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irradiated with heavy ions in the energy range of 
1MeV/uIshikawa, Norito; Sonoda, Takeshi*; Sawabe, Takashi*; Sugai, Hiroyuki*; Sataka, Masao*
Nuclear Instruments and Methods in Physics Research B, 314, p.180 - 184, 2013/11
Times Cited Count：20 Percentile：82.27(Instruments & Instrumentation)In order to investigate electronic stopping power dependence of ion-track size in UO, ion-tracks in UO irradiated with various ions with the specific energy in the order of 1 MeV/u have been observed by a transmission electron microscope. The ion-tracksize shows monotonic increase as a function of the electronic stopping power. Theion-track size obtained for UO is smaller than that obtained for CeO, although these two compounds have same crystallographic structure and similar thermal properties. The ion-track sizes for irradiations with ions having relatively low energy of about1 MeV/u are smaller than those expected from the thermal spike models based on melting temperature criterion. The possible interpretations for the unusually smallion-tracks observed for UO are discussed.
irradiated with high-energy heavy ionsIshikawa, Norito; Sonoda, Takeshi*; Okamoto, Yoshihiro; Sawabe, Takashi*; Takegahara, Keisuke; Kosugi, Shinya*; Iwase, Akihiro*
Journal of Nuclear Materials, 419(1-3), p.392 - 396, 2011/12
Times Cited Count：10 Percentile：60.56(Materials Science, Multidisciplinary)In order to characterize the radiation damage due to ion-track formation in UO, polycrystalline samples have been irradiated with 210-MeV Xe ions, and measured with XRD (X-ray diffraction) technique using Cu X-ray. We have also tried EXAFS (extended X-ray absorption fine structure) measurement using X-ray near U L
-edge. The results show that XRD technique detects damage at relatively low fluence of 10
ions/m
and higher, while the irradiation-induced change of EXAFS spectra is not observed even at highest fluence of 10
ions/m. The damage detection may be critically influenced by the depth profile of X-ray penetration.
by means of synchrotron radiation X-ray photoelectron spectroscopyIwase, Akihiro*; Ono, Hirotaka*; Ishikawa, Norito; Baba, Yuji; Hirao, Norie; Sonoda, Takeshi*; Kinoshita, Motoyasu*
Nuclear Instruments and Methods in Physics Research B, 267(6), p.969 - 972, 2009/03
Times Cited Count：37 Percentile：90.94(Instruments & Instrumentation)To study the effects of swift heavy ion irradiation on cerium dioxide (CeO), CeO sintered pellets were irradiated with 200 MeV Xe ions at room temperature. For irradiated and unirradiated samples, the spectra of X-ray photoelectron spectroscopy (XPS) were measured. XPS spectra for the irradiated samples show that the valence state of Ce atoms partly changes from +4 to +3. The amount of Ce
state was quantitatively obtained as a function of ion-fluence. The relative amount of oxygen atom displacements, which are accompanied by the decrease in Ce valence state, is 3-5%. This value is too large to be explained in terms of elastic interactions between CeO and 200 MeV ions. The experimental result suggests the contribution of 200 MeV Xe induced electronic excitation to the displacements of oxygen atoms.
Sonoda, Takeshi*; Kinoshita, Motoyasu*; Ishikawa, Norito; Sataka, Masao; Chimi, Yasuhiro; Okubo, Nariaki; Iwase, Akihiro*; Yasunaga, Kazufumi*
Nuclear Instruments and Methods in Physics Research B, 266(12-13), p.2882 - 2886, 2008/06
Times Cited Count：31 Percentile：86.74(Instruments & Instrumentation)High-energy particle irradiation effects of CeO is investigated using electron microscopy. It is found that ion track is formed only when the electronic energy transfer exceeds 16 keV/nm.
Ono, Hirotaka*; Iwase, Akihiro*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Ishikawa, Norito; Baba, Yuji; Hirao, Norie; Sonoda, Takeshi*; Kinoshita, Motoyasu
Nuclear Instruments and Methods in Physics Research B, 266(12-13), p.3013 - 3017, 2008/06
Times Cited Count：60 Percentile：96.05(Instruments & Instrumentation)Radiation damage of CeO irradiated with 200MeV Xe is characterized by EXAFS and XPS measurement. It is found that oxygen deficiencies are created after the irradiation, and charge state of Ce is changed from +4 to +3.
by using synchrotron radiation X-ray absorption spectroscopy; As a simulation study for radiation damage in high-burnup light water reactor fuelsOno, Hirotaka*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Ishikawa, Norito; Sonoda, Takeshi*; Kinoshita, Motoyasu*; Iwase, Akihiro*
Materials Research Society Symposium Proceedings, Vol.1043, p.179 - 183, 2008/00
CeO thin films were irradiated with 200 MeV Xe ions. Effects of the irradiation were studied by using Extended X-ray Absorption Fine Structure (EXAFS) measurement at SPring-8 synchrotron radiation facility. EXAFS spectra for the irradiated thin films near the Ce K-edge show that the coordination number for oxygen atoms around Ce atom decreases and that the Ce-O Debye-Waller factor increases by the irradiation. The atomic distance between oxygen atom and Ce atom does not vary within the accuracy of EXAFS measurement. The effect of high density electronic excitation on the structure of CeO is discussed.
Kinoshita, Motoyasu*; Geng, H. Y.*; Chen, Y.*; Kaneta, Yasunori*; Iwasawa, Misako*; Onuma, Toshiharu*; Sonoda, Takeshi*; Yasunaga, Kazufumi*; Matsumura, Sho*; Yasuda, Kazuhiro*; et al.
Proceedings of 2006 International Meeting on LWR Fuel Performance (TopFuel 2006) (CD-ROM), p.248 - 254, 2006/10
The New Crossover Project (NXO) is studying effect of fission irradiation on fuel material that research activity is crossing over universities, national and private laboratories. Simulation studies are being performed to find principal and triggering processes of the rim-structure formation in high burnup LWR fuel pellet, using accelerator irradiation and computational calculations. Accelerator irradiation, high energy electron irradiation, fission energy particle beam and ion implantation (ragegas atoms) and combined overlapping irradiations are being performed. For the target of irradiation, CeO isused as simulation of nuclear fuel. The initial results were such as planar structure made by Oxygen defects created by high energy electrons, and surface modification similar to grain-sub-division created by high fluence high energy particle irradiations.
Abe, Hiroaki; *; Kinoshita, Chiken*; Naramoto, Hiroshi
Nuclear Instruments and Methods in Physics Research B, 127-128, p.176 - 180, 1997/00
Times Cited Count：11 Percentile：65.45(Instruments & Instrumentation)no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*; *; *
Annu. Rep., HVEM LAB., Kyushu Univ., 0(17), p.17 - 18, 1993/00
no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*; *; *
Proc. Jpn. Acad., Ser. B, 69(7), p.173 - 178, 1993/00
no abstracts in English
Sataka, Masao; Ishikawa, Norito; Chimi, Yasuhiro; Okubo, Nariaki; Sonoda, Takeshi*; Matsumura, Sho*; Yasuda, Kazuhiro*; Yasunaga, Kazufumi*; Shiiyama, Kenichi*; Abe, Hiroaki*; et al.
no journal, ,
no abstracts in English
Matsumura, Sho*; Yasuda, Kazuhiro*; Yasunaga, Kazufumi*; Shiiyama, Kenichi*; Sonoda, Takeshi*; Abe, Hiroaki*; Iwai, Takeo*; Sataka, Masao; Ishikawa, Norito; Chimi, Yasuhiro; et al.
no journal, ,
no abstracts in English
pre-implanted with Xe ionsYasunaga, Kazufumi*; Sonoda, Takeshi*; Yasuda, Kazuhiro*; Shiiyama, Kenichi*; Matsumura, Sho*; Sataka, Masao; Ishikawa, Norito; Chimi, Yasuhiro; Okubo, Nariaki; Iwase, Akihiro*; et al.
no journal, ,
Irradiation experiments were performed for CeO using ion accelerators. CeO were first pre-implanted with 2at.% Xe and furthermore heavily irradiated with high-energy heavy ions, and as a result restructuring of dislocation has been found.
" by means of synchrotron radiationOno, Hirotaka*; Maeda, Nobuhiro*; Nakagawa, Sho*; Zushi, Yoshihiro*; Iwase, Akihiro*; Baba, Yuji; Hirao, Norie*; Ishikawa, Norito; Chimi, Yasuhiro; Sataka, Masao; et al.
no journal, ,
X-ray absorption spectroscopy is applied for evaluation of heavy ion irradiation effects in sim-fuel CeO in order to investigate the radiation damage of nuclear fuels bombarded by fission fragments. It is found that oxygen atoms are displaced via elastic displacement process, and the charge state of Ce changes from 4+ to 3+.
Sonoda, Takeshi*; Ishikawa, Norito; Sataka, Masao; Okubo, Nariaki; Yasunaga, Kazufumi*; Yasuda, Kazuhiro*; Shiiyama, Kenichi*; Matsumura, Sho*; Iwase, Akihiro*; Kinoshita, Motoyasu*
no journal, ,
In order to elucidate the radiation damage in nuclear fuel, simulation material CeO has been irradiated with ions and its damage has been investigated. It is found that by 210MeV Xe irradiation subdivision of crystals is promoted, and Xe-preimplantation accelerates it.
Kinoshita, Motoyasu; Chen, Y.*; Sonoda, Takeshi*; Matsumura, Sho*; Nishiura, Yasumasa*; Iwase, Akihiro*; Nakamura, Jinichi
no journal, ,
no abstracts in English
Kinoshita, Motoyasu; Yasunaga, Kazufumi*; Sonoda, Takeshi*; Iwase, Akihiro*; Ishikawa, Norito; Sataka, Masao; Yasuda, Kazuhiro*; Matsumura, Sho*; Geng, H. Y.*; Ichinomiya, Takashi*; et al.
no journal, ,
We show the outline of achievements of New Cross Over (NXO) project. Concerning the grain subdivision of ceramics fuel at high burnup, we are trying to clarify the mechanisms and to develop the simulation methods. The main high lights are as follow as: (1) We have reproduced the grain subdivision of CeO, by means of ion implanter and TUNDEM accelerator. (2) We performed computational science study concerning the relocation of oxygen. In case of oxygen exess conditions, first principal calculation reproduced the orderring structure. TAD calculation shows that the exess oxygen compose clusters and diffuses rapidly even if low temperature.
by means of syncrotron radiation X-ray photoelectron spectroscopy and Ce K-edge EXAFS spectroscopyIwase, Akihiro*; Ono, Hirotaka*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Ishikawa, Norito; Baba, Yuji; Hirao, Norie; Sonoda, Takeshi*; Kinoshita, Motoyasu*
no journal, ,
To study the effects of swift heavy ion irradiation in cerium dioxide, the samples were irradiated with 200MeV Xe. The irradiated samples were analyzed by EXAFS measurement and XPS measurement.
Kinoshita, Motoyasu; Chen, Y.*; Abe, Hiroaki*; Nishiura, Yasumasa*; Matsumura, Sho*; Iwase, Akihiro*; Sonoda, Takeshi*; Sataka, Masao; Kaburaki, Hideo; Nakamura, Jinichi
no journal, ,
no abstracts in English
Chen, Y.*; Kaneta, Yasunori*; Geng, H. Y.*; Shang, J. C.*; Iwasawa, Misako*; Onuma, Toshiharu*; Sonoda, Takeshi*; Ichinomiya, Takashi*; Suzudo, Tomoaki; Itakura, Mitsuhiro; et al.
no journal, ,
The outcome of the New Crossover Project Study is outlined. The computational results includes the ab-initio study, molecular dynamics, statistical dynamics/thermal dynamics and meso-scopic modeling, and the experimental results given by an accelerator is also mentioned. Finally, we mention the future plans and the problems.
