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Br using the CCONE-based calculation systemSakai, Seiya*; Otsu, Hideaki*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Nakayama, Shinsuke; Fukahori, Tokio; Kikunaga, Hidetoshi*; Yokokita, Takuya*
RIKEN Accelerator Progress Report, Vol.58, P. 54, 2025/12
Sakai, Seiya*; Otsu, Hideaki*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Nakayama, Shinsuke; Kikunaga, Hidetoshi*; Fukahori, Tokio
RIKEN Accelerator Progress Report, Vol.58, P. 55, 2025/12
Cu and
Cu with accelerator neutrons by deuterons and their separation from zincNagai, Yasuki*; Kawabata, Masako*; Saeki, Hideya*; Motoishi, Shoji*; Hashimoto, Kazuyuki; Tsukada, Kazuaki; Motomura, Arata*; Ota, Akio*; Takashima, Naoki*; Hashimoto, Shintaro; et al.
Frontiers in Nuclear Medicine (Internet), 5, p.1657125_1 - 1657125_11, 2025/10
In recent years, the radionuclide pair of
Cu and
Cu has attracted attention as an ideal theranostic agent. We proposed a novel production method utilizing a neutron source generated by deuteron beams at an accelerator facility. By irradiating enriched
Zn samples with this neutron source, we measured the absolute activity and radionuclidic purity of the produced
Cu. The results were consistent with calculations performed using PHITS and JENDL-5 developed by the Japan Atomic Energy Agency, confirming the reliability of the calculation method and demonstrating its capability to estimate the yields of trace radionuclides that are difficult to measure experimentally. Furthermore, we successfully separated
Cu from the irradiated Zn sample using our developed sublimation and column separation techniques. These findings suggest that the production of
Cu and
Cu can be achieved in an economically sustainable manner at multiple sites.
Kaneda, Kazuko*; Shirakami, Yoshifumi*; Kadonaga, Yuichiro*; Watabe, Tadashi*; Oe, Kazuhiro*; Yin, X.*; Haba, Hiromitsu*; Shirasaki, Kenji*; Kikunaga, Hidetoshi*; Tsukada, Kazuaki; et al.
International Journal of Molecular Sciences (Internet), 25(2), p.933_1 - 933_14, 2024/01
Times Cited Count:9 Percentile:80.45(Biochemistry & Molecular Biology)
-ray measurements of the
Th isomerMuramatsu, Haruka*; Hayashi, Tasuku*; Yuasa, Naoki*; Konno, Ryohei*; Yamaguchi, Atsushi*; Mitsuda, Kazuhisa*; Yamasaki, Noriko*; Maehata, Keisuke*; Kikunaga, Hidetoshi*; Takimoto, Misaki; et al.
Journal of Low Temperature Physics, 200(5-6), p.452 - 460, 2020/09
Times Cited Count:2 Percentile:8.18(Physics, Applied)
Bh in the
Cm(
Na,5
)
Bh reaction and its decay propertiesHaba, Hiromitsu*; Fan, F.*; Kaji, Daiya*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Komori, Yukiko*; Kondo, Narumi*; Kudo, Hisaaki*; Morimoto, Koji*; Morita, Kosuke*; et al.
Physical Review C, 102(2), p.024625_1 - 024625_12, 2020/08
Times Cited Count:8 Percentile:55.59(Physics, Nuclear)
Th nuclear clock isomer determined by absolute
-ray energy differenceYamaguchi, Atsushi*; Muramatsu, Haruka*; Hayashi, Tasuku*; Yuasa, Naoki*; Nakamura, Keisuke; Takimoto, Misaki; Haba, Hiromitsu*; Konashi, Kenji*; Watanabe, Makoto*; Kikunaga, Hidetoshi*; et al.
Physical Review Letters, 123(22), p.222501_1 - 222501_6, 2019/11
Times Cited Count:58 Percentile:91.26(Physics, Multidisciplinary)
acidic solutionsYokoyama, Akihiko*; Kitayama, Yuta*; Fukuda, Yoshiki*; Kikunaga, Hidetoshi*; Murakami, Masashi*; Komori, Yukiko*; Yano, Shinya*; Haba, Hiromitsu*; Tsukada, Kazuaki; Toyoshima, Atsushi*
Radiochimica Acta, 107(1), p.27 - 32, 2019/01
Times Cited Count:1 Percentile:7.90(Chemistry, Inorganic & Nuclear)Kaji, Daiya*; Morimoto, Koji*; Wakabayashi, Yasuo*; Takeyama, Mirei*; Yamaki, Sayaka*; Tanaka, Kengo*; Haba, Hiromitsu*; Huang, M.*; Murakami, Masashi*; Kanaya, Jumpei*; et al.
JPS Conference Proceedings (Internet), 6, p.030107_1 - 030107_4, 2015/06
Performance of the new gas-filled recoil ion separator GARIS-II was investigated using asymmetric
Ne-induced fusion reactions. The use of He-H
mixture gas for the gas-filled magnet significantly reduced background scattered particles detected at the focal-plane Si detector, and increased a transmission of the asymmetric reaction products. A target-identification system was newly installed for efficient measurements of excitation functions without changing beam energy nor target.
Nb and
Ta for chemical studies of element 105, Db, using the GARIS gas-jet systemHuang, 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:22.35(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.
Lr in the
Cf +
B,
Am +
O, and
Cm +
N reactionsSato, Nozomi; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Tsukada, Kazuaki; Li, Z.*; Nishio, Katsuhisa; Nagame, Yuichiro; Sch
del, M.; Haba, Hiromitsu*; et al.
Radiochimica Acta, 102(3), p.211 - 219, 2014/03
Times Cited Count:11 Percentile:59.26(Chemistry, Inorganic & Nuclear)Production cross-sections of the isotope
Lr in the
Cf +
B,
Am +
O, and
Cm +
N reactions were measured using a He/KCl gas-jet transport system and a rotating wheel
-particle detection apparatus. The
-particle energy of
Lr was distributed from 8.3 to 8.7 MeV and its half-life,
, was measured to be
s. The maximum cross sections in the
Cf(
B, 4
)
Lr and
Am(
O, 5
)
Lr reactions were determined to be
nb at the beam energy of 63 MeV and
nb at 96 MeV, respectively. In the
Cm(
N, 6
)
Lr reaction, the cross section was measured to be
nb at 91 MeV.
Db in the
Cm(
F,5
)
Db reaction and decay properties of
Db and
LrHaba, 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:32 Percentile:83.95(Physics, Nuclear)
Cm +
O reactionMurakami, Masashi*; Goto, Shinichi*; Murayama, Hirofumi*; Kojima, Takayuki*; Kudo, Hisaaki*; Kaji, Daiya*; Morimoto, Koji*; Haba, Hiromitsu*; Kudo, Yuki*; Sumita, Takayuki*; et al.
Physical Review C, 88(2), p.024618_1 - 024618_8, 2013/08
Times Cited Count:23 Percentile:74.23(Physics, Nuclear)Production cross sections of Rf isotopes in the
Cm +
O reaction were measured at the beam energy range of 88.2 to 101.3 MeV by use of a gas-filled recoil ion separator. The excitation functions of
Rf,
Rf, and
Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to
Rf and a longer-lived state of
Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the
O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of
Rf, whereas it was quite different from those of
Rf and
Rf. A few-second spontaneously fissioning nuclide previously reported as
Rf and
Rf observed in
Cm +
O reaction was identified as
Rf.
Lr in the
Cm +
N reactionSato, Nozomi; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Tsukada, Kazuaki; Li, Z.*; Nishio, Katsuhisa; Nagame, Yuichiro; Sch
del, M.; Haba, Hiromitsu*; et al.
RIKEN Accelerator Progress Report, Vol.46, P. 237, 2013/00
Due to the strong relativistic effects, the weakly-bound outermost electron results in a significantly low first ionization potential (IP) of Lr as compared with its neighboring heavy actinides. The isotope
Lr, with a relatively long half-life of 27 s, is the suitable candidates for the IP measurement of Lr through the surface ionization method. In the present study, we measured the cross section of the
Cm(
N, 6
)
Lr reaction to evaluate the production rate of
Lr. A
Cm target with 960
60
g/cm
thickness was bombarded with a
N
beam from the RIKEN AVF Cyclotron. The beam energy was 91 MeV in the middle of the target. The average beam intensity was 1.2 particle-
A. Reaction products were transported to the rotating wheel
-particle detection system with a He/KCl gas-jet system. The
Lr cross section of 27
1 nb was calculated based on the
-particle events between 8.3 and 8.7 MeV.
113 of the 113th elementMorita, 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:184 Percentile:97.12(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.
Sg in the
Cm(
Ne,5
)
Sg reaction and decay properties of two isomeric states in
SgHaba, 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:60 Percentile:91.06(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.
Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.
Chemistry Letters, 38(11), p.1084 - 1085, 2009/10
Times Cited Count:18 Percentile:50.35(Chemistry, Multidisciplinary)We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO
solution at the fluoride ion concentration [F
] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.
Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.
Radiochimica Acta, 97(2), p.83 - 89, 2009/02
Times Cited Count:22 Percentile:77.97(Chemistry, Inorganic & Nuclear)Anion-exchange chromatography of element 105, dubnium (Db), produced in the
Cm(
F, 5n)
Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K
) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta
Nb
Db
Pa.
Haba, Hiromitsu*; Akiyama, Takahiro*; Kaji, Daiya*; Kikunaga, Hidetoshi*; Kuribayashi, Takahiro*; Morimoto, Koji*; Morita, Kosuke*; Oe, Kazuhiro*; Sato, Nozomi*; Shinohara, Atsushi*; et al.
European Physical Journal D, 45(1), p.81 - 86, 2007/10
Times Cited Count:14 Percentile:53.09(Optics)A review is given on the startup of the superheavy element (SHE) chemistry at RIKEN. A gas-jet transport system for the SHE chemistry has been coupled to the gas-filled recoil ion separator GARIS at the RIKEN Linear Accelerator. The performance of the system was appraised using
Fr and
Fm produced in the
Tm(
Ar,3
)
Fr and
Pb(
Ar,3
)
Fm reactions, respectively. The
particles of
Fr and
Fm separated with GARIS and transported by the gas-jet were identified with a rotating wheel system for
spectrometry under desired low background condition. The high gas-jet efficiencies over 80% were independent of the beam intensities up to 2 particle
A. A gas-jet coupled target system for the production of SHEs was also installed on the beam line of the RIKEN K70 AVF cyclotron. The gas-jet transport of
No and
Rf produced in the
U(
Ne,5
)
No and
Cm(
O,5
)
Rf reactions, respectively, was conducted for the future chemical studies of
Sg via the
Cm(
Ne, 5
)
Sg reaction.
113Morita, 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:214 Percentile:97.34(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.