研究者詳細 - 吉見　彰洋

論文 - 吉見　彰洋

分割表示 148 件中 101 - 120 件目／全件表示 >>

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

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