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Takahashi, Ryuta; Ishii, Tetsuro; Asai, Masato; Nagae, Daisuke*; Makii, Hiroyuki; Tsukada, Kazuaki; Toyoshima, Atsushi; Ishii, Yasuo; Matsuda, Makoto; Makishima, Akiyasu*; et al.
Physical Review C, 81(5), p.057303_1 - 057303_4, 2010/05
Times Cited Count:13 Percentile:62.99(Physics, Nuclear)The ground-state bands of Cf have been established up to 10, 12, and 10 states, respectively, by in-beam -ray spectroscopy using neutron-transfer reactions with a O beam and a highly radioactive Cf target. The deexcitation rays in Cf were identified by taking coincidences with outgoing particles of O measured with Si - detectors, and by selecting their kinetic energies. This is the first in-beam -ray spectroscopy for Cf isotopes.
Ishii, Tetsuro; Makii, Hiroyuki*; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shigematsu, Soichiro*; Kaneko, Junichi*; Shizuma, Toshiyuki; et al.
Physical Review C, 78(5), p.054309_1 - 054309_11, 2008/11
Times Cited Count:14 Percentile:64.80(Physics, Nuclear)Ishii, Tetsuro; Makii, Hiroyuki; Asai, Masato; Koura, Hiroyuki; Shigematsu, Soichiro*; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; et al.
Nuclear Physics A, 805(1-4), p.257 - 259, 2008/06
no abstracts in English
Makii, Hiroyuki; Ishii, Tetsuro; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Kaneko, Junichi*; Tome, Hayato*; Ichikawa, Shinichi; et al.
Physical Review C, 76(6), p.061301_1 - 061301_5, 2007/12
Times Cited Count:28 Percentile:83.33(Physics, Nuclear)We have measured deexcitation rays for the first time in the neutron-rich nuclei of Pu and Pu produced by the (O, O) and the (O, O) reactions, respectively. The ground-state band of Pu was established up to 12 states. The systematics of the moments of inertia of Pu isotopes suggests that the deformed subshell closure disappears in these isotopes. The measurements of deexcitation rays in Pu shows a small energy spacing between neutron orbitals at , which explans the disappearance of the subshell closure.
Ishii, Tetsuro; Shigematsu, Soichiro*; Makii, Hiroyuki; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; Kaneko, Junichi*; et al.
Physics of Atomic Nuclei, 70(8), p.1457 - 1461, 2007/08
Times Cited Count:9 Percentile:56.22(Physics, Nuclear)We have measured deexcitation rays in the neutron-rich nuclei of U, Pu and Cm. These nuclei were produced by the (O, O) two-neutron transfer reactions with a 200, 162 and 162 MeV O beams and a U, Pu and Cm targets, respectively, using the tandem accelerator at Tokai, Japan. The rays in residual nuclei were measured by taking coincidence with scattering particles using Si - detectors. We have identified rays in U, Pu and Cm by selecting the kinetic energies of O particles which correspond to the excitation energies in these nuclei below their neutron separation energies. The ground-state bands of U, Pu and Cm were established up to 12 states and the octupole band of U was established up to 9 state. Because the deformations of these nuclei are well developed, the moments of inertia reflect the pairing gap, which is expected to be smaller, resulting in a larger moment of inertia, at the deformed shell closure. We have found that the moment of inertia of the ground-state band of Cm is considerably larger than that of Cm. This fact supports the existence of the deformed subshell closure at in Cm isotopes. On the other hand, the moment of inertia of Pu was found to be smaller than that of Pu, which suggests that the deformed subshell closure at weakens or disappears in Pu isotopes. These results are consistent with the prediction by a cranking model calculation.
Ishii, Tetsuro; Makii, Hiroyuki; Asai, Masato; Koura, Hiroyuki; Shigematsu, Soichiro*; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Kaneko, Junichi*; et al.
Physical Review C, 76(1), p.011303_1 - 011303_5, 2007/07
Times Cited Count:14 Percentile:67.70(Physics, Nuclear)The ground-state bands of the neutron-rich Th and U nuclei were established up to spin 10 and 8, respectively, by in-beam -ray spectroscopy using the (O, Ne) two-proton pickup reaction with a U and a Pu target. Deexcitation rays in Th and U were identified by selecting the kinetic energies of Ne using Si - detectors. The excitation energies of the first 2 states in U and Pu isotopes have local minima at , suggesting the possibility that nuclei with have a spherical shell closure of . Calculation using the Koura-Yamada single-particle potential gives an energy gap of 1.8 MeV at for U.
Ishii, Tetsuro; Shigematsu, Soichiro; Makii, Hiroyuki; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; Kaneko, Junichi*; et al.
Journal of the Physical Society of Japan, 75(4), p.043201_1 - 043201_4, 2006/04
Times Cited Count:19 Percentile:68.29(Physics, Multidisciplinary)The ground-state band of the neutron-rich transuranium nucleus Cm was established up to spin 12 by in-beam -ray spectroscopy using the two-neutron-transfer reaction with a Cm target and a 162 MeV O beam. Deexcitation rays in Cm were identified by selecting the kinetic energies of O particles with Si - detectors. The moment of inertia of Cm is considerably smaller than that of Cm, which supports the existence of the deformed subshell closure at in Cm isotopes.
Ishii, Tetsuro; Shigematsu, Soichiro; Asai, Masato; Makishima, Akiyasu*; Matsuda, Makoto; Kaneko, Junichi*; Hossain, I.*; Ichikawa, Shinichi; Kono, Toshiyuki*; Ogawa, Masao*
Physical Review C, 72(2), p.021301_1 - 021301_5, 2005/08
Times Cited Count:20 Percentile:76.26(Physics, Nuclear)In the two-neutron-transfer reaction of a 200-MeV O beam with a U target, deexcitation rays in a neutron-rich nucleus of U were measured. The rays in U were identified by taking coincidence with O, using Si - detectors. The kinetic energies of O particles allowed us to select the excitation energies of U below the neutron separation energy. The ground-state band and the octupole band of U were established up to 12 and 9, respectively. The octupole-band head of U is higher than those of U by about a hundred keV, suggesting that a secondary maximum of octupole correlations exists at in U isotopes.
Asai, Masato; Ishii, Tetsuro; Makishima, Akiyasu*; Ogawa, Masao*; Matsuda, Makoto
Fission and Properties of Neutron-Rich Nuclei; Proceedings of 3rd International Conference, p.295 - 297, 2003/10
Nanosecond isomers in neutron-rich N20 nuclei produced in the heavy-ion deep-inelastic collision have been searched for. Spin-parities of the isomers in Si and P have been identified through -ray angular distribution and lifetime measurements. It has been found that these isomers arise from the neutron excitation on the orbitals.
Ishii, Tetsuro; Asai, Masato; Makishima, Akiyasu*; Hossain, I.*; Kleinheinz, P.*; Ogawa, Masao*; Matsuda, Makoto; Ichikawa, Shinichi
European Physical Journal A, 13(1-2), p.15 - 19, 2002/01
no abstracts in English
Ishii, Tetsuro; Asai, Masato; Matsuda, Makoto; Ichikawa, Shinichi; Makishima, Akiyasu*; Hossain, I.*; Kleinheinz, P.*; Ogawa, Masao*
Acta Physica Polonica B, 32(3), p.739 - 746, 2001/03
no abstracts in English
Asai, Masato; Ishii, Tetsuro; Makishima, Akiyasu*; Hossain, I.*; Ogawa, Masao*; Ichikawa, Shinichi
Physical Review C, 62(5), p.054313_1 - 054313_7, 2000/11
Times Cited Count:19 Percentile:69.09(Physics, Nuclear)no abstracts in English
Ishii, Tetsuro; Asai, Masato*; Makishima, Akiyasu*; Hossain, I.*; Ogawa, Masao*; Hasegawa, Jun*; Matsuda, Makoto*; Ichikawa, Shinichi
AIP Conference Proceedings 495, p.67 - 70, 1999/12
no abstracts in English
Ishii, Tetsuro; Asai, Masato*; Hossain, I.*; P.Kleinheinz*; Ogawa, Masao*; Makishima, Akiyasu*; Ichikawa, Shinichi; ; ; J.Blomqvist*
Physical Review Letters, 81(19), p.4100 - 4103, 1998/11
Times Cited Count:43 Percentile:83.06(Physics, Multidisciplinary)no abstracts in English
Ishii, Tetsuro; ; ; Makishima, Akiyasu*; Hossain, I.*; Hayakawa, Takehito*; Kono, Toshiyuki*; Ogawa, Masao*
Nuclear Instruments and Methods in Physics Research A, 395(2), p.210 - 216, 1997/00
Times Cited Count:41 Percentile:92.53(Instruments & Instrumentation)no abstracts in English
; Ishii, Tetsuro; Makishima, Akiyasu*; Ogawa, Masao*; ;
5th Int. Spring Seminar on Nuclear Physics,New Perspectives in Nuclear Structure, 0, p.159 - 168, 1995/00
no abstracts in English
; Ishii, Tetsuro; Makishima, Akiyasu*; Ogawa, Masao*; ;
Phys. Scr., T56, p.89 - 93, 1995/00
Times Cited Count:9 Percentile:55.72(Physics, Multidisciplinary)no abstracts in English
Ogawa, Masao*; ; Makishima, Akiyasu*; Ishii, Tetsuro; ; ;
Phys. Scr., T56, p.289 - 291, 1995/00
Times Cited Count:2 Percentile:26.04(Physics, Multidisciplinary)no abstracts in English
Ogawa, Masao*; ; Makishima, Akiyasu*; Ishii, Tetsuro; ; ;
Phys. Scr., T56(0), p.289 - 291, 1995/00
no abstracts in English
Ishii, Tetsuro; Makishima, Akiyasu*; Shibata, Michihiro; Ogawa, Masao*;
Physical Review C, 49(6), p.2982 - 2989, 1994/06
Times Cited Count:12 Percentile:61.79(Physics, Nuclear)no abstracts in English