maximum B-field of 10 kGauss, decreasing to 2 kGauss at a longitudinal distance of 25 cm, with a gradient of less than 400 Gauss/cm, (2) variations in the fringe field along the y direction is less than 4% over a range of -3 cm≤ y ≤ 3 cm at any z position in the spin-flipping region. Tracking simulations show that the B magnet is capable of accepting UCNs in the velocity range 2.3∼3.3 m/s. © 2011 Published by Elsevier B.V. 0 0

DOI： 10.1016/j.phpro.2011.06.013

18pSK-14 超流動ヘリウム中に打ち込まれた^<87>Rbビームのレーザー誘起蛍光観測と光ポンピング(18pSK 不安定核(II),実験核物理領域)

古川武, 松浦佑一, 加藤裕樹, 山口康広, 今村慧, 幕田将宏, 畠山温, 和田道治, 園田哲, 伊藤由太, 七尾翼, 涌井崇志, 小林徹, 西村俊二, 西村美月, 近藤洋介, 青井考, 米田健一郎, 久保野茂, 上野秀樹, 下田正, 篠塚勉, 佐々木彩子, 旭耕一郎, 松尾由賀利, 泉さやか, 市川雄一, 吉見彰洋, 田尻邦彦, 石井裕司, 吉田直貴

日本物理学会講演概要集 66 91 - 91 2011年

Photon detection from stopped ⁸⁷Rb atoms injected into superfluid helium for a new nuclear laser spectroscopy of rare radioisotopes

T. Furukawa, T. Wakui, A. Sasaki, S. Izumi, Y. Ichikawa, A. Yoshimi, K. Tajiri, Y. Ishii, N. Yoshida, Y. Matsuura, Y. Kato, Y. Yamaguchi, K. Imamura, M. Makuta, A. Hatakeyama, M. Wada, T. Sonoda, Y. Ito, T. Nanao, T. Kobayashi, S. Nishimura, M. Nishimura, Y. Kondo, N. Aoi, K. Yoneda, S. Kubono, Y. Ohshiro, H. Ueno, T. Shimoda, T. Shinozuka, K. Asahi, Y. Matsuo

Journal of Physics: Conference Series 302 ( 1 ) 2011年

掲載種別：研究論文（国際会議プロシーディングス）

We have been developing a new nuclear laser spectroscopic method "OROCHI" for determining spins and moments of exotic RIs. This is a method based on the combination of superfluid helium as a stopper of radioactive isotope (RI) beam and in-situ laser spectroscopy of RI atoms. This unique method will enable us to measure nuclear spins and electromagnetic moments of extremely low yield RI (less than 1 particle per second). To confirm the feasibility of this method for rare radioisotopes, we carried out the first on-line experiment with a 87Rb beam, aiming at evaluating the minimum beam intensity required for the measurement. The LIF (Laser Induced Fluorescence) photons from the 87Rb atoms stopped in He II are successfully observed in the on-line experiment. The obtained LIF intensity is nearly consistent with the intensity calculated from the photo-absorption cross section of atoms in He II.

DOI： 10.1088/1742-6596/302/1/012054

28pGK-2 ^<87>Rbビームを用いた超流動ヘリウム中でのレーザー核分光法開発実験(28pGK 検出器IV,実験核物理領域)

古川武, 松浦佑一, 加藤裕樹, 山口康広, 今村慧, 幕田将宏, 畠山温, 和田道治, 園田哲, 伊藤由太, 七尾翼, 涌井崇志, 小林徹, 西村俊二, 西村美月, 近藤洋介, 青井考, 米田健一郎, 久保野茂, 大城幸光, 上野秀樹, 下田正, 佐々木彩子, 篠塚勉, 旭耕一郎, 松尾由賀利, 泉さやか, 市川雄一, 吉見彰洋, 田尻邦彦, 石井裕司, 吉田直貴

日本物理学会講演概要集 66 99 - 99 2011年

Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon

Tetsuya Ohnishi, Toshiyuki Kubo, Kensuke Kusaka, Atsushi Yoshida, Koichi Yoshida, Masao Ohtake, Naoki Fukuda, Hiroyuki Takeda, Daisuke Kameda, Kanenobu Tanaka, Naohito Inabe, Yoshiyuki Yanagisawa, Yasuyuki Gono, Hiroshi Watanabe, Hideaki Otsu, Hidetada Baba, Takashi Ichihara, Yoshitaka Yamaguchi, Maya Takechi, Shunji Nishimura, Hideki Ueno, Akihiro Yoshimi, Hiroyoshi Sakurai, Tohru Motobayashi, Taro Nakao, Yutaka Mizoi, Masafumi Matsushita, Kazuo Ieki, Nobuyuki Kobayashi, Kana Tanaka, Yosuke Kawada, Naoki Tanaka, Shigeki Deguchi, Yoshiteru Satou, Yosuke Kondo, Takashi Nakamura, Kenta Yoshinaga, Chihiro Ishii, Hideakira Yoshii, Yuki Miyashita, Nobuya Uematsu, Yasutsugu Shiraki, Toshiyuki Sumikama, Junsei Chiba, Eiji Ideguchi, Akito Saito, Takayuki Yamaguchi, Isao Hachiuma, Takeshi Suzuki, Tetsuaki Moriguchi, Akira Ozawa, Takashi Ohtsubo, Michael A. Famiano, Hans Geissel, Anthony S. Nettleton, Oleg B. Tarasov, Daniel P. Bazin, Bradley M. Sherrill, Shashikant L. Manikonda, Jerry A. Nolen

Journal of the Physical Society of Japan 79 ( 7 ) 073201 - 073201 2010年7月

Precise nuclear moments of extremely proton-rich nuclus Al-23

T. Nagatomo, H. Ueno, M. Mihara, K. Matsuta, A. Yoshimi, Y. Ichikawa, K. Yamada, H. Kawamura, A. Ozawa, T. Moriguchi, Y. Ishibashi, K. Asahi, M. Uchida, K. Suzuki, T. Inoue, Y. Hasama, H. Iijima, T. Sumikama, M. Fukuda, T. Minamisono

HYPERFINE INTERACTIONS 198 ( 1-3 ) 103 - 107 2010年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：SPRINGER

Electric quadrupole coupling constant eqQ/h of the extremely proton-rich Al-23 (wI(pi) = 5/2(+), T-1/2 = 0.47 s) nucleus implanted into an Al2O3 single crystal has been measured for the first time, using the beta-ray detecting nuclear quadrupole resonance method (beta-NQR) in a high magnetic field. As a preliminary result, the quadrupole coupling constant was determined as vertical bar eqQ/h(Al-23)vertical bar = 2.66 +/- 0.77 MHz. Using the quadrupole coupling constant of Al-27 in Al2O3 as a reference, the Q moment of the ground state of Al-23 was extracted as vertical bar Q(Al-23)vertical bar similar to 160 mb, which is well explained by the shell model calculation in the sd-shell model space with the USD interaction.

DOI： 10.1007/s10751-010-0262-8

Beta-NMR measurement of ⁵⁸Cu in Si

M. Mihara, T. Izumikawa, H. Ueno, K. Matsuta, D. Nishimura, T. Nagatomo, T. Moriguchi, Y. Ito, D. Nagae, M. Fukuda, A. Yoshimi, K. Yamada, M. Takechi, Y. Ichikawa, S. Momota, Y. Hirayama, T. Ohtsubo, S. Suzuki, T. Kubo, Y. Namiki, A. Ozawa, Y. Ishibashi, H. Oishi, K. Suzuki, I. Hachiuma, K. Namihira, D. Horikawa, T. Minamisono, T. Yamaguchi, T. Kuboki, T. Suzuki, K. Satoh, Y. Kobayashi, K. Asahi, K. Matsukawa, K. Shirai

Hyperfine Interactions 197 ( 1 ) 143 - 147 2010年

掲載種別：研究論文（学術雑誌）

The β-NMR study of short-lived nucleus 58Cu (Iπ = 1+, T1/2 = 3.2 s) in Si has been performed. Spin polarization of 58Cu induced by the charge exchange reaction of 58Ni was observed in Si at 15 K. The 58Cu magnetic moment {pipe}μ[58Cu]{pipe} = (0.46±0.03)μN deduced from the β-NMR spectrum is consistent with the previous results on the laser spectroscopy. The present result shows that the 58Cu nucleus is promising as a new nuclear probe for the microscopic study of Cu impurities in Si. © 2010 Springer Science+Business Media B.V.

DOI： 10.1007/s10751-010-0249-5

Electric quadrupole moment of the neutron-rich Al-33 査読

T. Nagatomo, K. Shimada, K. Asahi, D. L. Balabanski, J. M. Daugas, M. Depuydt, M. De Rydt, L. Gaudefroy, S. Grevy, Y. Hasama, Y. Ichikawa, D. Kameda, P. Morel, L. Perrot, C. Stoedel, J. C. Thomas, W. Vanderheijden, N. Vermeulen, P. Vingerhoets, A. Yoshimi, G. Neyens, H. Ueno

EUROPEAN PHYSICAL JOURNAL A 42 ( 3 ) 383 - 385 2009年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

The nuclear electric quadrupole moment (Q moment) of the neutron-rich nucleus Al-33 (I = 5/2, T-1/2 = 41 ms) has been measured by the beta-ray detected nuclear quadrupole resonance (beta-NQR) method for the first time. The Al-33 nucleus is considered to be on the border of the island of inversion within which a significant intrusion of the pf orbits occurs across the N = 20 shell gap and the intrusion causes an anomalous enhancement of the Q moment. Polarized Al-33 nuclei were produced from S-36 (77.5MeV/u) beams through the fragmentation process and separated by LISE fragment separator at GANIL. The Al-33 nuclei were implanted into a Al2O3 single-crystal plate and the beta-NQR spectrum was successfully obtained.

DOI： 10.1140/epja/i2009-10885-3

g factors of N17and N18 remeasured

M. De Rydt, D. L. Balabanski, J. M. Daugas, P. Himpe, D. Kameda, R. Lozeva, P. Morel, L. Perrot, K. Shimada, C. Stödel, T. Sugimoto, J. C. Thomas, H. Ueno, N. Vermeulen, P. Vingerhoets, A. Yoshimi, G. Neyens

Physical Review C 80 ( 3 ) 2009年9月

Ground-state electric quadrupole moment of Al31

D. Nagae, H. Ueno, D. Kameda, M. Takemura, K. Asahi, K. Takase, A. Yoshimi, T. Sugimoto, K. Shimada, T. Nagatomo, M. Uchida, T. Arai, T. Inoue, S. Kagami, N. Hatakeyama, H. Kawamura, K. Narita, J. Murata

Physical Review C 79 ( 2 ) 2009年2月

Nuclear Spin Maser at Highly Stabilized Low Magnetic Field and Search for Atomic EDM 査読

A. Yoshimi, K. Asahi, T. Inoue, M. Uchida, N. Hatakeyama, M. Tsuchiya, S. Kagami

SPIN PHYSICS 1149 249 - + 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

Nuclear Structure Studies with Polarized Radioactive Beams 査読

K. Asahi, H. Ueno, K. Shimada, T. Nagatomo, A. Yoshimi, D. Nagae, D. Kameda, M. Uchida, T. Inoue, M. Hatakeyama, S. Kagami, Y. Hasama, K. Suzuki, J. Murata, H. Kawamura, K. Narita, M. Ishihara

SPIN PHYSICS 1149 90 - + 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Nuclear moment studies on nuclei far from the P-stability line, performed by taking advantage of the projectile fragmentation reaction, are reviewed. A method to produce spin polarization/alignment in the projectile fragments was developed and utilized for the beta-NMR/NQR measurements. Several new findings in nuclear structure physics were obtained from the nuclear moment experiments done with these techniques.

Precision measurement of the electric quadrupole moment of 31Al and determination of the effective proton charge in the sd-shell 査読

M. De Rydt, G. Neyens, K. Asahi, D.L. Balabanski, J.M. Daugas, M. Depuydt, L. Gaudefroy, S. Grevy, Y. Hasama, Y. Ichikawa, P. Morel, T. Nagatomo, T. Otsuka, L. Perrot, K. Shimada, C. Stodel, J.C. Thomas, H. Ueno, Y. Utsuno, W. Vanderheijden, N. Vermeulen, P. Vingerhoets, A. Yoshimi

Phys. Lett. B 678 ( 4 ) 344 - 349 2009年

29pZC-10 超流動ヘリウム中での光ポンピング法を用いたAg原子の高偏極生成とレーザー核分光への応用(29pZC 実験核物理領域,理論核物理領域合同不安定核(合同)II,実験核物理領域)

古川武, 山口杏子, 和田道治, 園田哲, 高峰愛子, 上野秀樹, 吉見彰洋, 青井考, 西村俊二, 栂野泰宏, 武智麻耶, 藤掛浩太郎, 小田原厚子, 下田正, 篠塚勉, 本林透, 松尾由賀利, 畠山温, 小林徹, 松浦佑一, 佐々木彩子, 星野紗代, 涌井崇志, 風戸正行

日本物理学会講演概要集 64 80 - 80 2009年

29pZC-8 超流動ヘリウム中でのレーザー核分光に向けた蛍光検出系の開発(29pZC 実験核物理領域,理論核物理領域合同不安定核(合同)II,実験核物理領域)

佐々木彩子, 小林徹, 上野秀樹, 吉見彰洋, 青井考, 西村俊二, 栂野泰宏, 武智麻耶, 畠山温, 藤掛浩太郎, 松浦佑一, 星野紗代, 小田原厚子, 下田正, 本林透, 篠塚勉, 松尾由賀利, 涌井崇志, 古川武, 風戸正行, 山口杏子, 和田道治, 園田哲, 高峰愛子

日本物理学会講演概要集 64 80 - 80 2009年

Electric quadrupole moment of 31Al

D. Nagae, H. Ueno, D. Kameda, M. Takemura, K. Asahi, K. Takase, A. Yoshimi, T. Sugimoto, K. Shimada, T. Nagatomo, M. Uchida, T. Arai, T. Inoue, S. Kagami, N. Hatakeyama, J. Murata, H. Kawamura, K. Narita

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 266 ( 19-20 ) 4612 - 4615 2008年10月

Temperature-Dependent Behavior of Impurity Atoms Implanted in Highly Oriented Pyrolytic Graphite –An Application of a New Online TDPAC Method– 査読

Journal of the Physical Society of Japan 77 ( 9 ) 2008年9月

Optical-coupling nuclear spin maser under highly stabilized low static field 査読

A. Yoshimi, T. Inoue, M. Uchida, N. Hatakeyama, K. Asahi

HYPERFINE INTERACTIONS 181 ( 1-3 ) 111 - 114 2008年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

A nuclear spin maser of a new type, that employs a feedback scheme based on optical nuclear spin detection, has been fabricated. The spin maser is operated at a low static field of 30 mG by using the optical detection method. The frequency stability and precision of the spin maser have been improved by a highly stabilized current source for the static magnetic field. An experimental setup to search for an electric dipole moment (EDM) in (129)Xe atom is being developed.

DOI： 10.1007/s10751-008-9630-z

Online time-differential perturbed angular correlation study with an O-19 beam - Residence sites of oxygen atoms in highly oriented pyrolytic graphite 査読

W. Sato, H. Ueno, H. Watanabe, H. Miyoshi, A. Yoshimi, D. Kameda, T. Ito, K. Shimada, J. Kalhara, S. Suda, Y. Kobayashi, A. Shinohara, Y. Ohkubo, K. Asahi

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 266 ( 2 ) 316 - 322 2008年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The online time-differential perturbed angular correlation (TDPAC) method was applied to a study of the physical states of a probe F-19, the beta(-) decay product of O-19 (t(1/2) = 26.9 s), implanted in highly oriented pyrolytic graphite. The observed magnitude of the electric field gradient at the probe nucleus, vertical bar V-zz vertical bar = 2.91(17) x 10(22) V m(-2), suggests that the incident O-19 atoms are stabilized at an interlayer position with point group C-3v. Exhibiting observed TDPAC spectra having a clear sample-to-detector configuration dependence, we demonstrate the applicability of the present online method with a short-lived radioactive O-19 beam. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nimb.2007.11.001

Development of atomic-beam resonance method to measure the nuclear moments of unstable nuclei

T. Sugimoto, K. Asahi, H. Kawamura, J. Murata, D. Nagae, K. Shimada, H. Ueno, A. Yoshimi

Hyperfine Interactions 181 ( 1-3 ) 141 - 144 2008年1月

22aSD-5 超流動ヘリウム中における短寿命核のレーザー核分光実験計画『OROCHI』の現状(22aSD 核構造・基礎物理・軽イオン,実験核物理領域)

古川武, 青井考, 武智麻耶, 小林徹, 和田道治, 園田哲, 高峰愛子, 栂野泰宏, 藤掛浩太郎, 松浦佑一, 小田原厚子, 松尾由賀利, 下田正, 篠塚勉, 本林透, 畠山温, 風戸正行, 星野紗代, 佐々木彩子, 涌井崇志, 上野秀樹, 吉見彰洋

日本物理学会講演概要集 63 65 - 65 2008年

Fe-57 diffusion in n-type Si after GeV implantation of Mn-57 査読

Y. Yoshida, Y. Kobayashi, K. Yukihira, K. Hayakawa, K. Suzuki, A. Yoshida, H. Ueno, A. Yoshimi, K. Shimada, D. Nagae, K. Asahi, G. Langouche

PHYSICA B-CONDENSED MATTER 401 101 - 104 2007年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

At the RI-beam facility of the RIKEN, Mn-57/Fe-57 isotopes are separated and implanted into n-type FZ-Si (6 x 10(16) As/cm(3)), and subsequently the atomic jump processes of Fe-57 in the Si matrix are observed by Mossbauer spectroscopy on a time scale of 100 ns between 330 and 1200 K. The spectra consist of two components due to "interstitial Fe" and "substitutional Fe", both of which yield the same isomer shifts as those reported in p-type Si, showing long-range diffusion with increasing temperature. The spectra are compared with those simulated from a theoretical model. (C) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2007.08.122

Electric quadrupole moments of neutron-rich nuclei Al-32 and Al-31 査読

D. Kameda, H. Ueno, K. Asahi, D. Nagae, M. Takemura, K. Shimada, A. Yoshimi, T. Nagatomo, T. Sugimoto, M. Uchida, T. Arai, K. Takase, S. Suda, T. Inoue, J. Murata, H. Kawamura, H. Watanabe, Y. Kobayashi, M. Ishihara

HYPERFINE INTERACTIONS 180 ( 1-3 ) 61 - 64 2007年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

The electric quadrupole moments for the ground states of Al-32 and Al-31 have been measured by the beta ray-detected nuclear quadrupole resonance method. Spin-polarized Al-32 and Al-31 nuclei were obtained from the fragmentation of Ar-40 projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal alpha-Al2O3 stopper. The measured Q moment of Al-32, vertical bar Q(Al-32)vertical bar = 24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of Al-31 is considerably smaller than the sd calculations.

DOI： 10.1007/s10751-008-9685-x

Nuclear moments of neutron-rich aluminum isotopes 査読

H. Ueno, D. Kameda, D. Nagae, M. Takemura, K. Asahi, K. Shimada, K. Takase, T. Sugimoto, T. Nagatomo, M. Uchida, T. Arai, T. Inoue, A. Yoshimi, T. Kawamura, K. Narita

EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS 150 185 - 186 2007年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：EDP SCIENCES S A

Ground-state magnetic-dipole moments (mu) of Al30-32 and electric quadrupole moments (Q) of Al-31,Al- 32 have been measured with the beta-NMR method using spin- polarized radioactive-isotope beams produced in projectile-fragmentation reactions. Beams of Al30-32 were obtained by using RIKEN projectile-fragment separator RIPS after the fragmentation of Ar-40 projectiles at an energy of E = 95AMeV on a Nb-93 target. The obtained mu(exp)[Al30-32] and Q(exp)[Al-32] values agree well with shell-model calculations within the sd shell using the USD interaction. Also, Q(exp)[Al-31] was found to be small. Thus, we can conclude that these aluminum isotopes are located outside the island of inversion.

DOI： 10.1140/epjst/e2007-00299-y

Production of spin-polarized (17)N beam using inverse-kinematics low-energy transfer reactions 査読

K. Shimada, D. Nagae, K. Asahi, T. Inoue, K. Takase, S. Kagami, N. Hatakeyama, Y. Kobayashi, H. Ueno, A. Yoshimi, D. Kameda, T. Nagatomo, T. Sugimoto, S. Kubono, H. Yamaguchi, Y. Wakabayashi, G. Amadio, S. Hayakawa, J. Murata, H. Kawamura

HYPERFINE INTERACTIONS 180 ( 1-3 ) 43 - 47 2007年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

A new method to produce spin-polarized radioactive nuclear beams has been developed, which takes advantage of the low-energy transfer reaction in inverse kinematics. The method provides beam energies of a convenient range so that they may be implanted in a thin stopper, yet allowing the stopper to be spatially separated from the production target. The presence of polarizations of sizes at least vertical bar P vertical bar similar to 0.5% has has been confirmed for a (17)N beam obtained from (9)Be((18)O, (17)N) reaction at theta(Lab) similar to -1.7 degrees.

DOI： 10.1007/s10751-008-9626-8

Measurement of the electric quadrupole moment of Al-32 査読

D. Kameda, H. Ueno, K. Asahi, M. Takemura, A. Yoshimi, T. Haseyama, M. Uchida, K. Shimada, D. Nagae, G. Kijima, T. Arai, K. Takase, S. Suda, T. Inoue, J. Murata, H. Kawamura, Y. Kobayashi, H. Watanabe, M. Ishihara

PHYSICS LETTERS B 647 ( 2-3 ) 93 - 97 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The electric quadrupole moment Q for the ground state of Al-32 has been measured using the beta-NMR technique. Spin-polarized Al-32 nuclei were obtained from the fragmentation of Ar-40 projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal alpha-Al2O3 stopper. The quadrupole moment was deduced from the measured quadrupole coupling constant. The obtained value, vertical bar Q((32)Alg.s.)vertical bar = 24(2) mb, is remarkably small as compared with other Al isotopes, but is well explained by shell model calculations within the sd shell. The present result indicates that Al-32 has a normal sd-shell structure, in contrast to the neighboring N = 19 isotone Mg-31 for which a strongly deformed intruder ground state has been reported to occur. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1036/j.physletb.2007.01.063

Measurement of electric quadrupole moments for Al-31 using spin polarized RI beams 査読

D. Nagae, K. Asahi, H. Ueno, D. Kameda, M. Takemura, K. Takase, A. Yoshimi, T. Sugimoto, T. Nagatomo, Y. Kobayashi, M. Uchida, K. Shimada, T. Arai, T. Inoue, S. Kagami, N. Hatakeyama

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 853 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

The electromagnetic moment is a sensitive probe to investigate microscopic structure. In order to measure the electromagnetic moment beta-NMR and beta-NQR methods are employed taking advantage of the fragment spin polarization produced by the fragmentation reaction. The measurement of the electric quadrupole moment for ground-state Al-31 has been been carried out by beta-NQR method. Spin-polarized Al-31 nuclei were obtained from the fragmentation of Ar-40 projectiles, and were implanted in alpha-Al2O3 stopper. The electric quadrupole moment was deduced from the measured quadrupole coupling constant. The obtained value is vertical bar Q(Al-31)vertical bar = 104(9) e center dot mb.

Search for an atomic EDM with optical-coupling nuclear spin oscillator 査読

K. Asahi, M. Uchida, A. Yoshimi, T. Inoue, N. Hatakeyama

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 206 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

We have constructed a nuclear spin oscillator of a new type, that employs a feedback scheme based on an optical spin detection and suceeding spin control by a transverse field application. This spin oscillator parallels the conventional spin maser in many points, but exhibits advantages and requirements that are different from those with the spin maser. By means of the optical-coupling nuclear spin oscillator, an experimental setup to search for an electric dipole moment (EDM) in a spin 1/2 diamagnetic atom Xe-129 is being developed.

Production of spin-polarized radioactive ion beams via projectile fragmentation reaction 査読

D. Kameda, H. Ueno, K. Asaw, D. Nagae, A. Yoshimi, T. Nagatomo, T. Sugimoto, M. Uchida, M. Takemura, K. Shimada, K. Takase, T. Inoue, G. Kijima, T. Arai, S. Suda, J. Murata, H. Kawamura, Y. Kobayashi, H. Watanabe, M. Ishihara

PSTP 2007 980 283 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Spin-polarized radioactive ion beams are produced in the projectile fragmentation reaction induced by intermediate-energy heavy ion beams. The degree of spin polarization shows characteristic dependence on the outgoing momentum of the projectile fragment in the magnitude around 1 similar to 10 %. The qualitative behavior is well described by the kinematical model of the fragmentation process. Recently, we have successfully produced spin-polarized beams of aluminum isotopes in the mass A similar to 30 region via the fragmentation of 95 MeV/u Ar-40 projectiles. The magnetic moments of Al-30 and Al-32 and the electric quadrupole moments of Al-31 and Al-32 have been measured using the beta-NMR technique with the polarized RI beams of the Al isotopes.

Nuclear moment measurements of neutron-rich aluminum isotopes using spin-polarized RI beams: Determination of the boundary of the "Island of inversion" 査読

D. Kameda, H. Ueno, K. Asah, M. Takemura, D. Nagae, K. Shimada, A. Yoshimi, Y. Kobayashi, T. Haseyama, M. Uchida, K. Takase, T. Arai, T. Inoue, S. Suda, J. Murata, H. Kawamura, H. Watanabe, M. Ishihara

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 845 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

The electric quadrupole moment Q for the ground state of Al-32 has been measured using the beta-NMR technique. Spin-polarized Al-32 nuclei were obtained from the fragmentation of 40 Ar projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal alpha-Al2O3 stopper. The quadrupole moment was deduced from the measured quadrupole coupling constant. The obtained value, vertical bar Q(Al-32(g.s.))vertical bar = 24(2) mb, was well reproduced by shell model calculations within the sd shell, indicating that Al-32 is a normal sd-shell nucleus. The result is in sharp contrast to the strongly deformed nuclei Mg-32 and Mg-31 neighboring the Al-32 isotope.

Beta neutrino correlation and T-Violation experiment in nuclear beta decay 査読

J. Murata, K. Asahi, D. Kameda, H. Kawamura, D. Nagae, K. Narita, K. Shimada, T. Shimoyama, T. Shuehiro, T. Toyoda, M. Uchida, H. Ueno, A. Yoshimi

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 ( 1 ) 218 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Precision measurement of nuclear beta decay correlations at newly constructing RIKEN-RIBF and KEK-TRIAC is planned. Measurements of beta neutrino correlation and T-violating electron transverse polarization using spin polarized RI beams are aimed to be performed using slow radioactive nuclei.

DOI： 10.1063/1.2750766

Developments of atomic beam resonance method with RI beams 査読

A. Yoshimi, H. Ueno, T. Sugimoto, K. Shimada, D. Nagae, J. Murata, H. Kawamura, D. Kameda, K. Asahi

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 ( 1 ) 849 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

The new scheme to produce a spin-polarized RI beam is being developed, in which the atomic beam resonance method is utilized for spin polarization. A gas-filled chamber to stop the incoming RI ions and to drift them into vacuum area has been developed. The measurement of RI-stopping in the gas was performed, and experiments for drifting and extracting of the stopped ions are now being performed. The status of the R&D for realizing the scheme is reported in this letter.

DOI： 10.1063/1.2750910

Measurement of nuclear moments at RIKEN 査読

H. Ueno, D. Kameda, D. Nagae, M. Takemura, K. Asahi, K. Takase, A. Yoshimi, T. Sugimoto, T. Nagatomo, T. Arai, M. Uchida, K. Shimada, T. Inoue, J. Murata, H. Kawamura, K. Narita

TOURS SYMPOSIUM ON NUCLEAR PHYSICS VI 891 ( 1 ) 113 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Based on the technique of fragment-induced spin polarization combined with the beta-NMR method, we have recently carried out experiments at RIKEN to measure nuclear moments of neutron-rich aluminum isotopes. In the measurements, the nuclear magnetic-dipole moments of Al-30,Al- 32 and the electric-quadrupole moments of Al-31,Al-32 have been determined. The obtained magnetic moments, as well as the other known magnetic moments of aluminum isotopes, agree well with shell model calculations with the USD interaction. The obtained quadrupole moments are smaller than those of Al-27,Al- 28, suggesting spherical shapes of Al-31,Al- 32. These results seem to suggest that Al-31 and Al-32 are located outside the island of inversion. In near future, studies on nuclear moments will be extended further in the RIKEN RIBF project, in which medium- and heavy-mass regions come within our scope by using superconducting fragment separator BigRIPS. Also, an upgrade program for the existing fragment separator RIPS is in progress. In the RIBF project, nuclear moments will be measured for isomer states as well as ground states.

DOI： 10.1063/1.2713507

Electric quadrupole moments of neutron rich Al isotope 査読

A. Yoshimi, H. Ueno, D. Kameda, K. Asahi, D. Nagae, M. Takemura, K. Shimada, K. Takase, T. Sugimoto, M. Uchida, T. Arai, T. Inoue, J. Murata, H. Kawamura

INTERNATIONAL SYMPOSIUM ON EXOTIC NUCLEI 912 ( 1 ) 105 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

The electric quadrupole moment Q for the ground state of neutron-rich Al-31,Al-32 has been measured using beta-NMR method applied to spin-polarized projectile fragments. The obtained quadrupole moments are smaller than those of Al-27,Al-28, which suggests spherical shapes of Al-31,Al-32.

DOI： 10.1063/1.2746585

Nuclear-moment measurements at RIKEN and perspectives in RIBF 査読

H. Ueno, D. Kameda, D. Nagae, M. Takemura, K. Asahi, K. Takase, A. Yoshimi, T. Sugimoto, T. Nagatomo, K. Shimada, M. Uchida, T. Arai, T. Inoue, J. Murata, H. Kawamura, K. Narita

PROCEEDINGS OF THE 17TH INTERNATIONAL SPIN PHYSICS SYMPOSIUM 915 ( 1 ) 841 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Based on the technique of fragment-induced spin polarization combined with the NMR method, a series of experiments has been carried out at RIKEN for the nuclear-moment measurement of light unstable nuclei. The measurement will be extended further in the RIKEN RIBF project, where radioactive-isotope beams in the medium- and heavy-mass regions will be produced at higher energies and with higher intensities compared with the RARF facility. Measurements of the isomeric-state nuclear moments of unstable nuclei will be started with BigRIPS by utilizing fragment-induced spin-orientation phenomena. Also, an upgrade program of the existing fragment separator RIPS is proposed in the phase-H program of RIBE Then, intense beams will be delivered to RIPS at E similar to 115 A MeV. This energy region is useful, not only because spin orientation is produced in the PF reaction but also they can be implanted into sample materials with limited thickness.

DOI： 10.1063/1.2750908

Structure of unstable nuclei from nuclear moments and β decays

K Asahi, M Uchida, K Shimada, D Nagae, D Kameda, H Ueno, A Yoshimi, M Takemura, T Arai, K Takase, T Inoue, H Kawamura, J Murata, H Watanabe, T Haseyama, Y Kobayashi, A Umeya, M Ishihara

Journal of Physics: Conference Series 49 79 - 84 2006年10月

Nuclear moments of neutron-rich 32Al

D. Kameda, H. Ueno, K. Asahi, M. Takemura, A. Yoshimi, T. Haseyama, M. Uchida, K. Shimada, D. Nagae, G. Kijima, T. Arai, K. Takase, S. Suda, T. Inoue, J. Murata, H. Kawamura, Y. Kobayashi, H. Watanabe, M. Ishihara

Journal of Physics: Conference Series 49 ( 1 ) 138 - 139 2006年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Physics Publishing

The magnetic moment and electric quadrupole moment of 32Al (Z 13,N 19) have been measured. We performed β-NMR spectroscopy with spin-polarized 32Al nuclei produced via the projectile fragmentation reaction. Both the moments are well reproduced by full sd-shell model calculations using the USD effective interaction. The result has provided clear evidence that 32Al is located out of the island of inversion. © 2006 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/49/1/030

Development of ion transportation, extraction and neutralization systems for atomic beam resonance method

Daisuke Nagae, Koichiro Asahi, Hisanori Miyoshi, Kenzi Shimada, Akihiro Yoshimi, Hideki Ueno, Jiro Murata, Makoto Uchida, Daisuke Kameda, Go Kato, Shoken Emori, Go Kijima, Sachiko Oshima, Makoto Takemura, Takemasa Arai, Yoshio Kobayashi, Tomohito Haseyama, W. D. Schmidt-Ott

Physica E: Low-Dimensional Systems and Nanostructures 29 ( 3-4 ) 580 - 583 2005年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

A device that produces a low-energy and largely spin polarized RI beam based on the atomic beam resonance method (RIABR) has been developed. We have performed measurements of stopping and drifting an incoming RI ion beam in a gas chamber, extraction of the ions into a vacuum region, and neutralization of the extracted low-energy ion beam. The drift efficiency of RI ions in a gas and the extraction efficiency at a Laval-type glass nozzle were found to be 0.72±0.04 and 0.033, respectively. The result of the experiment for the neutralization is also discussed. © 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physe.2005.06.031

Study of electromagnetic moments in unstable nuclei with radioactive nuclear beams

K Asahi, D Kameda, H Ueno, A Yoshimi, M Uchida, H Miyoshi, K Shimada, D Nagae, G Kijima, T Haseyama, H Watanabe, M Takemura, T Arai, S Oshima, A Umeya

Journal of Physics: Conference Series 20 59 - 64 2005年1月

Low-frequency nuclear spin maser and search for atomic EDM of Xe-129 査読

A Yoshimi, K Asahi, S Emori, M Uchida, S Oshima

Spin 2004: 16th International Spin Physics Symposium 247 - 250 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

We have developed a nuclear spin maser in which highly polarized nuclei of the noble gas isotope Xe-129 oscillate at the low frequency of 34 Hz. The system is advantageous for detecting a small frequency shift of the nuclear spin precession. We are thus planning to apply this system to the search for an atomic electric dipole moment of Xe-129. We here report the development of the system and its performance.

Magnetic moments of 30Al and 32Al

D. Kameda, K. Asahi, H. Miyoshi, K. Shimada, G. Kijima, D. Nagae, G. Kato, S. Emori, M. Tsukui, H. Ueno, A. Yoshimi, T. Haseyama, H. Watanabe, Y. Kobayashi, M. Ishihara

Czechoslovak Journal of Physics 55 ( 1 ) A327 - A332 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Kluwer Academic Publishers

The magnetic moments for 30Al and32Al have been measured by the β-NMR method with spin-polarized radioactive nuclear beams from the projectile-fragmentation reaction. The fragmentation processes that involved large numbers of removed nucleons, 10 and 8, from the projectiles 40Ar were successfully utilized to produce polarized 30Al and 32Al fragments. The obtained magnetic moments, μ30Al = (3.012± 0.021]μNand (μ32Al = (1.959 ± 0.019)μN, were reproduced well by shell model calculations within a model space of the full sd shell.

DOI： 10.1007/bf03032019

Application of the high-spin isomer beams to the secondary fusion reaction and the measurement of g-factor

H. Watanabe, K. Asahi, T. Kishida, H. Ueno, W. Sato, A. Yoshimi, Y. Kobayashi, D. Kameda, H. Miyoshi, T. Fukuchi, Y. Wakabayashi, T. Sasaki, M. Kibe, N. Hokoiwa, A. Odahara, B. Cederwall, K. Lagergren, Zs Podolyák, M. Ishihara, Y. Gono

Nuclear Physics A 746 ( 1-4 ) 540 - 543 2004年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier

A technique for providing high-spin isomers as probes of the fusion reaction and the measurement of g-factor has been worked out at RIKEN. In the study of the fusion reaction 12C(145mSm, xn)157-xEr, the γ rays emitted from the fusion-evaporation residue 154Er have been successfully observed. The nuclear g-factor of the T1/2 = 28 ns high-spin isomer in 149Dy has been measured with the γ-ray TDPAD method. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nuclphysa.2004.09.141

Lifetime of a new high-spin isomer in Dy-150 査読

H Watanabe, Y Wakabayashi, Y Gono, T Fukuchi, H Ueno, W Sato, A Yoshimi, D Kameda, H Miyoshi, T Kishida, Y Kobayashi, T Morikawa, S Motomura, O Kashiyama, K Saito, A Odahara, K Asahi

EUROPEAN PHYSICAL JOURNAL A 19 ( 2 ) 163 - 167 2004年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER-VERLAG

A new high-spin isomer in Dy-150 has been observed at an excitation energy of 10.3 MeV by combining the inverse-kinematic reaction induced by a pulsed beam of Xe-132 and the gamma-ray recoil-shadow technique. The half-life of this isomeric state has been determined to be T-1/2=1.6+/-0.6 ns using the conventional centroid-shift method with the Pr-141(O-16, p6n)Dy-150 reaction at 165 MeV. The mechanism producing high-spin isomers in N=83,84 isotones is qualitatively discussed in terms of the difference of the neutron particle-hole configuration between the high-spin isomer and the lower-lying state.

DOI： 10.1140/epja/i2003-10150-y

Lifetime of a new high-spin isomer in 150 Dy

H. Watanabe, Y. Wakabayashi, Y. Gono, T. Fukuchi, H. Ueno, W. Sato, A. Yoshimi, D. Kameda, H. Miyoshi, T. Kishida, Y. Kobayashi, T. Morikawa, S. Motomura, O. Kashiyama, K. Saito, A. Odahara, K. Asahi

The European Physical Journal A 19 ( 2 ) 163 - 167 2004年2月

Nuclear moments of nuclei in the neighborhood of the neutron drip line 査読

H Ueno, K Asahi, H Ogawa, D Kameda, H Miyoshi, A Yoshimi, H Watanabe, K Shimada, W Sato, K Yoneda, N Imai, Y Kobayashi, M Ishihara, WD Schmidt-Ott

LABYRINTH IN NUCLEAR STRUCTURE 701 135 - 142 2004年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Based on the beta-NMR method with spin-polarized radioactive-isotope beams, we have been conducting a series of experiments at RIKEN for the measurement the magnetic moments and electric quadrupole moments of light unstable nuclei. From the systematic measurements of nuclear moments in the unstable nuclear region, the effects of the neutron excess on the structure have been discussed. In the mu-moment measurements of the nitrogen isotopes, the outward-directed deviation of mu(N-17) and mu(N-19) from the Schmidt value were observed. In the case of Q-moment, our experimental data show large discrepancy from the shell-model predictions if neutron and proton effective charges are assumed to be constant. By introducing an isospin dependence to the effective charges, the observed Q-moments of boron isotopes can be explained. We also applied the result of mu-moment measurements to the I-pi assignment. Owing to the large difference of mu values among expected 1(pi) candidates, 1(pi)(C-17)=3/2(+) has been definitely assigned.

G-factor measurement for N-19 査読

D Kameda, K Asahi, H Miyoshi, K Shimada, G Kato, S Emori, G Kijima, H Ueno, A Yoshimi, H Watanabe, T Haseyama, Y Kobayashi, J Murata, W Sato, H Ogawa

NEW ERA OF NUCLEAR STRUCTURE PHYSICS 231 - 235 2004年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD

The magnetic moment of N-19 was measured by using a beta-NMR method and a spin-polarized N-19 beam from the fragmentation reaction. As a result, the g value for the N-19 ground state, g = 0.61 +/- 0.03(preliminary), was obtained. The value was compared with those of N-15 and N-17. Contrary to shell-mode predictions that the g value should increase with increasing number of neutrons in the sd shell, the obtained g for N-19(g.s.) is significantly smaller than the g factor for N-17(g.s.).

DOI： 10.1142/9789812702401_0035

g-factor of the high-spin isomer in Dy-149 and a multi-quasiparticle configuration caused by the N=82 core excitations 査読

H Watanabe, H Ueno, D Kameda, W Sato, A Yoshimi, H Miyoshi, T Kishida, Y Kobayashi, A Odahara, Y Gono, K Asahi

NUCLEAR PHYSICS A 728 ( 3-4 ) 365 - 378 2003年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The nuclear g-factor of the T-1/2 = 28 ns high-spin isomer in Dy-149 has been measured using the gamma-ray time-differential perturbed angular distribution (TDPAD) technique with a pulsed beam of Xe-132. The experimental value g = +0.41(6) is in good agreement with a fully aligned multi-quasiparticle configuration pi (h(11/2)(2)) circle times nu(f(7/2)h(9/2)i(13/2)(d(3/2)(-2))(0)) This result indicates that only neutron particle-hole excitations across the N = 82 shell-closure occur at this isomeric state. (C) 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nuclphysa.2003.09.007

Nuclear spin maser with an artificial feedback for fundamental physics 査読

A Yoshimi, K Asahi, K Yogo

CZECHOSLOVAK JOURNAL OF PHYSICS 53 B417 - B424 2003年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST PHYSICS ACAD SCI CZECH REPUBLIC

Low frequency spin precession of, the largely polarized Xe-129 nuclei was continuously maintained using the nuclear spin maser technique. This is aiming at the sensitive measurement of the energy shift of the nuclei which should be required in the search for the violation of the fundamental symmetries. It involves the optical detection system of the nuclear spin direction. and the artificial feedback system to maintain the spin precession beyond the intrinsic transverse relaxation time. Its operation was experimentally tested and the frequency properties were analyzed based on. the modified Bloch equations. The plans. of ail application,of the system to physical experiments are described.

On-line TDPAC studies with the O-19 beam 査読

W Sato, H Ueno, H Watanabe, H Ogawa, H Miyoshi, N Imai, A Yoshimi, K Yoneda, D Kameda, Y Kobayashi, K Asahi

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY 255 ( 1 ) 183 - 186 2003年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：KLUWER ACADEMIC PUBL

A new F-19 probe disintegrated from short-lived O-19 has been developed for the first time for time-differential perturbed angular correlation method. The angular correlation coefficient for the relevant cascade has been experimentally estimated to be A(22) = -0.17+/-0.01. As the first application of this technique to condensed matter physics, the probe was implanted in polycrystalline fullerene C-60. We have observed two contrastive perturbations acting on the probe nuclei, which reflect electrostatic and dynamic interactions with the extranuclear field.

DOI： 10.1023/A:1022216806445

DOI： 10.1023/a:1022216806445

Nuclear spin maser with an artificial feedback mechanism

A Yoshimi, K Asahi, K Sakai, M Tsuda, K Yogo, H Ogawa, T Suzuki, M Nagakura

Physics Letters A 304 ( 1-2 ) 13 - 20 2002年11月

Quenching of neutron E2 effective charge in neutron-rich nuclei and the ground-state spin-parity of C-17 査読

H Ogawa, K Asahi, H Ueno, H Sakai, H Miyoshi, D Kameda, T Suzuki, H Izumi, N Imai, YX Watanabe, K Yoneda, N Fukuda, H Watanabe, A Yoshimi, W Sato, N Aoi, M Nagakura, T Suga, K Yogo, A Goto, T Honda, Y Kobayashi, WD Schmidt-Ott, G Neyens, S Teughels, A Yoshida, T Kubo, N Ishihara

EUROPEAN PHYSICAL JOURNAL A 13 ( 1-2 ) 81 - 85 2002年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER-VERLAG

The electric quadrupole moment of B-17 and the g-factor of C-17 were measured by using the fragmentation-induced nuclear polarization technique combined with the beta-NMR method. The experimental quadrupole moment of B-17 is found strikingly close to that of the neutron closed-shell isotope B-13, indicating a strong quenching of the neutron E2 core-polarization charge. From the result obtained for the C-17 g-factor, we can conclude that the ground-state spin-parity of C-17 is 3/2(+).

Assignment of the Ground-State Spin-Parity for ^17C through g-Factor Measurement :

OGAWA Hiroshi, ASAHI Koichiro, UENO Hideki, MIYOSHI Hisanori, KAMEDA Daisuke, IMAI Nobuaki, YONEDA Ken-ichiro, WATANABE Hiroshi, SUGA Toshitaka, OHNO Ken-ichi, YOSHIMI Akihiro, SATO Wataru, SAKAI Kenji, YOGO Katsunori, KOBAYASHI Yoshio, YOSHIDA Atsushi, KUBO Toshiyuki, ISHIHARA Masayasu

Progress of theoretical physics. Supplement ( 146 ) 607 - 608 2002年

記述言語：英語出版者・発行元：Progress of Theoretical Physics

The g-factor for the ^17C ground state was measured by means of the β-NMR spectroscopy with a spin-polarized fragment beam. From the tentative result |g(^17C)| = 0.5054(25), we conclude that the ground-state spin-parity for ^17C is 3/2^+.

DOI： 10.1143/PTPS.146.607

その他リンク： https://projects.repo.nii.ac.jp/?action=repository_uri&item_id=240417

Assignment of the ground-state spin-parity for 17C through g-factor measurement

Hiroshi Ogawa, Koichiro Asahi, Hideki Ueno, Hisanori Miyoshi, Daisuke Kameda, Nobuaki Imai, Ken-Ichiro Yoneda, Hiroshi Watanabe, Toshitaka Suga, Ken-ichi Ohno, Akihiro Yoshimi, Wataru Sato, Kenji Sakai, Katsunori Yogo, Yoshio Kobayashi, Atsushi Yoshida, Toshiyuki Kubo, Masayasu Ishihara

Progress of Theoretical Physics ( 146 ) 607 - 608 2002年

Radioactive ion beams as microscopic probes into matter

Koichiro Asahi, Yoshio Kobayashi, Hideki Ueno, Akihiro Yoshimi, Wataru Sato, Hiroshi Watanabe, Hisanori Miyoshi, Daisuke Kameda

Anal. Sci. 17 Sup. i613 2001年

Effective charge anomaly in neutron-rich nuclei revealed from spin-polarized RI beam experiments 査読

H Ogawa, K Sakai, H Ueno, T Suzuki, H Miyoshi, M Nagakura, K Yogo, A Goto, T Suga, T Honda, N Imai, YX Watanabe, K Yoneda, A Yoshimi, N Fukuda, N Aoi, Y Kobayashi, WD Schmidt-Ott, G Neyens, S Teughels, A Yoshida, T Kubo, M Ishihara

SPIN 2000 570 679 - 683 2001年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

The electric quadrupole moment of B-17 was measured by means of spin polarized fragment beams produced by the projectile fragmentation reaction. The experimental quadrupole moment of 17B was very close to that of neutron p-shell closed nucleus B-13. This result indicates that the neutron effective charge for B-17 is considerably smaller than the value commonly used in the sd-shell region.

Nuclear moment studies with polarized radioactive nuclear beams 査読

K Asahi, H Ogawa, H Ueno, Y Kobayashi, W Sato, A Yoshimi, H Watanabe, D Kameda, H Miyoshi, K Sakai, N Imai, K Yoneda, YX Watanabe, N Fukuda, N Aoi, A Yoshida, T Kubo, M Ishihara

HYPERFINE INTERACTIONS 136 183 - 187 2001年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：KLUWER ACADEMIC PUBL

Magnetic dipole and electric quadrupole moments of nuclei in the light-mass neutron-rich region have been studied by taking advantage of spin-polarized radioactive nuclear beams that have been obtained from the projectile fragmentation reaction. Analyses of the results reveal a few interesting phenomena characteristic of nuclear structures in this region. In particular, we report in some detail the latest result on the magnetic moment of the 17 C ground state. The distinctly small value of the g-factor obtained, | g(C-17 | = 0.5054 +/- 0.0025, clearly excludes a I-pi = 1/2(+) candidate for the spin-parity assignment of this marginally bound nucleus, providing a reasonable account of the non-halo nature reported in recent breakup reaction experiments. Finally, future plans at the upcoming radioactive beam facility presently under construction at RIKEN are briefly mentioned.

Nuclear moment studies with polarized radioactive nuclear beams 査読

K Asahi, K Sakai, H Ogawa, H Ueno, Y Kobayashi, A Yoshimi, H Miyoshi, K Yogo, A Goto, T Suga, H Imai, YX Watanabe, K Yoneda, N Fukuda, N Aoi, WD Schmidt-Ott, G Neyens, S Teughels, A Yoshida, T Kubo, M Ishihara

SPIN 2000 570 109 - 118 2001年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

Beams of spin-polarized radioactive nuclei are produced in the projectile fragmentation reaction induced by intermediate-energy heavy ion beams, and are used for the measurement of magnetic dipole and electric quadrupole moments of nuclei in the regions far from stability. In this paper, after remarking the mechanism of fragment polarization and the experimental techniques to make use of it, we discuss the recent results obtained for the electromagnetic moments of light neutron-rich nuclei at RIKEN. Analyses of the observed magnetic moments in terms of shell models show intriguing results which imply that some of the basic nuclear properties, such as the order in energy of the single-particle orbits, the pairing energy between the excess neutrons, and the effective g(s)-factor for a halo nucleon, tend to alter as the degree of neutron excess increases. Also, the measured electric quadrupole moments reveal remarkable quenching of the E2 effective charge in nuclei with large N/Z ratios.

Novel spin maser mechanism studied for high-precision measurement of neutron electric dipole moment 査読

A Yoshimi, K Asahi, K Yogo, K Sakai, H Ogawa, T Suzuki, M Nagakura

SPIN 2000 570 353 - 357 2001年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AMER INST PHYSICS

We propose a new scheme of nuclear spin maser and have performed the experimental and theoretical analyses for its operation, aiming at the significant improvement, in sensitivity of neutron electric dipole moment (EDM). The proposed spin-masing scheme incorporates an artificial feedback mechanism, and is applicable to extremely low density systems of spins such as a bottled ensemble of UCNs. Its operation was experimentally demonstrated by using a spin-polarized Xe-129 gas as a model substance. The frequency analysis suggests that a frequency precision allowing a neutron EDM search with a sensitivity of 10(-28) ecm level is attainable by this maser scheme.

Development of a detector system for transient magnetic field experiments with radioactive-isotope beams and a test experiment 査読

H Ueno, W Sato, H Ogawa, N Aoi, K Yoneda, Y Kobayashi, D Kameda, H Miyoshi, H Watanabe, N Imai, A Yoshimi, J Kaihara, K Asahi

HYPERFINE INTERACTIONS 136 211 - 214 2001年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：KLUWER ACADEMIC PUBL

For g-factor measurements of excited states of unstable nuclei, we have been developing a setup for the transient field experiment at RIKEN Accelerator Research Facility. For the preparation of ferromagnetic material, thick Gd foils have been annealed. In a test experiment using a Ne-22 beam, the projectile Coulomb excitation to the first excited state has been observed.

DOI： 10.1023/a:1020584316404

Magnetic moment and electric quadrupole moment of the N ground state

H. Ogawa, K. Asahi, K. Sakai, A. Yoshimi, M. Tsuda, Y. Uchiyama, T. Suzuki, K. Suzuki, N. Kurokawa, M. Adachi, H. Izumi, H. Ueno, T. Shimoda, S. Tanimoto, N. Takahashi, W.-D. Schmidt-Ott, M. Schäfer, S. Fukuda, A. Yoshida, M. Notani, T. Kubo, H. Okuno, H. Sato, N. Aoi, K. Yoneda, H. Iwasaki, N. Fukuda, N. Fukunishi, M. Ishihara, H. Miyatake

Physics Letters B 451 ( 1-2 ) 11 - 18 1999年4月

Static moments of the N-18 ground state 査読

H Ogawa, K Asahi, K Sakai, A Yoshimi, M Tsuda, Y Uchiyama, T Suzuki, K Suzuki, N Kurokawa, M Adachi, H Izumi, H Ueno, T Shimoda, S Tanimoto, N Takahashi, WD Schmidt-Ott, M Schafer, S Fukuda, A Yoshida, M Notani, T Kubo, H Okuno, H Sato, N Aoi, K Yoneda, H Iwasaki, N Fukuda, N Fukunishi, M Ishihara

JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 24 ( 8 ) 1399 - 1402 1998年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

Nuclear magnetic resonance (NMR) of a radioactive nucleus N-18 has been observed through a change in the beta-ray asymmetry, by taking advantage of the fragment spin polarization in the projectile fragmentation reaction. To facilitate the experiment, a new scheme has been developed which allows assessment of the polarization prior to the resonance search in the beta-ray detected NMR experiment. The obtained magnetic moment /mu/ = 0.3279 +/- 0.0017 mu(N) and the electric quadrupole moment /Q/ = 12.1 +/- 1.2 mb are compared with shell-model calculations.

DOI： 10.1088/0954-3899/24/8/013

Polarized 129Xe solid for polarizing unstable nuclei

H. Sato, M. Tsuda, A. Yoshimi, H. Izumi, H. Ogawa, N. Kurokawa, K. Sakai, M. Adachi, K. Asahi, H. Okuno, T. Kubo, S. Fukuda, A. Yoshida, M. Ishihara, K. Yoneda, M. Notani

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 402 ( 2-3 ) 241 - 243 1998年1月

Observation of parity-violating neutron spin rotation in the n-139La p-wave resonance 査読

K. Sakai, Y. Masuda, T. Adachi, K. Asahi, M. Doi, M. Harada, S. Ishimoto, M. Iinuma, J. Kura, A. Masaike, Y. Matsuda, K. Morimoto, S. Muto, K. Okumura, H. Sato, H.M. Shimizu, A. Yoshimi, Z.J. Zheng

Physics Letters B 391 ( 1-2 ) 11 - 14 1997年1月

Magnetic moments ofN17andB17

H. Ueno, K. Asahi, H. Izumi, K. Nagata, H. Ogawa, A. Yoshimi, H. Sato, M. Adachi, Y. Hori, K. Mochinaga, H. Okuno, N. Aoi, M. Ishihara, A. Yoshida, G. Liu, T. Kubo, N. Fukunishi, T. Shimoda, H. Miyatake, M. Sasaki, T. Shirakura, N. Takahashi, S. Mitsuoka, W.-D. Schmidt-Ott

Physical Review C 53 ( 5 ) 2142 - 2151 1996年5月

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