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Okajima, Satoshi; Kawasaki, Nobuchika*; Fukahori, Takuya*; Kikuchi, Koichi*; Kasahara, Naoto
Dai-49-Kai Koon Kyodo Shimpojiumu Koen Rombunshu, p.85 - 89, 2011/11
no abstracts in English
Adare, 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:49.6(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.
Kawasaki, Nobuchika; Date, Shingo*; Kikuchi, Koichi*; Isobe, Nobuhiro*; Kasahara, Naoto
Nihon Kikai Gakkai M&M 2009 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM), p.535 - 536, 2009/07
The effect of ratcheting strain on creep-fatigue strength was investigated in order to adjust the strain limit. Ratcheting creep-fatigue tests were conducted at 600 C with 1 hr hold time. Creep fatigue lives did not decrease when the accumulated strain was superimposed within 5%. Therefore the effect of ratcheting on creep-fatigue strength is negligible when accumulated strain exceeds 2%.
Okajima, Satoshi; Date, Shingo*; Kawasaki, Nobuchika; Kikuchi, Koichi*; Isobe, Nobuhiro*; Kasahara, Naoto
Nihon Kikai Gakkai M&M 2009 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM), p.537 - 538, 2009/07
no abstracts in English
Takeishi, Minoru; Miyagawa, Naoto; Nakano, Masanao; Mizutani, Tomoko; Kono, Takahiko; Hiyama, Yoshinori*; Fujii, Jun*; Kikuchi, Masaaki*; Sagawa, Fumiaki*; Otani, Kazunori*
JAEA-Review 2007-041, 130 Pages, 2007/12
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear reguratory acts, and the local agreement concerning with security and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of low level liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2006, from 1st April 2006 to 31st March 2007. In this period, the concentrations and the quantities of the discharged radioactive materials from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Takeishi, Minoru; Miyagawa, Naoto; Uezu, Yasuhiro; Nakano, Masanao; Koarashi, Jun; Mizutani, Tomoko; Kono, Takahiko; Hiyama, Yoshinori*; Fujii, Yoshiyuki*; Kikuchi, Masaaki*; et al.
JAEA-Review 2006-024, 133 Pages, 2006/09
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel usage facilities, radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear reguratory acts, and the local agreement concerning with security and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of low level liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2005, from 1st April 2005 to 31th March 2006. In this period, the concentrations and the quantities of the discharged radioactive materials from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Nasu, Shoichi*; Nagata, Shinji*; Yoshii, Kiichiro*; Takahiro, Katsumi*; Kikuchi, Naoto*; Kusano, Eiji*; Moto, Shintaro*; Yamaguchi, Sadae*; Ohashi, Kentaro*; Noda, Kenji; et al.
Funtai Oyobi Fummatsu Yakin, 52(6), p.427 - 429, 2005/06
no abstracts in English
Kawasaki, Nobuchika; Kato, Shoichi; Yamauchi, Masafumi*; Nagae, Yuji; Kikuchi, Koichi*; Kasahara, Naoto
no journal, ,
To apply commercialized fast reactor, JSFR, creep fatigue evaluation method is developing to consider holding position during creep. In general thermal transients, creep hold position is intermediate position in the strain range. To consider holding position in the evaluation method, uni-axial intermediate hold type creep fatigue tests were performed and verified the evaluation method.
Kawamura, Seiko; Matsuura, Masato*; Iguchi, Satoshi*; Sasaki, Takahiko*; Taniguchi, Hiromi*; Kubota, Aiko*; Sato, Kazuhiko*; Inamura, Yasuhiro; Kikuchi, Tatsuya; Kawakita, Yukinobu; et al.
no journal, ,
A molecular dimer-Mott insulator -(BEDT-TTF)ICl is a candidate for a new type of ferroelectric system which shows a relaxor-like dielectric response. We performed inelastic neutron scattering measurements on this system by using a chopper specrometer, and observed phonon spectra in a wide wave vector ()-energy () region for the first time. Clear optical modes with the energies up to 36 meV were observed together with an acoustic phonon dispersion. The intensity of the optical mode with the lowest energy = 4.2 meV increases at a zone boundary along the * axis below = 62 K, at which a glassy ferroelectricity appears, and it further increases all over the measured range below the antiferromangetic transition temperature = 22 K. The results suggest that the lattice dynamics characterized by this optical phonon mode is significantly coupled with strongly correlated charge and spin degrees of freedom.
Kawamura, Seiko; Matsuura, Masato*; Iguchi, Satoshi*; Sasaki, Takahiko*; Taniguchi, Hiromi*; Kubota, Aiko*; Sato, Kazuhiko*; Inamura, Yasuhiro; Kikuchi, Tatsuya; Nakajima, Kenji
no journal, ,
Recently it has been reported that a molecular dimer-Mott insulator -(BEDT-TTF)ICl is a candidate of a new type of ferroelectric system which shows a relaxor-like dielectric response. The system exhibits a glassy ferroelectric state below = 62 K and long-range antiferromagnetic order below = 22 K. We have performed inelastic neutron scattering experiments on this system by using a chopper spectrometer AMATERAS installed at BL14 in MLF. The phonon intensity at 18 and 21 meV decreases with lowering temperature, while that at 13.5 meV increases. We have already found that a period-doubled optical phonon mode at 4.2 meV is enhanced below around and then is suppressed below , indicating significant relationship to both charge and spin dynamics. In sharp contrast to this low-energy mode, the intensity of the optical mode at 18 meV decreases below to reach a constant value at a low temperature.
Kawamura, Seiko; Matsuura, Masato*; Iguchi, Satoshi*; Sasaki, Takahiko*; Taniguchi, Hiromi*; Kubota, Aiko*; Sato, Kazuhiko*; Inamura, Yasuhiro; Kikuchi, Tatsuya*; Nakajima, Kenji
no journal, ,
It has been reported that in a molecular dimer-Mott insulator -(BEDT-TTF)ICl shows a relaxor-like dielectric response. The system exhibits a glassy ferroelectric state associated with charge disproportionation within the dimer, where a hole ( = 1/2) is localized, below = 62K, and a long-range antiferromagnetic order below = 22K. For such molecule-based materials, it is expected that low-energy phonon modes are coupled with spin/charge degrees of freedom. In order to observe the phonon modes in this system, we have performed inelastic neutron scattering measurements in a wide wave-vector and energy region using a chopper spectrometer AMATERAS at J-PARC MLF. The lowest energy mode shows remarkable temperature dependence of its intensity, while any softening is not observed. The result suggests that this phonon mode reflects changes in the spin/charge dynamics.
Kawamura, Seiko; Matsuura, Masato*; Iguchi, Satoshi*; Sasaki, Takahiko*; Taniguchi, Hiromi*; Kubota, Aiko*; Sato, Kazuhiko*; Inamura, Yasuhiro; Kikuchi, Tatsuya*; Nakajima, Kenji
no journal, ,
-(BEDT-TTF)ICl is an organic dimer-Mott insulator which exhibits a glassy ferroelectric state below = 62K and an antiferromagnetic order below = 22K. It is expected in such molecule-based materials that low-energy phonon modes lie in the energy region of charge and spin, and then the lattice is expected to couple with charge and spin degrees of freedom. To observe such phonon modes in this system, we have performed inelastic neutron scattering study using a chopper spectrometer AMATERAS installed at J-PARC MLF. The system shows the lowest-energy optical phonon mode at = 4.2 meV. which is significantly related to the charge degree of freedom. Analyzing the data more in detail, the intensity of the 4.2 meV-mode monotonically increases with lowering temperature toward , becomes constant below and drastically increases below . The behavior of the optical phonons at some representative positions are reported.
Kawakita, Yukinobu; Li, B.; Yonemura, Masao*; Shibata, Kaoru; Matsuura, Masato*; Yamada, Takeshi*; Kikuchi, Tatsuya*; Kawamura, Seiko; Nakajima, Kenji
no journal, ,
There are many energy materials where randomness makes a key role to express their functionality. Among such energy materials, studies on superionic conductors and their molten salt, thermoelectric material and photo-voltaic material by quasielastic and inelastic neutron scattering measurements which were performed at a public beamline of BL02 DNA and BL14 AMATERAS neutron instruments installed in Materials and Life Science Experimental Facility (MLF), J-PARC, will be introduced.
Kawakita, Yukinobu; Li, B.; Kawasaki, Takuro; Kikuchi, Tatsuya*; Kiyanagi, Ryoji; Inamura, Yasuhiro; Ohara, Takashi; Shibata, Kaoru; Kofu, Maiko; Nakamura, Mitsutaka; et al.
no journal, ,
Research results obtained in JAEA Project Research "Mechanism of the function expression caused by disordered structure" will be focused in this presentation. The purpose of this project is to reveal mechanism of the function expression of functional materials where randomness involved in crystalline structure plays an key role, by applying the method and analyses frequently used in random material physics. We will report the results of liquid bismuth with complex structure which was investigated by time-space correlation function, and low thermal conductivity in layered thermoelectric material and next-generation solar cell which was investigated by neutron inelastic scattering measurements.
Kofu, Maiko; Kajiwara, Takashi*; Kawamura, Seiko; Kikuchi, Tatsuya*; Nakajima, Kenji; Matsuura, Masato*; Shibata, Kaoru; Nagao, Michihiro*; Yamamuro, Osamu*
no journal, ,
no abstracts in English
Kawakita, Yukinobu; Kikuchi, Tatsuya*; Matsuura, Masato*; Kawasaki, Takuro; Kofu, Maiko; Tahara, Shuta*
no journal, ,
Materials and Life Science Experimental Facility (MLF) at J-PARC gives opportunities to use pulsed neutron beam to material science including fast ionic diffusion phenomena. DNA and AMATERAS spectrometers in MLF are quite useful to study atomic diffusion directly by quasielastic neutron scattering. We will focus relatively new analysis and experimental methods in this presentation such as mode distribution analysis and deduction of time-space correlation function which are both model free analysis, and possibility to detect an ionic channel in single crystal, with a few examples.