研究者詳細 - 吉見　彰洋

論文 - 吉見　彰洋

分割表示 148 件中 121 - 140 件目／全件表示 >>

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.

　前のページ - 次のページ　

1
2
3
4
5
6
7
8