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Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count:14 Percentile:71.67(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the Ca +
Pb,
Ti +
Pb, and
Ca +
Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the
Ca +
Pb and
Ti +
Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the
Ca +
Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Ariga, Hirotake*; Katori, Taku*; Yoshihara, Ryohei*; Hase, Yoshihiro; Nozawa, Shigeki; Narumi, Issei; Iuchi, Satoshi*; Kobayashi, Masatomo*; Tezuka, Kenji*; Sakata, Yoichi*; et al.
Plant Signaling & Behavior (Internet), 8(7), p.e24779_1 - e24779_5, 2013/07
Based on analysis of the salinity tolerance among 354 accessions, some accessions showed greater salt shock tolerance compared with a reference accession, Col-0 on a typical assay with drastic change in NaCl concentration from 0 mM to 225 mM. On the other hand, several accessions including Zu-0 exhibited marked acquired salt tolerance, which is induced after exposure to moderate salt stress (salt acclimation ability). It is likely that Arabidopsis plants have at least two types of tolerance abilities, salt shock tolerance and salt acclimation. To dissect the salt tolerance mechanisms of the salt tolerant accessions, we isolated a salt-sensitive mutant from ion beam-mutagenized Zu-0 seedlings. The mutant showed severe growth inhibition under salt shock stress due to a single base deletion in SOS1 gene as well-known salt shock tolerance gene, even more salt sensitive than Col-0. Nevertheless, the mutant was able to survive on the salt acclimation with 100 mM NaCl for 7 days followed with 750 mM sorbitol for 20 days (salt acclimation assay) as well as the Zu-0 wild type, whereas Col-0 showed apparent chlorosis under the condition. We propose that a gene for salt acclimation ability is different from a gene for salt shock tolerance and plays an important role in acquisition for marked salt- or osmotic tolerance.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.
Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10
Times Cited Count:157 Percentile:97.26(Physics, Multidisciplinary)An isotope of the 113th element, 113, was produced in a nuclear reaction with a
Zn beam on a
Bi target. We observed six consecutive
decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of
Db and
Lr both in decay energies and decay times. This indicates that the present decay chain consisted of
113,
Rg (Z = 111),
Mt (Z = 109),
Bh (Z = 107),
Db (Z = 105), and
Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope
113, of the 113th element.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi*; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.
Journal of the Physical Society of Japan, 78(6), p.064201_1 - 064201_6, 2009/06
Times Cited Count:30 Percentile:78.96(Physics, Multidisciplinary)Decay properties of an isotope Bh and its daughter nucleus
Db produced by the
Cm(
Na,5
) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector.
Bh was clearly identified from the correlation of the known nuclide,
Db. The obtained decay properties of
Bh and
Db are consistent with those observed in the
113 chain, which provided further confirmation of the discovery of
113.
Morimoto, Koji*; Morita, Kosuke*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Katori, Kenji*; Koura, Hiroyuki; Kudo, Hisaaki*; et al.
RIKEN Accelerator Progress Report, Vol.42, P. 15, 2009/00
In 2003-2007, we had performed an experiment to synthesize an element 113 by a Bi
Zn reaction using a gas-filled recoil ion separator (GARIS) at RIKEN Nishina-Center. In a total of 241 days of net irradiation time experiment, two decay chains were observed and assigned from an isotope
113. The cross section of the
Bi(
Zn,n)
113 reaction was determined to be 31
fb at that time. In order to increase the statistics of the decay property, we continued to produce more decay chains. The experiment was carried out from January 7 to March 31, 2008. The experimental conditions were identical to those used in the previous experiment.
Zn ion beam of 353 MeV was extracted from RILAC. The net irradiation time was 83 days and the total dose of
Zn was 2.28
. In the present expriment any candidate of
113 was not observed. Then combining the results of the present and previous experiments, the production cross section of
113 was determined to be 22
fb.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Katori, Kenji*; Koura, Hiroyuki; Kudo, Hisaaki*; et al.
Journal of the Physical Society of Japan, 76(4), p.043201_1 - 043201_5, 2007/04
Times Cited Count:147 Percentile:96.01(Physics, Multidisciplinary)The production and decay of 112 has been investigated using a gas-filled recoil ion separator in irradiations of
Pb targets with
Zn beam at 349.5 MeV. We have observed two
-decay chains that can be assigned to subsequent decays from
112 produced in the 208 Pb(
Zn,n) reaction. After emitting four consecutive
-particles, the both chains ended by spontaneous fission decays of
Rf and decay energies and decay times of the both chains obtained in the present work agree well with those reported by a group at Gesellschaft f
r Schwerionenforschung (GSI), Germany. The present result gives the first clear confirmation of the discovery of
112 and its
-decay products
Ds reported previously.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Katori, Kenji*; Koura, Hiroyuki; Kikunaga, Hidetoshi*; et al.
Journal of the Physical Society of Japan, 76(4), p.045001_1 - 045001_2, 2007/04
Times Cited Count:192 Percentile:97.38(Physics, Multidisciplinary)The production and decay of 113 has been investigated using a gas-filled recoil ion separator in irradiations of
Bi targets with
Zn beam at 353 MeV. We have observed one
-decay chain that can be assigned to subsequent decays from
113 produced in the
Bi(
Zn,n) reaction. After emitting four consecutive
-particles, the both chains ended by spontaneous fission decays of
Db and decay energies and decay times of the both chains obtained in the present work agree well with those reported by our group in 2004. The present result gives the first clear confirmation of the discovery of
113 and its
-decay products
Rg reported previously.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Kanungo, R.*; Katori, Kenji*; Kikunaga, Hidetoshi*; et al.
AIP Conference Proceedings 891, p.3 - 9, 2007/03
A series of experiments studying the productions and their decays of the heaviest elements have been performed by using a gas-filled recoil separator GARIS at RIKEN. Results on the isotope of the 112th element, 112, and on that of the 113th element,
113, are reviewed. Two decay chains which are assigned to be ones originating from the isotope
112 were observed in the
Pb(
Zn, n) reaction. The results provide a confirmation of the production and decay of the isotope
112 reported by a research group at GSI, Germany, produced via the same reaction by using a velocity filter. Two decay chains, both consisted of four consecutive alpha decays followed by a spontaneous fission, were observed also in the reaction
Bi(
Zn, n). Those are assigned to be the convincing candidate events of the isotope of the 113th element,
113, and its daughter nuclei.
Rg,
Mt,
Bh, and
Db.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Kanungo, R.*; Katori, Kenji*; Koura, Hiroyuki; et al.
Journal of the Physical Society of Japan, 73(10), p.2593 - 2596, 2004/10
Times Cited Count:475 Percentile:99.23(Physics, Multidisciplinary)The isotope of the 113th element, 113, and its daughter nuclei,
111 and
Mt, were obserbed, for the first time, in the
Bi +
Zn reaction at a beam energy of 349.1 MeV with a total dose of 1.6
10
. The production cross section of
113 is deduced to be
fb (
cm
).
Inoue, Kazuhiko; Katori, Kenji*
JAERI 1041, 16 Pages, 1962/12
no abstracts in English
Morimoto, Koji*; Morita, Kosuke*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.
no journal, ,
A nuclide, Bh, is the great-grand-daughter of
113 that is produced in the
Bi +
Zn reaction. The identification was based on a genetic link to the known daughter nucleus
Db by alpha-decays. The main purpose of this work is to provide further confirmation of the production and identification of the isotope
113. As a present result, a state in
Bh, which decays by an alpha emission with the energies ranging from 9.05 to 9.23 MeV, feeds a state in
Db, which decays by alpha emission and by SF with a previously known half-life. The result provided a further confirmation of the production and identification of the isotope of the 113th element,
113, studied by a research group at RIKEN.
Morimoto, Koji*; Morita, Kosuke*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.
no journal, ,
no abstracts in English
Morimoto, Koji*; Morita, Kosuke*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.
no journal, ,
We performed the experiment to synthesize an isotope of the element 113 produced by a Bi(
Zn,n)
113 reaction using a gas-filled recoil ion separator (GARIS) at RIKEN. Two decay chains were observed, and assigned to those originating from an isotope
113. Both chains were connected into the previously known decays of
Bh and
Db via previously unknown decays of
113,
Rg, and
Mt. Although the
Bh was known nuclide, a number of atoms reported so far was limited. In order to study more precise decay property of the
Bh, we performed the direct production of
Bh by the
Cm(
Na,5n)
Bh reaction. In this experiment, the
Bh was clearly identified from the correlation of the nuclide,
Db. The obtained decay properties of
Bh and
Db are consistent with those observed in the
113 chain, which provided further confirmation of the discovery of
113.
Sumita, Takayuki*; Morimoto, Koji*; Kaji, Daiya*; Ozeki, Kazutaka*; Katori, Kenji*; Sakai, Ryutaro*; Hasebe, Hiroo*; Haba, Hiromitsu*; Yoneda, Akira*; Yoshida, Atsushi*; et al.
no journal, ,
The decay property of Cn (atomic number,
) produced in the
Pb(
Zn,
) reaction was studied. The experiment was performed using the gas-filled recoil ion separator (GARIS) at the RIKEN liner accelerator facility (RILAC). The
Pb target with about 630
g/cm
thickness was bombarded with 347.5, 351.5, and 355.5 MeV
Zn beam. At the beam energy of 351.5 MeV, we observed one
-decay chain from
Cn. The
-particle energy of
Cn was
MeV and its lifetime was measured to be 0.370 ms. Including our previous result of the
Cn production in 2004, the cross section of the
Pb(
Zn,
) reaction is deduced to be
pb.
Hanamuro, Takahiro; Takatori, Ryoichi; Yasue, Kenichi; Shibata, Kenji; Umeda, Koji
no journal, ,
no abstracts in English
Hanamuro, Takahiro; Yasue, Kenichi; Shibata, Kenji; Umeda, Koji; Takatori, Ryoichi*
no journal, ,
Petrographical and geochemical approaches were adopted by samples of the Inagawa Granite and Naegi-Agematsu Granite, distributed along upper river basin of Toki River. And gravel from upper layer of these rock bodies were investigated for identification of granitic rock bodies. Petrographic feature of these rock bodies are distinguished by hornblende or muscovite contents. Major element analyses of biotites by EPMA showed the samples from the Naegi-Agematsu Granite were rich in Fe relative to those from the Inagawa Granite. By using this method, the gravel from upper layer of these rock bodies is suggested to be from the Naegi-Agematsu Granite area. Therefore, chemical composition of biotite suggests good indicator for hinterland analysis in this case.