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Iwamoto, Osamu; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Nakayama, Shinsuke; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Nagaya, Yasunobu; Tada, Kenichi; et al.
EPJ Web of Conferences, 284, p.14001_1 - 14001_7, 2023/05
Times Cited Count:2 Percentile:83.48(Nuclear Science & Technology)
-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:8.68(Physics, Applied)Kwon, Saerom*; Konno, Chikara; Ota, Masayuki*; Kasugai, Atsushi*
Journal of Nuclear Science and Technology, 57(3), p.344 - 351, 2020/03
Times Cited Count:2 Percentile:16.32(Nuclear Science & Technology)We found out that there was a questionable iron DPA value just above 20 MeV neutron energy in neutronics analyses of A-FNS using FENDL-3.1d. Our detailed investigation on the iron data in FENDL-3.1d figured out that residual nucleus production yield data of
Fe just above 20 MeV had a problem, which caused a sharp spike just above 20 MeV in the DPA cross section of
Fe. Thus we modified the yield data of
Fe and verified that the questionable DPA value disappeared using the modified data. We also examined DPA cross sections of other nuclei in FENDL-3.1d. It was found out that DPA cross sections of more than 70% of nuclei in FENDL-3.1d have similar problems as that of
Fe.
Kwon, Saerom*; Konno, Chikara; Ota, Masayuki*; Ochiai, Kentaro*; Sato, Satoshi*; Kasugai, Atsushi*
Fusion Engineering and Design, 144, p.209 - 214, 2019/07
Times Cited Count:4 Percentile:31.79(Nuclear Science & Technology)We performed a TENDL-2017 benchmark test with iron shielding experiments by using 40 and 65 MeV neutrons, in order to verify a nuclear data library above 20 MeV for neutronics analyses of A-FNS. We found out that the calculated neutron spectra with TENDL-2017 unnaturally increased near 30 MeV. We figured out that incorrect secondary neutron spectrum data in
Fe,
Fe and
Fe at 30 MeV caused the increase of the neutron flux. Similar problems occurred in a lot of nuclei of TENDL-2017, TENDL-2015 and FENDL-3.1d from TENDL-2010 and TENDL-2011.
collisions at
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07
Times Cited Count:34 Percentile:75.46(Astronomy & Astrophysics)We report on the event structure and double helicity asymmetry (
) of jet production in longitudinally polarized
collisions at
= 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured
= -0.0014
0.0037 at the lowest
bin and -0.0181
0.0282 at the highest
bin. The measured
is compared with the predictions that assume various
distributions.
collisions at
= 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:194 Percentile:99.38(Physics, Nuclear)Transverse momentum distributions and yields for
, and
in
collisions at
= 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different
collisions. We also present the scaling properties such as
and
scaling and discuss the mechanism of the particle production in
collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
and Au+Au collisions at
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:9 Percentile:51.11(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled
collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to
collisions.
+
collisions at
= 200 GeV and scaling properties of hadron productionAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03
Times Cited Count:185 Percentile:98.32(Astronomy & Astrophysics)The PHENIX experiment at RHIC has measured the invariant differential cross section for production of
,
,
and
mesons in
collisions at
= 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters,
and
, determining the high
and characterizing the low
regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Ishii, Akito*; Iwase, Akihiro*; Yokoyama, Yoshihiko*; Konno, Toyohiko*; Kawasuso, Atsuo; Yabuuchi, Atsushi; Maekawa, Masaki; Hori, Fuminobu*
Journal of Physics; Conference Series, 225, p.012020_1 - 012020_6, 2010/06
Times Cited Count:5 Percentile:84.21(Physics, Applied)To reveal the relationship between mechanical properties and microscopic structure of Zr-based amorphous metals, we performed positron annihilation measurements on specimens with different Zr contents. Although the positron lifetimes were nearly the same for all the specimens, the Doppler broadening of annihilation radiation spectra were significantly different for the specimens at and above the eutectic point. This indicates that both the structure and composition of free volumes depend on the Zr-content.
Okada, Koichi*; Kondo, Keitaro; Ochiai, Kentaro; Sato, Satoshi; Konno, Chikara; Okamoto, Atsushi*; Kobuchi, Takashi*; Kitajima, Sumio*; Sasao, Mamiko*
Journal of Plasma and Fusion Research SERIES, Vol.8, p.666 - 669, 2009/09
Measurement of fuel ion density ratio, 
/
, is required for burning control on ITER. The measured 
/
ratio must be fed back in real time. A neutron measurement system to measure 
/
should be operable at high counting rate. It is estimated that the number of emitted DT neutrons is 200 times higher than that of DD neutrons under the condition of ITER standard operation. A neutron measurement system was developed using a DT/DD generator, where DT neutrons are dominant and DD neutrons are contaminated slightly in the neutron beam. The measurement instrument was a TOF spectrometer. Signals originating from each neutron must be distinguished in order to measure the fuel ratio. We developed a circuit system with discrimination windows to distinguish each signal pulse, and DT and DD neutrons were measured separately and simultaneously with this system. The experimental result indicates a possibility that this system is suitable for measurement of fuel ion density ratio on ITER.
2 surfaceYamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito; Suemitsu, Maki*
Applied Surface Science, 254(19), p.6232 - 6234, 2008/07
Times Cited Count:4 Percentile:20.56(Chemistry, Physical)The room temperature adsorbed state of oxygen molecules on Si(110)-16
2 surface and the structural change after a mild annealing has been investigated by synchrotron radiation photoemission spectroscopy. As a result, despite the very small dosage of oxygen, Si
and Si
components already appear in addition to Si
. This is likely to be caused by a selective adsorption of O
molecules into the vicinity of already oxidized sites. After annealing, we found that binding energy of Si
and Si
increase and approach to their corresponding peak positions of a thermally-grown oxide, and this increase indicates relaxation of the Si-O bond length and Si-O-Si bond angle of metastable oxygen atoms.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Kato, Atsushi*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
Shingaku Giho, 108(80), p.65 - 70, 2008/06
The growth process of thermal oxides on Si(110) surface and the development of their interfacial bonding structures have been investigated by using real-time synchrotron radiation photoemission spectroscopy. As a result, it was clarified that the Si
component in the Si 2p core-level spectra is always much higher than that of Si
for 0-1 mono-layer (ML) oxides on Si(110) surface. Observations on the time-evolution of the O 1s core-level spectrum indicates that the autocatalytic-reaction model proposed for the Si(001) oxidation can be also applicable to the Si(110) oxidation.
2 surface by scanning tunneling microscopyTogashi, Hideaki*; Takahashi, Yuya*; Kato, Atsushi*; Konno, Atsushi*; Asaoka, Hidehito; Suemitsu, Maki*
Japanese Journal of Applied Physics, Part 1, 46(5B), p.3239 - 3243, 2007/05
Times Cited Count:13 Percentile:45.62(Physics, Applied)On Si(110) surface, the hole mobility is enhanced as compared with that on Si(001) surface. This surface is also to be used in the next-generation three-dimensional devices. We conducted scanning-tunneling-microscopy (STM) observation on the initial oxidation of Si(110)-16
2 surface. The present result suggests less occurrence of etching under the oxidation condition. There is a possibility to form an abrupt oxide/Si interface on the Si(110) surface.
2 surfaces by O 1s photoemission spectroscopy using synchrotron radiationSuemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*; Enta, Yoshiharu*
Japanese Journal of Applied Physics, Part 1, 46(4B), p.1888 - 1890, 2007/04
Times Cited Count:12 Percentile:43.16(Physics, Applied)Initial oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy. The time evolution of the O 1s spectrum shows occurrence of rapid oxidation just after the introduction of the oxygen molecules, which is evidenced by the considerable peak intensity corresponding to oxygen exposure of as low as 1.5L (1L=1.33
10
Pa s). This initial oxide is dominated by a state with a relatively low binding energy, which is gradually replaced by a state with a relatively high binding energy with the increase of the oxygen exposure, resulting in the low-KE shift of the O 1s peak. Comparison with previously reported O 1s spectra from dry-oxidized Si(111) surface suggests oxidation at or around the adatoms of Si(110)-16
2 clean surface as a likely oxidation state for this low-binding-energy peak.
2Suemitsu, Maki*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito
Materials Research Society Symposium Proceedings, Vol.996, p.19 - 25, 2007/00
From its high hole mobility, as well as its inevitable usage as an active layer in multi-gated FETs, Si(110) surface is expected to play a crucial role in the next generation CMOS devices. We have investigated the initial oxidation of Si(110) surface by using SR-XPS and STM. Reflecting its atomistic structure of the 16
2 reconstruction, initial oxidation of Si(110) surface shows a unique behavior which is not observed on other surfaces like (111) and (001).
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
Shingaku Giho, 106(108), p.61 - 63, 2006/06
no abstracts in English
2 surface by photoemission spectroscopySuemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Enta, Yoshiharu*; Narita, Yuzuru*
ECS Transactions, 3(2), p.311 - 316, 2006/00
Initial thermal oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy with synchrotron radiation. The Si(110) initial oxidation is characterized by presence of a rapid oxidation just after the introduction of gaseous oxygen molecules. Peak separation of the O1s photoemission spectra suggests the presence of at least two distinct oxidation sites on the surface, which may reflect the complicated surface structure of the Si(110)-16
2 reconstruction.
2 surface using SR-PES and STMYamamoto, Yoshihisa*; Togashi, Hideaki*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Kato, Atsushi*; Hasegawa, Satoshi*; Konno, Atsushi*; Suemitsu, Maki*; Yoshigoe, Akitaka; et al.
no journal, ,
We have investigated that initial oxidation processes of Si(110) surfaces at room temperature and thermal stability of the oxide layer via synchrotron radiation photoemission spectroscopy (SR-PES) and scanning tunneling microscopy (STM). We found in the SR-PES experiments that metastable oxygen-condensed local structures were formed in the early stage of Si(110) oxidation at room temperature. After thermal annealing of 15 min at 573 K, highly-oxidized components of Si2p spectrum, Si
and Si
, were enhanced whereas Si
was decreased. This is due to structural relaxation of the strained metastable oxidation structures on the surface and following change to stable highly-oxidized structures. Furthermore, the structural change from the metastable structure in the surface oxidized at room temperature to the stable cluster structure was directly observed via STM.
Okada, Koichi*; Kondo, Keitaro; Ochiai, Kentaro; Sato, Satoshi; Konno, Chikara; Okamoto, Atsushi*; Kobuchi, Takashi*; Kitajima, Sumio*; Sasao, Mamiko*
no journal, ,
no abstracts in English
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Ultra-thin oxide layer formation processes at Si(110) surface has been studied by using real-time photoemission spectroscopy with synchrotron radiation. Distribution of Si suboxides in the one mono layer oxide has been analyzed quantitatively and Si-O bonding configurations have been considered. Analyses for Si2p photoemission spectra, which were observed in the one mono layer oxide formed at 873 K and O
pressure of 1.0
10
Pa on the Si(110) surface, resulted in avandance of an Si
suboxide component whereas an Si
component was dominant in the oxidation of Si(001) surface. The Si(110) surface consists of dense A bonds, which combine Si atoms in the same layer, and dilute B bonds, which combine Si atoms in the neibouring layers. Remaning of a part of the A bonds, which is easy to be distorted, as non-oxidized parts causes the dominant Si
component formation.