Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2019, P. 132, 2020/08
Research and development were made for accuracy improvement of neutron capture cross section data on Am among minor actinides. First, the emission probabilities of decay rays were obtained with high accuracy, and the amount of the ground state of Am produced by reactor neutron irradiation of Am was examinded by -ray measurement. Next, the total amount of isomer and ground states was examoned by -ray measurement.
Nakamura, Shota*; Hyodo, Kazushi*; Matsumoto, Yuji*; Haga, Yoshinori; Sato, Hitoshi*; Ueda, Shigenori*; Mimura, Kojiro*; Saiki, Katsuyoshi*; Iso, Kosei*; Yamashita, Minoru*; et al.
Journal of the Physical Society of Japan, 89(2), p.024705_1 - 024705_5, 2020/02
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Hattori, Taisuke; Higa, Nonoka; Nakamine, Genki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Nakamura, Ai*; Shimizu, Yusei*; et al.
Journal of the Physical Society of Japan, 88(7), p.073701_1 - 073701_4, 2019/07
We report Te-NMR studies on a newly discovered heavy fermion superconductor UTe. Using a single crystal, we have measured the Te-NMR Knight shift and spin-lattice relaxation rate for fields along the three orthorhombic crystal axes. The data confirm a moderate Ising anisotropy for both the static () and dynamical susceptibilities () in the paramagnetic state above about 20 K. Around 20 K, however, we have observed a sudden loss of NMR spin-echo signal due to sudden enhancement of the NMR spin-spin relaxation rate , when the field is applied along the easy axis of magnetization (= axis). This behavior suggests the development of longitudinal magnetic fluctuations along the axis at very low frequencies below 20 K.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Kawakita, Yukinobu; Kikuchi, Tatsuya*; Inamura, Yasuhiro; Tahara, Shuta*; Maruyama, Kenji*; Hanashima, Takayasu*; Nakamura, Mitsutaka; Kiyanagi, Ryoji; Yamauchi, Yasuhiro*; Chiba, Kaori*; et al.
Physica B; Condensed Matter, 551, p.291 - 296, 2018/12
There are elemental liquid metals with complex structures far from the hard sphere (HS) packing model. Liquid Bi has an asymmetric first peak in the structure factors S(Q). The pair distribution function g(r) exhibits strange distance ratio of 1:2 between the first and the second peaks. Since a HS model with two kinds of radius produces asymmetry of the main peak in S(Q), existence of short-lived covalent bonds was discussed. Contrarily, modulation of the atomic distribution by the Friedel oscillations of shielding electrons around metallic ions was discussed. To examine its bonding nature from viewpoints of dynamic correlation functions, we have measured neutron quasielastic scattering of liquid Bi by using cold disk chopper spectrometer installed at MLF of J-PARC. The van Hove function revealed that the shoulder structure located at a longer side of the first peak in g(r) exhibits a longer relaxation time than the main structures such as the first and second peaks.
Nakamura, Shota*; Sakakibara, Toshiro*; Shimizu, Yusei*; Kittaka, Shunichiro*; Kono, Yohei*; Haga, Yoshinori; Pospisil, J.; Yamamoto, Etsuji
Progress in Nuclear Science and Technology (Internet), 5, p.123 - 127, 2018/11
Ikeda, Shugo*; Tsuchiya, Yu*; Zhang, X.-W.*; Kishimoto, Shunji*; Kikegawa, Takumi*; Yoda, Yoshitaka*; Nakamura, Hiroki; Machida, Masahiko; Glasbrenner, J.*; Kobayashi, Hisao*
Physical Review B, 98(10), p.100502_1 - 100502_6, 2018/09
The interplay between magnetism and superconductivity is one of important subjects to investigate the pairing mechanism in novel superconductors. We have found new coexistence between an antiferromagnetic order in the Fe sublattice and superconductivity of the FeAs-based EuFeAs superconductor in the pressure range from 2.4 to 3.0 GPa by Fe nuclear forward scattering (NFS) using a single crystal sample. The magnetic state in the Fe sublattice changes to a new antiferromagnetic one with superconductivity from a stripe-type antiferromagnetic one observed in normal conducting state at 2.7 GPa. Below the superconducting transition temperature, the temperature dependence of Fe NFS spectra reveals that the new antiferromagnetic order develops with the superconductivity. This non-trivial coupling of two ordered states in EuFeAs under pressure demonstrates a new and intriguing relationship between magnetism and superconductivity in Fe-based superconductors.
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Iwata, Takahiro*; Kitazato, Kohei*; Abe, Masanao*; Otake, Makiko*; Arai, Takehiko*; Arai, Tomoko*; Hirata, Naru*; Hiroi, Takahiro*; Honda, Chikatoshi*; Imae, Naoya*; et al.
Space Science Reviews, 208(1-4), p.317 - 337, 2017/07
NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 micrometer. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 micrometer-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K, which enables to retaining sufficient sensitivity and noise level in the 3 micrometer wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.
Takahashi, Naoki; Suzuki, Soju; Saito, Hiroto; Ueno, Takashi; Abe, Sadayoshi; Yamanaka, Atsushi; Tanigawa, Masafumi; Nakamura, Daishi; Sasaki, Shunichi; Mine, Tadaharu
Nippon Genshiryoku Gakkai Homu Peji (Internet), 20 Pages, 2017/05
no abstracts in English
Aikawa, Masayuki*; Iwamoto, Osamu; Ebata, Shuichiro*; Kunieda, Satoshi; Nakamura, Shoji; Koura, Hiroyuki
JAEA-Conf 2015-003, 332 Pages, 2016/03
The 2014 Symposium on Nuclear Data was held at Conference Hall, Hokkaido University, on November 27 and 28, 2014. The symposium was organized by the Nuclear Data Division of the Atomic Energy Society of Japan, Hokkaido Branch of the Atomic Energy Society of Japan, and Nuclear Reaction Data Centre, Faculty of Science, Hokkaido University in cooperation with Nuclear Science and Engineering Directorate of Japan Atomic Energy Agency. In the symposium, there were two tutorials, "Cross section measurement strategy for long lived fission product" and "Physics and Nuclear Data in Radiation Therapy" and four sessions, "A Neutron TOF Measurement Instrument desired by Nuclear Data Community", "Recent Topics", "Application of Nuclear Data", and "Nuclear Theory and Nuclear Data". In addition, recent research progress on experiments, evaluation, benchmark and application was presented in a poster session. Among 88 participants, all presentations and following discussions were very active and fruitful. This report consists of total 62 papers including 2 tutorials, 16 oral and 44 poster presentations.
Fujinami, Shun*; Takeda, Kiyoko*; Onodera, Takefumi*; Sato, Katsuya; Shimizu, Tetsu*; Wakabayashi, Yu*; Narumi, Issey*; Nakamura, Akira*; Ito, Masahiro*
Genome Announcements (Internet), 3(5), p.e01005-15_1 - e01005-15_2, 2015/09
Adachi, Taihei*; Ikedo, Yutaka*; Nishiyama, Kusuo*; Yabuuchi, Atsushi*; Nagatomo, Takashi*; Strasser, P.*; Ito, Takashi; Higemoto, Wataru; Kojima, Kenji*; Makimura, Shunsuke*; et al.
JPS Conference Proceedings (Internet), 8, p.036017_1 - 036017_4, 2015/09
Nakamura, Toshihiro*; Adachi, Sadao*; Fujii, Minoru*; Sugimoto, Hiroshi*; Miura, Kenta*; Yamamoto, Shunya
Physical Review B, 91(16), p.165424_1 - 165424_8, 2015/04
Semiconductor nanocrystals have unique electrical and optical properties, because of the quantum confinement effect, and the doping of impurities into nanocrystals. In this study, we investigated the photoluminescence (PL) properties of phosphorus- (P) and boron- (B) co-doped Si nanocrystals (Si NCs), which was synthesized using an ion implantation technique. The Si-NC size (average diameter: 3.5, 4.4, 5.2 nm) and the P and B ion doses (0.1-4.510 cm)values were systematically varied. We find that the PL peak energy shifts to lower values with increasing the average diameters of Si NCs and PB ion dose. The results of PL measurements indicate that the PL spectra are due to the band-to-band transition at the reduced Si-NC band gap caused by the formation of impurity and the radiative transitions between defect- and/or impurity-related localized states. It was found that the PL properties can be controlled by varying the Si-NC size as well as the dopant concentration.
Higuchi, Kyoko*; Kanai, Masatake*; Tsuchiya, Masahisa*; Ishii, Haruka*; Shibuya, Naofumi*; Fujita, Naoko*; Nakamura, Yasunori*; Suzui, Nobuo; Fujimaki, Shu; Miwa, Eitaro*
Frontiers in Plant Science (Internet), 6, p.138_1 - 138_6, 2015/03
Sukegawa, Atsuhiko; Iida, Hiromasa*; Itoga, Toshio*; Okumura, Keisuke; Kai, Tetsuya; Konno, Chikara; Nakashima, Hiroshi; Nakamura, Takashi*; Ban, Shuichi*; Yashima, Hiroshi*; et al.
Hoshasen Shahei Handobukku; Kisohen, p.299 - 356, 2015/03
no abstracts in English
Nakamura, Shinichi*; Kondo, Hikari*; Suzui, Nobuo; Yin, Y.-G.; Ishii, Satomi; Kawachi, Naoki; Rai, Hiroki*; Hattori, Hiroyuki*; Fujimaki, Shu
Molecular Physiology and Ecophysiology of Sulfur, p.253 - 259, 2015/00
Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi*; Iwase, Hiroshi*; Toyoda, Akihiro*; Yashima, Hiroshi*; Sekimoto, Shun*; Oishi, Koji*; Sakamoto, Yukio*; Nakashima, Hiroshi; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.337 - 340, 2014/04
The Neutrinos at the Main Injector (NuMI) at Fermilab produces intense neutrino beam to investigate the phenomena of the neutrino mixing and oscillation. The Hadron Absorber, consists of thick blocks of aluminum, iron and concrete, is placed at the end of decay volume as a dump for primary proton and secondary particles generated in NuMI. In order to estimate the shielding effect, the reaction rate measurements with activation detector were carried out on the back surface of the absorber. The induced activities in the detectors were measured by analyzing their -ray spectra using HPGe detectors. Two kind of peak was showed on two-dimensional distributions of obtained reaction rates at right angle to the beam direction. One was strong peaks at the both horizontal side. And, another smaller was at the top. It was concluded that these peaks were the results of particles streaming through the gaps in the Hadron Absorber shielding.
Takasaki, Koji; Yasumune, Takashi; Onishi, Takashi; Nakamura, Keisuke; Ishimi, Akihiro; Ito, Chikara; Osaka, Masahiko; Ono, Masashi*; Hatakeyama, Shuichi*; Takahashi, Hiroyuki*; et al.
JAEA-Research 2013-043, 33 Pages, 2014/01
In the Fukushima Daiichi Nuclear Power Plant, it is assumed that the core fuels melted partially or wholly, and the normal technique of accounting for a fuel assembly is not applicable. Therefore, it is necessary to develop the transparent and rational technique of accounting in the process of collection and storage of fuel debris. In this research, an application of the superconducting phase Transition Edge Sensor microcalorimeter (TES microcalorimeter) is studied for the accounting of nuclear materials in the fuel debris. It is expected that the detailed information of nuclear materials and fission products in fuel debris is obtained by using a high-resolution characteristic of TES microcalorimeter. In this report, the principle of TES microcalorimeter, the measurement experiment using TES in JAEA, and the simulated calculation using the EGS5 code system are summarized.