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Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.
Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03
Times Cited Count:4 Percentile:57.13(Physics, Nuclear)Steppenbeck, D.*; Takeuchi, Satoshi*; Aoi, Nori*; Doornenbal, P.*; Matsushita, Masafumi*; Wang, H.*; Baba, Hidetada*; Go, Shintaro*; Holt, J. D.*; Lee, J.*; et al.
Physical Review C, 96(6), p.064310_1 - 064310_10, 2017/12
Times Cited Count:18 Percentile:80.82(Physics, Nuclear)no abstracts in English
Steppenbeck, D.*; Takeuchi, Satoshi*; Aoi, Nori*; Doornenbal, P.*; Matsushita, Masafumi*; Wang, H.*; Utsuno, Yutaka; Baba, Hidetada*; Go, Shintaro*; Lee, J.*; et al.
Physical Review Letters, 114(25), p.252501_1 - 252501_6, 2015/06
Times Cited Count:44 Percentile:87.83(Physics, Multidisciplinary)The neutron-rich nucleus Ar is produced by the fragmentation reactions of Ca, Sc, and Ti at the RIBF facility in RIKEN, and its deexcited rays are observed for the first time. The first level in Ar is identified to lie at 1178(18)keV from the most intense -ray spectra. This experimental data, together with the systematics of the levels for surrounding nuclei, is analyzed with large-scale shell-model calculations. Consequently, the sub-shell gap in Ar is equivalent to that of Ca, thus making the level in Ar higher than that of Ar. The shell-model calculation also predicts that the sub-shell gap enhances in going from Ca to Ar, which will be verified by forthcoming experiments for Ar.
Honda, Tomohiro*; Minoshima, Yusuke*; Yokoi, Yuki*; Takayanagi, Toshiyuki*; Shiga, Motoyuki
Chemical Physics Letters, 625, p.174 - 178, 2015/04
Times Cited Count:5 Percentile:19.29(Chemistry, Physical)Electron attachment dynamics to the guanine-cytosine (G-C) base pair in the gas phase isstudied using DFT and molecular dynamics. The potential energy surface of the G-C anion isconstructed with the empirical-valence-bond method using force-field information obtained from long-range corrected DFT calculations. Ring-polymer molecular dynamics simulations predict that theinitial dipole-bound anion readily converts into the valence-bound anion within 0.1 ps and proton-transfer occurs subsequently within 10 ps. The same process was found in classical simulations, buton a much slower time scale. This result suggests that nuclear quantum effects are important inunderstanding DNA damage by low-energy electrons.
Kobayashi, Nobuyuki*; Nakamura, Takashi*; Kondo, Yosuke*; Tostevin, J. A.*; Utsuno, Yutaka; Aoi, Nori*; Baba, Hidetada*; Barthelemy, R.*; Famiano, M. A.*; Fukuda, Naoki*; et al.
Physical Review Letters, 112(24), p.242501_1 - 242501_5, 2014/06
Times Cited Count:89 Percentile:94.33(Physics, Multidisciplinary)no abstracts in English
Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Tostevin, J. A.*; Utsuno, Yutaka; Aoi, Nori*; Baba, Hidetada*; Fukuda, Naoki*; Gibelin, J.*; et al.
Physical Review Letters, 112(14), p.142501_1 - 142501_5, 2014/04
Times Cited Count:62 Percentile:91.13(Physics, Multidisciplinary)no abstracts in English
Steppenbeck, D.*; Takeuchi, Satoshi*; Aoi, Nori*; Doornenbal, P.*; Matsushita, Masafumi*; Wang, H.*; Baba, Hidetada*; Fukuda, Naoki*; Go, Shintaro*; Homma, Michio*; et al.
Nature, 502(7470), p.207 - 210, 2013/10
Times Cited Count:285 Percentile:99.78(Multidisciplinary Sciences)no abstracts in English
Ideguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.
Progress of Theoretical Physics Supplement, (196), p.427 - 432, 2012/10
Tanaka, Momoko; Nakazato, Tomoharu*; Shimizu, Toshihiko*; Yamanoi, Kohei*; Sakai, Kohei*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Oba, Toshiyuki; Kaihori, Takeshi; Ochi, Yoshihiro; et al.
JAEA-Conf 2011-001, p.126 - 128, 2011/03
The spatial resolution of hydrothermal method grown zinc oxide (ZnO) scintillator was evaluated using X-ray laser focused with Fresnel zone plate. The fluorescence image of the ZnO scintillator was measured to be less than 10um using CCD camera coupled with a Schbartzchild expander mirror. The availability of large size ZnO crystal up to 3-inch is quite attractive for future lithography and imaging applications.
Ideguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.
Physics Letters B, 686(1), p.18 - 22, 2010/03
Times Cited Count:36 Percentile:86.72(Astronomy & Astrophysics)A rotational band with five -ray transitions ranging from 2 to 12 states was identified in Ar. The deduced transition quadrupole moment of 1.45 0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartee Fock Bogoliubov calculations and a multiparticle-multihole configuration is assigned to the band.
Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Aoi, Nori*; Baba, Hidetada*; Deguchi, Shigeki*; Fukuda, Naoki*; Gibelin, J.*; Inabe, Naoto*; et al.
Physical Review Letters, 103(26), p.262501_1 - 262501_4, 2009/12
Times Cited Count:198 Percentile:97.53(Physics, Multidisciplinary)no abstracts in English
Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Nishiuchi, Mamiko; Ogura, Koichi; Orimo, Satoshi; Ma, J.*; Sagisaka, Akito; Kanazawa, Shuhei; Kondo, Shuji; et al.
IEEE Transactions on Plasma Science, 36(4), p.1872 - 1877, 2008/08
Times Cited Count:7 Percentile:28.47(Physics, Fluids & Plasmas)A dependence of cut-off proton kinetic energy on laser prepulse duration has been observed. ASE pedestal duration is controlled by a fast electro-optic pulse slicer where the risetime is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this risetime using a stretched, frequency chirped pulse.
Shizuma, Toshiyuki; Ishii, Tetsuro; Makii, Hiroyuki*; Hayakawa, Takehito; Matsuda, Makoto; Shigematsu, Soichiro*; Ideguchi, Eiji*; Zheng, Y.*; Liu, M.*; Morikawa, Tsuneyasu*; et al.
Physical Review C, 77(4), p.047303_1 - 047303_4, 2008/04
Times Cited Count:10 Percentile:56.12(Physics, Nuclear)Modest spin states in neutron-rich W have been populated using a W(O,O) one-neutron transfer reaction. While negative-parity bands previously known are extended to higher spin, two positive-parity bands are newly identified. Configurations based on i orbitals are assigned to these bands from an analysis of the level energy systematics as well as the g-factors derived from in-band branching ratios.
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.
Nuclear Fusion, 47(10), p.S668 - S676, 2007/10
Times Cited Count:34 Percentile:73.71(Physics, Fluids & Plasmas)The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 510 m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.
Orimo, Satoshi; Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Li, Z.*; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.
Japanese Journal of Applied Physics, Part 1, 46(9A), p.5853 - 5858, 2007/09
Times Cited Count:17 Percentile:54.99(Physics, Applied)A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Titanium Sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of 10m, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.
Yogo, Akifumi; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Sagisaka, Akito; Pirozhkov, A. S.; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.
Physics of Plasmas, 14(4), p.043104_1 - 043104_6, 2007/04
Times Cited Count:63 Percentile:88.17(Physics, Fluids & Plasmas)Fast protons are observed by a newly-developed time-of-flight spectrometer, which provides proton-energy distributions immediately after the irradiation of a laser pulse having an intensity of W/cm onto a 5-m-thick copper foil. The maximum proton energy is found to increase when the intensity of a fs-prepulse arriving 9 ns before the main pulse increases from 10 to 10 W/cm. Interferometric measurement indicates that the preformed-plasma expansion at the front surface is smaller than 15 m, which corresponds to the spatial resolution of the diagnostics. This sharp gradient of the plasma makes a beneficial effect on increasing the absorption efficiency of the main-pulse energy, resulting in the increase in the proton energy. This is supported by the result that the X-ray intensity from the laser plasma clearly increases with the prepulse intensity.
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Muto, Takashi*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03
The performance of net-current free Heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fueling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an Internal Diffusion Barrier (IDB) by combination of efficient pumping of the local island divertor function and core fueling by pellet injection has realized a super dense core as high as 510m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5 % and a discharge duration of 54-min. with a total input energy of 1.6 GJ (490 kW in average) are also highlighted. The progress of LHD experiments in these two years is overviewed with highlighting IDB, high and long pulse.
Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Mori, Michiaki; Ma, J.-L.; Pirozhkov, A. S.; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.
Proceedings of 7th Pacific Rim Conference on Lasers and Electro-Optics (CLEO-PR 2007) (CD-ROM), p.77 - 79, 2007/00
We are developing a proton accelerator using an intense lasers with a focused intensity of 10 W/cm. To monitor proton energy spectra as well as plasma parameters at each laser shot, we are using real time detectors. The proton energy of MeV is stably obtained for applications.
Shizuma, Toshiyuki; Ishii, Tetsuro; Makii, Hiroyuki; Hayakawa, Takehito; Shigematsu, Soichiro; Matsuda, Makoto; Ideguchi, Eiji*; Zheng, Y.*; Liu, M.*; Morikawa, Tsuneyasu*; et al.
European Physical Journal A, 30(2), p.391 - 396, 2006/11
Times Cited Count:12 Percentile:61.41(Physics, Nuclear)Excited states in neutron-rich W have been populated using a W(O,O) reaction. In-beam rays were measured in coincidence with scattered particles detected by a high-resolution - Si telescope. In this experiment, the ground state band has been identified up to . The band, the octupole band, and a 2-quasiparticle state were also observed. The results are compared with predictions of self-consistent HFB cranking calculations and blocked-BCS multi-quasiparticle calculations.
Naoe, Takashi; Futakawa, Masatoshi; Oi, Toshiyuki; Wakui, Takashi; Motohashi, Yoshinobu*
Zairyo, 55(10), p.944 - 950, 2006/10
Mercury target will be installed at the material and life facility in J-PARC. Pressure waves will be generated in mercury by thermally shocked heat deposition when the high intense proton beams bombard the mercury target. Cavitation will be induced through the pressure wave propagation in the mercury and eroded the vessel inner surface contacting with the mercury. The eroded vessel wall is damaged by cyclic fatigue because pulsed proton beams strike the target repeatedly. It is, therefore, important to investigate the fatigue strength of the eroded vessel wall. In order to precisely investigate the effects of damages, at the first, the pitting damage by erosion was evaluated against the number of pulses, and then the fatigue test was carried out using the specimen with a certain pitting damage. As a result, the fitigue limit with pitting damage is degraded to less than half of that without pitting damage, after 2500 hrs operation at 1MW.