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Ca cast doubt on a doubly magic 
CaChen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
Times Cited Count：1 Percentile：0.02(Astronomy & Astrophysics)Gamma decays were observed in 
Ca and 
Ca following quasi-free one-proton knockout reactions from 
Sc. For Ca, a 
ray transition was measured to be 1456(12) keV, while for Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 
decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 
level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 
and 
orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic Ca and potentially drives the dripline of Ca isotopes to 
Ca or even beyond.
-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：2 Percentile：31.9(Chemistry, Analytical)no abstracts in English
Yoshimune, Wataru*; Kikkawa, Nobuaki*; Yoneyama, Hiroaki*; Takahashi, Naoko*; Minami, Saori*; Akimoto, Yusuke*; Mitsuoka, Takuya*; Kawaura, Hiroyuki*; Harada, Masashi*; Yamada, Norifumi*; et al.
ACS Applied Materials & Interfaces, 14(48), p.53744 - 53754, 2022/11
Times Cited Count：6 Percentile：59.75(Nanoscience & Nanotechnology)
CsUchiyama, Yusuke*; Tokunaga, Natsuki*; Azuma, Kohei*; Kamidaira, Yuki; Tsumune, Daisuke*; Iwasaki, Toshiki*; Yamada, Masatoshi*; Tateda, Yutaka*; Ishimaru, Takashi*; Ito, Yukari*; et al.
Science of the Total Environment, 816, p.151573_1 - 151573_13, 2022/04
Times Cited Count：7 Percentile：68.71(Environmental Sciences)no abstracts in English
Yoshida, Shogo*; Koyama, Takehide*; Yamada, Haruhiko*; Nakai, Yusuke*; Ueda, Koichi*; Mito, Takeshi*; Kitagawa, Kentaro*; Haga, Yoshinori
Physical Review B, 103(15), p.155153_1 - 155153_5, 2021/04
Times Cited Count：1 Percentile：0(Materials Science, Multidisciplinary)Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：43 Percentile：96.93(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Kamiya, Junichiro; Okabe, Kota; Kinsho, Michikazu; Moriya, Katsuhiro; Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Wada, K.*
Journal of Physics; Conference Series, 1350, p.012149_1 - 012149_6, 2019/12
Times Cited Count：3 Percentile：82.33(Physics, Particles & Fields)To obtain a getter effect to titanium vacuum duct surface, the method to remove the oxide on the surface by sputtering with ionized molecules has been developed. In the method, a sheet-shaped gas distribution with a uniform and high density is generated through a narrow slit by a small amount of gas. In this report, the gas density distribution was calculated by the Monte Carlo simulation code. As a result, it was found that a gas injection from both directions was effective to generate uniform density distribution. Furthermore, the gas injection method was applied to a non-destructive beam profile monitor, that detects ions generated by the interaction between gas molecules and beam. In this monitor, dependence of the beam profile on the injected gas amount was measured. A small amount of injected gas was found to be ideal for the beam profile measurements in the unsaturated and a high S/N ratio region.
Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu
Vacuum and Surface Science, 62(7), p.400 - 405, 2019/07
no abstracts in English
Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu
Proceedings of 10th International Particle Accelerator Conference (IPAC '19) (Internet), p.2567 - 2570, 2019/06
no abstracts in English
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
Times Cited Count：259 Percentile：99.73(Multidisciplinary Sciences)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.
Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.88 - 92, 2018/08
no abstracts in English
Ishikuro, Yasuhiro; Nemoto, Tsutomu; Yamada, Yusuke; Oyama, Koji
Nihon Hozen Gakkai Dai-15-Kai Gakujutsu Koenkai Yoshishu, p.501 - 505, 2018/07
After operating until December 2010, JRR-4 was under periodical self-inspection for the next operation. After that, it suffered from the Great East Japan Earthquake on March 11, 2011. But it recovered almost a year later. However, we determined to decommission JRR-4 in September 2013. After that, we received the approval of the decommissioning plan of JRR-4 on June 7, 2017. And we received the approval of the change of the safety regulations related to it. Subsequently JRR-4 was shifted to decommission phase in December 2017. This report describes the outline of the decommissioning plan of JRR-4 and the implementation status.
Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Komatsu, Kazuki*; Yamada, Akihiro*; Inamura, Yasuhiro; Nakatani, Takeshi; Seto, Yusuke*; Nagai, Takaya*; Utsumi, Wataru; et al.
Nuclear Instruments and Methods in Physics Research A, 780, p.55 - 67, 2015/04
Times Cited Count：75 Percentile：99.01(Instruments & Instrumentation)PLANET is a time-of-flight (ToF) neutron beamline dedicated to high-pressure and high-temperature experiments. The large six-axis multi-anvil high-pressure press designed for ToF neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators to eliminate parasitic scattering from the high-pressure cell assembly. The high performance of the diffractometer for the resolution (
/ 
0.6%) and the accessible -spacing range (0.2-8.4 
) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.
Sawada, Yusuke*; Uozumi, Yusuke*; Nogamine, Sho*; Yamada, Takehiro*; Iwamoto, Yosuke; Sato, Tatsuhiko; Niita, Koji*
Nuclear Instruments and Methods in Physics Research B, 291, p.38 - 44, 2012/11
Times Cited Count：17 Percentile：76.97(Instruments & Instrumentation)The Intranuclear cascade with emission of light fragment (INC-ELF) code has been developed and implemented in the particle and heavy ion transport code system (PHITS). The INC-ELF code explicitly includes nucleon correlations within the framework of the INC model to describe light fragment emissions from nuclear spallation reactions. In addition to the degrees of freedom of nucleons, the developed code also accounts for pions, 
and 
, and it can cover the energy range up to 3 GeV. The predictive capabilities of the ELF/PHITS system have been verified through comparison with a diverse set of experimental observations. As a result, our ELF/PHITS code has demonstrated strong predictive capability for all of these data, although areas requiring future study remain due to the lack of experimental data on high-energy cluster production.
and CeIrSi with the non-centrosymmetric crystal structureOkuda, Yusuke*; Miyauchi, Yuichiro*; Ida, Yuki*; Takeda, Yuji*; Tonohiro, Chie*; Ozuchi, Yasuhiro*; Yamada, Tsutomu*; Nguyen, D.; Matsuda, Tatsuma; Haga, Yoshinori; et al.
Journal of the Physical Society of Japan, 76(4), p.044708_1 - 044708_11, 2007/04
Times Cited Count：87 Percentile：91.8(Physics, Multidisciplinary)Single crystals of LaIrSi and CeIrSi were grown by the Czochralski pulling method in a tetra-arc furnace and the magnetic and superconducting properties, together with super- conductivity in CeIr
Co
Si, were clarified by measuring the electrical resistivity, specific heat, magnetic susceptibility, magnetization and de Haas-van Alphen (dHvA) effect. From the results of the dHvA experiment for LaIrSi, the Fermi surface is found to split into two Fermi surfaces due to the spin-orbit interaction arising from the non-centrosymmetric crystal structure. The electronic state of CeIrSi is tuned from the antiferro- magnetic state to the superconducting state by applying pressure. The upper critical field H
(0) at a pressure of 2.65 GPa is found to be highly anisotropic. Large magnitude and anisotropy of H(0) in CeIrSi are consistent with the theoretical prediction for superconductivity in the non-centrosymmetric crystal structure.
PdSi
Nguyen, D.; Haga, Yoshinori; Matsuda, Tatsuma; Yamada, Tsutomu*; Thamizhavel, A.*; Okuda, Yusuke*; Takeuchi, Tetsuya*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; et al.
Journal of the Physical Society of Japan, 76(2), p.024702_1 - 024702_6, 2007/02
Times Cited Count：5 Percentile：37.28(Physics, Multidisciplinary)We succeeded in growing a single crystal of CePdSi with the orthorhombic crystal structure by the Sn-flux method and measured the electrical resistivity, specific heat, magnetic susceptibility and magnetization. The antiferromagnetic ordering was confirmed to be 
= 7.2 K. The electronic specific heat coefficient was determined as 77 mJ/K
mol
Ce. The antiferromagnetic easy-axis was found to be the [001] direction, with an ordered moment of 
= 1.3 
/Ce, while [100] and [010] directions are hard-axes in magnetization. We observed a metamagnetic transition at 5.7 T for 
[001] and a saturation of magnetization above 12.1 T. The characteristic magnetic phase diagram was constructed. The crystalline electric field (CEF) scheme was proposed for CePdSi, where the splitting energies between the ground state and two excited doublets in the CEF scheme are estimated to be 87 K and 504 K, respectively.
without inversion symmetrySugitani, Ichiro*; Okuda, Yusuke*; Shishido, Hiroaki*; Yamada, Tsutomu*; Thamizhavel, A.*; Yamamoto, Etsuji; Matsuda, Tatsuma; Haga, Yoshinori; Takeuchi, Tetsuya*; Settai, Rikio*; et al.
Journal of the Physical Society of Japan, 75(4), p.043703_1 - 043703_4, 2006/04
Times Cited Count：338 Percentile：98.83(Physics, Multidisciplinary)We report the discovery of pressure-induced superconductivity in an antiferromagnet CeIrSi, which lacks inversion symmetry in the tetragonal crystal structure. The Neel temperature 
= 5.0 K at ambient pressure decreases monotonically with increasing pressure, and becomes zero at about 2.5 GPa. Superconductivity appears in a wide pressure region from 1.8 GPa to about 3.5 GPa, with a relatively large superconduting transition temperature Tsc= 1.6 K and a large upper critical field 
(0) = 11.1 T at 2.5 GPa, indicating heavy-fermion superconductivity.
Sr
MnO
(x0.12)Inami, Toshiya; Ikeda, Naoshi*; Murakami, Yoichi*; Koyama, Ichiro*; Wakabayashi, Yusuke*; Yamada, Yasusada*
Japanese Journal of Applied Physics, 38(suppl.38-1), p.212 - 214, 1999/06
Times Cited Count：15 Percentile：65.98(Physics, Applied)no abstracts in English
Kuno, Yusuke; Yamada, Keiji;
Analytical Sciences, 6, p.97 - 101, 1990/00
Times Cited Count：2 Percentile：15.62(Chemistry, Analytical)