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Adachi, Tadashi*; Ogawa, Taiki*; Komiyama, Yota*; Sumura, Takuya*; Saito-Tsuboi, Yuki*; Takeuchi, Takaaki*; Mano, Kohei*; Manabe, Kaoru*; Kawabata, Koki*; Imazu, Tsuyoshi*; et al.
Physical Review B, 111(10), p.L100508_1 - L100508_6, 2025/03
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)Yoshida, Masahiro*; Ishii, Kenji; Naka, Makoto*; Ishihara, Sumio*; Jarrige, I.*; Ikeuchi, Kazuhiko*; Murakami, Yoichi*; Kudo, Kazutaka*; Koike, Yoji*; Nagata, Tomoko*; et al.
Scientific Reports (Internet), 6, p.23611_1 - 23611_8, 2016/03
Times Cited Count:1 Percentile:10.59(Multidisciplinary Sciences)Huang, M.*; Haba, Hiromitsu*; Murakami, Masashi*; Asai, Masato; Kaji, Daiya*; Kanaya, Jumpei*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Kikutani, Yuki*; Komori, Yukiko*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 304(2), p.845 - 849, 2015/05
Times Cited Count:3 Percentile:23.54(Chemistry, Analytical)A technique to utilize radioisotopes of Nb and Ta was developed for chemical studies of element 105, Db, by coupling a gas-jet transport system to the RIKEN gas-filled recoil ion separator (GARIS). The short-lived Nb and
Ta were produced with nuclear reactions using a
F beam whose energy was the same as that to produce
Db. Then, they were separated with GARIS and extracted to a chemistry laboratory with the gas-jet transport system. By changing only magnetic field of GARIS and inserting an energy degrader and a shutter for recoil ions, we could deliver the
Nb and
Ta to a chemistry device for
Db without changing other experimental conditions.
Pyon, S.*; Kudo, Kazutaka*; Matsumura, Junichi*; Ishii, Hiroyuki*; Matsuo, Genta*; Nohara, Minoru*; Hojo, Hajime*; Oka, Kengo*; Azuma, Masaki*; Garlea, V. O.*; et al.
Journal of the Physical Society of Japan, 83(9), p.093706_1 - 093706_5, 2014/09
Times Cited Count:35 Percentile:82.26(Physics, Multidisciplinary)Haba, Hiromitsu*; Huang, M.*; Kaji, Daiya*; Kanaya, Jumpei*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Murakami, Masashi*; Ozeki, Kazutaka*; Sakai, Ryutaro*; et al.
Physical Review C, 89(2), p.024618_1 - 024618_11, 2014/02
Times Cited Count:27 Percentile:81.97(Physics, Nuclear)Yoshida, Masahiro*; Ishii, Kenji; Jarrige, I.*; Watanuki, Tetsu; Kudo, Kazutaka*; Koike, Yoji*; Kumagai, Kenichi*; Hiraoka, Nozomu*; Ishii, Hirofumi*; Tsuei, K.-D.*; et al.
Journal of Synchrotron Radiation, 21(1), p.131 - 135, 2014/01
Times Cited Count:3 Percentile:18.05(Instruments & Instrumentation)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:178 Percentile:97.27(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.
Haba, Hiromitsu*; Kaji, Daiya*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozeki, Kazutaka*; Sakai, Ryutaro*; Sumita, Takayuki*; Yoneda, Akira*; Kasamatsu, Yoshitaka*; et al.
Physical Review C, 85(2), p.024611_1 - 024611_11, 2012/02
Times Cited Count:56 Percentile:91.28(Physics, Nuclear)Two isomeric states in Sg, i.e,
Sg
and
Sg
were produced in the
Cm(
Ne,5
) reaction. Decay properties of
Sg
were investigated with a rotating-wheel apparatus for
and spontaneous fission (SF) spectrometry under low background condition attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. Based on genetically correlated
-
(-
) and
-SF decay chains, 18 and 24 events were assigned to
Sg
and
Sg
, respectively. The half-life and
-particle energy of
Sg
were measured to be
s and
MeV, respectively, and those of
Sg
were
s and
MeV.
Sato, Nozomi; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Kaji, Daiya*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozeki, Kazutaka*; Sumita, Takayuki*; Yoneda, Akira*; et al.
Journal of the Physical Society of Japan, 80(9), p.094201_1 - 094201_7, 2011/09
Times Cited Count:16 Percentile:65.66(Physics, Multidisciplinary)Decay properties of Hs and
Hs produced in the
Pb(
Fe,
) [
=1, 2] reactions were studied using a gas-filled recoil ion separator at the linear accelerator facility of RIKEN. A total of 6 decay chains were assigned to
Hs. Cross sections for the
Hs production in the
Pb(
Fe,
) and
Pb(
Fe,
) reactions were measured to be
pb and
pb, respectively. The isotope
Hs decayed with a half-life of
ms by
-particle emission and spontaneous fission. The
-particle energy of
Hs was observed at 10.61
0.04 and 10.80
0.08 MeV. The spontaneous fission branch of
Hs was found to be
.
Yoshida, Masahiro; Ishii, Kenji; Ikeuchi, Kazuhiko*; Jarrige, I.; Murakami, Yoichi*; Mizuki, Junichiro; Tsutsui, Kenji; Toyama, Takami*; Maekawa, Sadamichi*; Kudo, Kazutaka*; et al.
Physica C, 470(Suppl.1), p.S145 - S146, 2010/12
Times Cited Count:4 Percentile:20.87(Physics, Applied)Wakimoto, Shuichi; Hiraka, Haruhiro*; Kudo, Kazutaka*; Okamoto, Daichi*; Nishizaki, Terukazu*; Kakurai, Kazuhisa; Hong, T.*; Zheludev, A.*; Tranquada, J. M.*; Kobayashi, Norio*; et al.
Physical Review B, 82(6), p.064507_1 - 064507_7, 2010/08
Times Cited Count:8 Percentile:36.06(Materials Science, Multidisciplinary)no abstracts in English
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:77.51(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.
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; et al.
Journal of the Physical Society of Japan, 78(3), p.035003_1 - 035003_2, 2009/03
Times Cited Count:3 Percentile:25.59(Physics, Multidisciplinary)A new neutron deficient hassium (=108) isotope of
Hs was identified via two different reactions of
Pb(
Fe,n) and
Pb(
Fe,n) by using a gas-filled recoil separator GARIS at June 2008. During the 25-h irradiation of
Pb with the
Fe beam and 46-h irradiation of
Pb with the
Fe beam, 8 decay chains and 1 decay chain, respectively, have been observed. The half-life of
Hs is 0.60
ms. In this experiment, the total beam doses of the Fe and
Fe was 4.1
10
ions and 6.2
10
ions, respectively. The production cross sections corresponding to the 8 decay chains and 1 decay chain have been deduced to be 21
pb and 1.6
pb by assuming the transmission of the system to be 80%.
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; et al.
Journal of the Physical Society of Japan, 78(3), p.035003_1 - 035003_2, 2009/03
A new hassium isotopes Hs is directly produced for the first time. The experiment was performed at the linear accelerator (RILAC) facility in RIKEN (the Institute of Physical and Chemical Research) from Jun. 19 to 25. In the 25-h irradiation of
Fe on
Pb and 46-h irradiation of
Fe on
Pb, 8 decay chains and 1 decay chain, respectively, were observed. All decay chains were assigned to subsequent decays from
Hs. The half-life of
Hs is 0.60
ms. In this experiment, the total beam dose was
ions for
Fe and
ions for
Fe. The production cross section corresponding to 8 decay events and 1 decay chain was deduced to be 21
pb and 1.6
pb by assuming that the transmission of the system is 80%.
Sato, Nozomi*; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Kaji, Daiya*; Koura, Hiroyuki; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozawa, Akira*; et al.
RIKEN Accelerator Progress Report, Vol.42, P. 16, 2009/00
New Decay Properties of Hs and its
-decay daughter nuclei were studied by using reactions of
Pb(
Fe,2n) and
Pb(
Fe,n) by using a gas-filled recoil ion separator, GARIS at RIKEN. We observed three correlated events in irradiation of
Fe on
Pb, and eight events in irradiation of
Fe on
Pb. A half-life was deduced to be 0.90
. We assigned these eleven events to be the decays of
Hs. We found different decay-chain events of
Hs from a previous report. One is a long-lived
-decay of
Sg with 180
ms of half-life. Another is a long-lived
-decay of
Rf with 10.4
s of half-life. For
Sg and
Rf, the decay of such a long-lived state have not been reported. These are the first observations of isomerism in
Sg and
Rf.
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.
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi*; Endo, Yasuo*; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; et al.
Physical Review B, 76(4), p.045124_1 - 045124_7, 2007/07
Times Cited Count:20 Percentile:62.43(Materials Science, Multidisciplinary)(La,Sr,Ca)Cu
O
is an attractive material in connection with high-
superconductivity because Sr
Ca
Cu
O
becomes a superconductor under high pressure without the CuO
planes. We present RIXS at the Cu
-edge of (La,Sr,Ca)
Cu
O
focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.
Matsuda, Masaaki; Kakurai, Kazuhisa; Kurogi, Shogo*; Kudo, Kazutaka*; Koike, Yoji*; Yamaguchi, Hirotaka*; Ito, Toshimitsu*; Oka, Kunihiko*
Physical Review B, 71(10), p.104414_1 - 104414_8, 2005/03
Times Cited Count:13 Percentile:48.94(Materials Science, Multidisciplinary)no abstracts in English
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; Ozeki, Kazutaka*; et al.
no journal, ,
A new neutron deficient hassium () isotope of
Hs was identified via two different reactions of
Pb(
Fe,
) and
Pb(
Fe,
) by using the gas-filled recoil separator GARIS. During irradiation of
Pb with the
Fe beam and irradiation of
Pb with the
Fe beam, 8 decay chains and 1 decay chain, respectively, were observed. The properties of decay events obtained by irradiation of
Fe on
Pb match well with those by irradiation of
Fe on
Pb. The mean
-decay energies for the 3 groups are 10.82, 10.55, and 10.37 MeV, respectively. The half-life of
Hs is determined to be 0.60 ms.
Haba, Hiromitsu*; Oe, Kazuhiro*; Ozeki, Kazutaka*; Kasamatsu, Yoshitaka*; Kaji, Daiya*; Kudo, Yuki*; Komori, Yukiko*; Sato, Nozomi; Shinohara, Atsushi*; Morita, Kosuke*; et al.
no journal, ,
A gas-jet transport system for superheavy element chemistry has been coupled to the gas-filled recoil ion separator GARIS at the RIKEN linear accelerator. In this work, we have investigated the performance of the system using Rf produced in the
Cm(
O,5
)
Rf reaction. The present result demonstrates that the GARIS/gas-jet system is a promising approach to explore new frontiers in SHE chemistry: (1) the background radioactivities originating from unwanted reaction products are strongly suppressed, (2) the intense primary heavy-ion beam is absent in the gas-jet chamber, and hence high gas-jet transport efficiency is achieved, and (3) the beam-free conditions also make it possible to investigate new chemical systems that were not accessible before.