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Yuguchi, Takashi*; Yamazaki, Hayato*; Ishibashi, Kozue*; Sakata, Shuhei*; Yokoyama, Tatsunori; Suzuki, Satoshi*; Ogita, Yasuhiro; Sando, Kazusa*; Imura, Takumi*; Ono, Takeshi*
Journal of Asian Earth Sciences, 226, p.105075_1 - 105075_9, 2022/04
Times Cited Count:4 Percentile:54.83(Geosciences, Multidisciplinary)Simultaneous determination of the U-Pb age of zircon and concentration of titanium in a single analysis spot, using inductively coupled plasma mass spectrometry with laser ablation sample introduction, produces paired age and temperature data of zircon crystallisation, potentially revealing time-temperature () histories for evolved magma. The Kurobegawa granite, central Japan, contains abundant mafic magmatic enclaves (MMEs). We applied this method to evaluate MMEs and their host (enclosing) granites. Cooling behaviour common to both MMEs and host rocks was found between 1.5 and 0.5 Ma. Rapid cooling from the zircon crystallisation temperature to the closure temperature of biotite K-Ar system was within 1 million year. Combining the obtained paths of MMEs and host rocks with petrological information can provide insights into magma chamber processes. This suggests that MME flotation, migration, and spread through the magma chamber ceased at 1.5-0.5 Ma, indicating the emplacement age of the Kurobegawa granitic pluton, as no large-scale reheating episodes have occurred since then.
Chiba, Yusuke; Nishiyama, Yutaka; Tsubaki, Hirohiko; Iwai, Masaki; Furukawahara, Ryo; Ono, Hayato*; Hayasaka, Toshiro*
JAEA-Testing 2020-007, 42 Pages, 2021/02
Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development was the main part of the nuclear emergency response team of JAEA in full-scale operation starts on the 1st of April, 2020. In this section, we need to develop equipment for a JAEA nuclear emergency. To support full-scale operation, we have created a work robot for opening and closing doors, a work robot for opening and closing valves, and a reconnaissance robot for measuring radiation dose. This report describes how to operate a Reconnaissance robot.
Chiba, Yusuke; Nishiyama, Yutaka; Tsubaki, Hirohiko; Iwai, Masaki; Ono, Hayato*; Hayasaka, Toshiro*
JAEA-Testing 2020-006, 24 Pages, 2021/02
Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development was the main part of the nuclear emergency response team of JAEA in full-scale operation starts on the 1st of April, 2020. In this section, we need to develop equipment for a JAEA nuclear emergency. To support full- scale operation, we have created a work robot for opening and closing doors, a work robot for opening and closing valves, and a reconnaissance robot for measuring radiation dose. This report describes how to operate a work robot (opening and closing valves).
Chiba, Yusuke; Nishiyama, Yutaka; Tsubaki, Hirohiko; Iwai, Masaki; Furukawahara, Ryo; Ono, Hayato*; Hayasaka, Toshiro*
JAEA-Testing 2020-005, 29 Pages, 2021/02
Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development was the main part of the nuclear emergency response team of JAEA in full-scale operation starts on the 1st of April, 2020. In this section, we need to develop equipment for a JAEA nuclear emergency. To support full-scale operation, we have created a work robot for opening and closing doors, a work robot for opening and closing valves, and a reconnaissance robot for measuring radiation dose. This report describes how to operate the work robot (for opening and closing the door).
Nishiyama, Yutaka; Iwai, Masaki; Chiba, Yusuke; Tsubaki, Hirohiko; Ono, Hayato*; Hayasaka, Toshiro*; Hanyu, Toshinori*
JAEA-Technology 2020-007, 18 Pages, 2020/09
Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development is the main part of the nuclear emergency response team of Japan Atomic Energy Agency (JAEA) in full-scale operation starts on the 1st of April, 2020. The section needs to develop equipment for JAEA nuclear emergency. Because of dealing the full-scale operation, the section designed and produced two sets of Multi-joint Manipulator or (for Opening Doors) against Nuclear Disaster in order to put them on two crawler robots in 2018 fiscal year. And the section also designed and produced a Crawler Robot for Opening and Closing Manual Valves in 2019 fiscal year. This report shows two sets of Multi-Joint Manipulator (for Opening Doors) and a Crawler Robot for Opening and Closing Manual Valves designed and produced by Maintenance and Operation Section for Remote Control Equipment in 2018 and 2019 fiscal year.
Nishiyama, Yutaka; Iwai, Masaki; Tsubaki, Hirohiko; Chiba, Yusuke; Hayasaka, Toshiro*; Ono, Hayato*; Hanyu, Toshinori*
JAEA-Technology 2020-006, 26 Pages, 2020/08
Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development is the main part of the nuclear emergency response team of JAEA deal with Act on Special Measures Concerning Nuclear Emergency Preparedness. The section needs to remodel crawler-type robots for tasks, crawler-type scouting robots, and so on. About two crawler-type robots for tasks, the section designed and mounted advanced wireless communication equipment on manipulators mounted on the two robots. The crawler part of the robot has been able to be controlled by way of the new equipment, and when it is broken down, it can be changed by way of an original equipment. And the new equipment makes a single relay robot controllable both the crawler part and the manipulator part of the robot, in case of wireless relay robots being needed. And after checking the ability and characteristic about 5 wireless communication equipment, the section chose and mounted the best equipment on one crawler-type scouting robot. This report shows design and mounting advanced wireless communication equipment on the two crawler-type robots for tasks and on the one crawler-type scouting robot.
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.
Li, X.-P.*; Enokizono, Hayato*; Okamoto, Hiromi*; Yuri, Yosuke; Sessler, A. M.*; Wei, J.*
Physical Review Special Topics; Accelerators and Beams, 9(3), p.034201_1 - 034201_10, 2006/03
Times Cited Count:7 Percentile:47.32(Physics, Nuclear)It has been shown that the maintenance condition for a crystalline beam requires that there be no resonance between the crystal's phonon-frequencies, and the frequency associated with a beam moving through a lattice of periods. This resonance can be avoided provided that the phonon frequencies all are below half the lattice frequency. Here, we study in detail the phonon modes of several crystalline beams. The analytic results obtained in the smooth approximation are compared with numerical evaluations employing Fourier transform of the molecular dynamics (MD) modes. The stability of various crystalline structures is examined through systematic MD simulations based on several different lattice designs. The maintenance condition, when combined with either the simple analytic theory or the numerical evaluation of phonon modes, exhibits excellent agreement with the MD calculations of crystal stability. A confirmed maintenance condition, derived from linear-resonance criteria, is that the lattice frequency must not equal the sum of any two phonon frequencies.
Ishii, Tetsuro; Makii, Hiroyuki; Asai, Masato; Koura, Hiroyuki; Shigematsu, Soichiro*; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; et al.
no journal, ,
The ground-state bands of Th,U, Pu and Cm were established by measuring deexcitation rays. These nuclei were produced by the (O, O) and (O, Ne) two-nucleon transfer reactions with U, Pu and Cm targets. The rays in residual nuclei were identified by taking coincidence with scattering particles using high-resolution Si - detectors. By extending the systematics of the 2 energies into neutron-rich nuclei, we have found that the deformed shell gap disappears at Pu isotopes and that U and Pu isotopes have the possibility of the spherical shell closure at .
Ishii, Tetsuro; Makii, Hiroyuki; Asai, Masato; Shigematsu, Soichiro*; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Kaneko, Junichi*; Tome, Hayato; et al.
no journal, ,
no abstracts in English
Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Sato, Tetsuya; Ito, Yuta; Suzaki, Fumi; Nagame, Yuichiro*; et al.
no journal, ,
A specific phenomenon was found in fission-fragment mass distributions for nuclides around A=258 by spontaneous fission measurements. Fm256 splits into light and heavy fragments, like uranium isotopes, making two peaks in their mass distribution, whereas a sharp single peak was found in that of Fm258 which has only two more neutrons. In order to study such a specific phenomenon more widely, we performed an experiment of the multinucleon transfer fission in the O18+Es254 reaction at JAEA Tokai tandem accelerator facility.
Makii, Hiroyuki; Ishii, Tetsuro; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Kaneko, Junichi*; Tome, Hayato; Ichikawa, Shinichi; et al.
no journal, ,
We have measured in-beam rays in the neutron-rich Pu and Pu nuclei by means of Pu(O, O)Pu and Pu(O, O)Pu neutron transfer reactions, respectively. The ground-state band of Pu was established up to the state. The systematics of the 2 energies for the ground-state bands of Pu isotopes suggests that the deformed shell closure disappears in Pu. The measurement of deexcitation rays in Pu shows a small energy spacing between the neutron orbitals at , which explains the disappearance of the shell closure.
Ishii, Tetsuro; Makii, Hiroyuki; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Shizuma, Toshiyuki; Makishima, Akiyasu*; Tome, Hayato*; Shigematsu, Soichiro*; et al.
no journal, ,
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.
no journal, ,
no abstracts in English
Ishii, Tetsuro; Shigematsu, Soichiro; Makii, Hiroyuki; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; Kaneko, Junichi*; et al.
no journal, ,
no abstracts in English