Papers Published in Journals
-Research results below have been sorted by order of journals name.
-Sorry, some research results below have no English abstract.

October 2005

330810
Wandering in color-space; Why is the life of pentaquark is so long ?
Maezawa, Yu*; Maruyama, Toshiki; Itagaki, Naoyuki*; Hatsuda, Tetsuo*
Acta Physica Hungarica A 22(1-2), p.61-68(2005) ; (JAERI-J 22071)
 
330811
Simulations of an accelerator-based shielding experiment using the particle and heavy-ion transport code system PHITS
Sato, Tatsuhiko; Sihver, L.*; Iwase, Hiroshi*; Nakashima, Hiroshi; Niita, Koji*
Advances in Space Research 35(2), p.208-213(2005) ; (JAERI-J 22072)
 In order to estimate the biological effects of HZE particles, an accurate knowledge of the physics of interaction of HZE particles is necessary. Since the heavy ion transport problem is a complex one, there is a need for both experimental and theoretical studies to develop accurate transport models. RIST and JAERI (Japan), GSI (Germany) and Chalmers (Sweden) are therefore currently developing and bench marking the General-Purpose Particle and Heavy-Ion Transport code System (PHITS). In this paper, we report simulations of an accelerator-based shielding experiment, in which a beam of 1 GeV/n Fe-ions has passed through thin slabs of polyethylene, Al, and Pb at an acceptance angle up to 4& ordm.
330812
Preparation and characterization of magnesium-silicon based oxide coating on high-crystalline SiC fiber as an interphase in SiC/SiC composite
Igawa, Naoki; Taguchi, Tomitsugu; Yamada, Reiji; Ishii, Yoshinobu; Jitsukawa, Shiro
Ceramic Engineering and Science Proceedings 26(2), p.27-34(2005) ; (JAERI-J 22073)
 
330813
Improved direct bonding method of Nd:YVO4 and YVO4 laser crystals
Sugiyama, Akira; Nara, Yasunaga
Ceramics International 31(8), p.1085-1090(2005) ; (JAERI-J 22074)
 We succeeded in the fabrication of bonded laser crystals composed of a neodymium-doped YVO4 laser crystal (Nd:YVO4) and its host crystals YVO4 by a newly developed dry etching technique using an argon ion beam. The optical distortion caused by the bonded interface of size 5 mm × 6 mm was estimated to be 0.05-wave at 633 nm. From the comparison of laser performance pumped by a laser diode, the bonded crystals could increase the laser output power by nearly twice that of the non-bonded crystals with the same degree of polarization of 99.2 %. To analyze the mechanism of the enhanced reduction of the thermal load in the bonded crystals, numerical simulations with a finite-element method were also performed.
330814
Novel separation system of trivalent actinides-combined effects of substituted tris(2-pyridylmethyl)amine ligand and hydrophobic counter-anion
Ishimori, Kenichiro*; Watanabe, Masayuki; Kimura, Takaumi; Yaita, Tsuyoshi; Yamada, Takashi*; Kataoka, Yumiko*; Shinoda, Satoshi*; Tsukube, Hiroshi*
Chemistry Letters 34(8), p.1112-1113(2005) ; (JAERI-J 22075)
 Stereochemical substitution on tripod ligand significantly offered efficient separation of trivalent actinides from trivalent lanthanides. Liquid-liquid extraction using chiral tris(2-pyridylmethyl)amine ligands as an extractant exhibited high efficiency and selectivity for trivalent actinides. A combination of chiral ligand and 2-bromodecanoic acid further enhanced extraction performance for trivalent actinides.
330815
Sedimentation of substitutional solute atoms in condensed matter; New type of diffusion
Mashimo, Tsutomu
Defect and Diffusion Forum 237-240(1), p.30-37(2005) ; (JAERI-J 22076)
 Mega-gravity field realizes the sedimentation of even atoms, and is expected to create a nonequilibrium crystal-chemical state in condensed matter. We presented a self-consistent diffusion equation for sedimentation of atoms in condensed matter. Next, we developed an ultracentrifuge to generate strong acceleration field of over 1 million g, and, recently, succeeded in realization of the sedimentation of substitutional solute atoms in some alloys. The diffusion coefficients of sedimentation on Bi-Sb alloy were estimated to be much greater than those of conventional one. It is suggested that the sedimentation of substitutional atoms in solids or liquids can be included in a new type of diffusion, where the diffusion mechanism was yet unknown. In this article, the recent progress in the investigation of sedimentation of atoms under mega-gravity field is reviewed, and the diffusion mechanism is discussed. The application of the mega-gravity field is also discussed.
330816
Development of workstation-based CAMAC data acquisition system for JT-60 data processing system
Sato, Minoru; Tsugita, Tomonori; Oshima, Takayuki; Sakata, Shinya; Iwasaki, Keita*; Matsuda, Toshiaki; Iba, Katsuyuki; Ozeki, Takahisa
Fusion Engineering and Design 71(1-4), p.145-149(2004) ; (JAERI-J 22077)
 Data processing system in JT-60 has been used CAMAC widely for control and data acquisition of plasma diagnostic. However, it has passed over fifteen years from the operation, and the problem is caused for maintenance and function enhancement by the deterioration. Then, Mini-computer and microcomputer ,which control the CAMAC system were replaced workstation based on UNIX-OS, and these system were remodeled by developing the application software for screen control by GUI and for constructing environment of remote diagnostic through the network. In addition, CAMAC device driver for Linux has been developed in for next CAMAC control system.
330817
Natural convection heat transfer of high temperature gas in an annulus between two vertical concentric cylinders
Inaba, Yoshitomo; Zhang, Y.*; Takeda, Tetsuaki; Shiina, Yasuaki
Heat Transfer-Asian Research 34(5), p.293-308(2005) ; (JAERI-J 22078)
 Water cooling panels have been adopted as the vessel cooling system of the HTTR to cool the reactor core indirectly by natural convection and thermal radiation. In order to investigate the heat transfer characteristics of high temperature gas in a vertical annular space between the reactor pressure vessel and cooling panels of the HTTR, we carried out experiments and numerical analyses on natural convection heat transfer coupled with thermal radiation heat transfer in an annulus between two vertical concentric cylinders with the inner cylinder heated and the outer cylinder cooled. In the present experiments, Rayleigh number based on the height of the annulus ranged from 2.0×107 to 5.4×107 for helium gas and from 1.2×109 to 3.5×109 for nitrogen gas. The numerical results were in good agreement with the experimental ones regarding the surface temperatures of the heating and cooling walls. As a result of the experiments and the numerical analyses, the heat transfer coefficient of natural convection coupled with thermal radiation was obtained.
330818
Growth of ZnO nanorods on Cu implanted substrates
Takeyama, Akinori; Yamamoto, Shunya; Yoshikawa, Masahito; Ito, Hiroshi
Japanese Journal of Applied Physics, Part 1 44(1B), p.750-753(2005) ; (JAERI-J 22079)
 Pyramid shaped Cu precipitates were formed on Si (100) surface as a result of 200 keV Cu ion implantation and subsequent annealing. Then, ZnO nanorods were successfully synthesized on the Cu implanted substrates by chemical vapor transport (CVT). Hexagonal shaped nanorods with a diameter of 200 nm were grown nearly perpendicular to the Cu implanted substrate and their average density was increased as increasing that of Cu precipitates. The facts strongly indicate the Cu precipitates served as the catalytic particles for the growth of ZnO rods.
330819
Effects of ultrastrong gravitational field on the crystalline state of a Bi-Sb alloy
Huang, X.*; Mashimo, Tsutomu; Ono, Masao; Tomita, Takeshi; Sawai, Tomotsugu; Osakabe, Toyotaka; Mori, Nobuo*
Journal of Applied Physics 96(3), p.1336-1340(2004) ; (JAERI-J 22080)
 Mega-gravity field experiments were performed on the Bi70Sb30(atomic percent) alloy and pure Bi below their melting points, to investigate the change in crystalline state. For the alloy centrifuged at 191-205 °C, no change in composition was observed, and the grain sizes of the crystals decreased from several mm to tens of μm, while no distinct change in grain size was observed for the centrifuged pure Bi. The alloy centrifuged at 220-240 °C consisted of two regions with different morphologies-fine-grained crystals with grain sizes around tens of μm in the low gravity region, and large crystals with grain sizes several mm long and hundreds of μm wide along the direction of gravity in the high gravity region, where sedimentation of atoms was confirmed. The large crystals with hexagonal structures were formed by preferential crystal growth roughly along the c axes, and a large strain that increased as the gravitational field increased existed inside these crystals. Formation of this anomalous crystal state might be correlated with the sedimentation of atoms.
330820
High-injection carrier dynamics generated by MeV heavy ions impacting high-speed photodetectors
Laird, J. S.; Hirao, Toshio; Onoda, Shinobu; Ito, Hisayoshi
Journal of Applied Physics 98(1), p.013530_1-013530_14(2005) ; (JAERI-J 22081)
 
330821
Hydration structure of Y3+ and La3+ compared; An Application of metadynamics
Ikeda, Takashi; Hirata, Masaru; Kimura, Takaumi
Journal of Chemical Physics 122(24), p.244507_1-244507_5(2005) ; (JAERI-J 22082)
 We studied the hydration structures of Y3+ and La3+ in aqueous solutions by applying the metadynamics method recently introduced as a tool to explore reaction pathways based on the Car-Parrinello molecular dynamics. By employing the metal-water oxygen coordination number as a collective variable of the metadynamics a couple of aqua and chloro-aqua complexes are successfully generated within the time scales of 10 ps. The reconstructed free energy surface captures the characteristics of the hydration of the light and heavy trivalent rare-earth ions. The present study demonstrates that the metadynamics based on the Car-Parrinello molecular dynamics is a promising tool for exploring the free energy surface of complicated systems such as solutions.
330822
Formation and growth of ice XI; A Powder neutron diffraction study
Fukazawa, Hiroshi; Hoshikawa, Akinori; Yamauchi, Hiroki; Yamaguchi, Yasuo*; Ishii, Yoshinobu
Journal of Crystal Growth 282(1-2), p.251-259(2005) ; (JAERI-J 22083)
 We measured neutron diffraction profiles of powdered KOD-doped D2O ice to investigate the formation and growth of ice XI, a deuterium-ordered phase of ice, from ice Ih, a disordered phase. During the measurements, the ice was annealed at 57 K for about 17 h, and then warmed up and kept at 68 K for about 55 h, which are below the transition temperature Tc = 76 K. The diffraction profiles for the doped ice at 57 K did not change with time and were close to those for ice Ih with the deuterium-disordered arrangement. However, when the temperature increased from 57 K to 68 K, the diffraction profiles changed. We carried out the Rietveld analysis with the parameters for a two-phase model to obtain the structural evidence of the appearance and the growth of ice XI. The analysis provided evidence of ice XI as space group Cmc21 at 68 K. The temporal increase of the mass fraction of ice XI showed that nucleation of ice XI began just after warming up to 68 K. Then ice XI grew for several days in the doped ice. The study provides the first structural observation of the growth of ice XI.
330823
Ultrahigh CHF prediction for subcooled flow boiling based on homogenous nucleation mechanism
Liu, W.; Nariai, Hideki*
Journal of Heat Transfer 127(2), p.149-158(2005) ; (JAERI-J 22084)
 Homogeneous nucleation, although being discounted as a mechanism for vapor formation for water in most conditions, is found being possible to occur under some extreme conditions in subcooled flow boiling. In this paper, firstly, the existence of the homogeneous nucleation governed condition is indicated. Followed, a criterion is developed to judge a given working condition is the conventional one or the homogeneous nucleation governed one. With the criterion, subcooled flow boiling data are categorized and typical homogeneous nucleation governed datasets are listed. CHF triggering mechanism for the homogeneous nucleation governed condition is proposed and verified. Parametric trends of the CHF, in terms of mass flux, pressure, inlet subcooling, channel diameter and the ratio of heated length to diameter are also studied.
330824
DPA Calculation in Japanese Spallation Neutron Source
Harada, Masahide; Watanabe, Noboru; Konno, Chikara; Meigo, Shinichiro; Ikeda, Yujiro; Niita, Koji*
Journal of Nuclear Materials 343(1-3), p.197-204(2005) ; (JAERI-J 22085)
 For a construction of maintenance and storage scenarios for JSNS, lives of structure material need to be estimated. DPA (Displacement per Atom) was a major index of radiation damage. So we evaluated DPA value of each component. Function of the DPA calculation was equipped to the PHITS code, which was particle and heavy ion transport code. For DPA calculation, displacement cross section was necessary. Displacement cross sections of neutron below 150 MeV were processed by the NJOY code from LA150 library and those of neutron above 150MeV and proton in the all energy region were obtained from energies of fragments calculated in the PHITS. By using the PHITS, we calculated DPA values and DPA mapping. We obtained that the peak DPA values at end of 5000MWh operation were 4.1 for target vessel, 2.8 for reflector and moderator vessels, and 0.4 for proton beam windows, respectively. We estimated the target life at 1 year and the moderator life at 6 year.
330825
Effect of ion irradiation and implantation of H and He on the corrosion behavior of austenitic stainless steel
Nemoto, Yoshiyuki; Miwa, Yukio; Kaji, Yoshiyuki; Tsukada, Takashi
Journal of Nuclear Materials 343(1-3), p.313-317(2005) ; (JAERI-J 22086)
 The aim of this work is to evaluate corrosion behavior of irradiated materials these would be used in spallation neutron sources. Solution annealed high purity Fe-18Cr-12Ni specimens were used in this study. Ni3+, H+ and He2+ ions were irradiated at 473 to 773K. After corrosion procedure, the specimens were examined with atomic force microscope (AFM) to evaluate corrosion behavior. It was shown that the corroded volume of irradiated area increased with radiation damage. Higher H content at lower temperature accelerated corrosion, but H at higher temperature did not accelerate corrosion. He suppressed corrosion, and corroded volume was larger for the specimens irradiated at higher temperature than these at lower temperature. It is suggested from this study that H and He affect the corrosion behavior of irradiated alloy.
330826
Determination of uranium and rare-earth metals separation coefficients in LiCl-KCl melt by electrochemical transient techniques
Kuznetsov, S. A.*; Hayashi, Hirokazu; Minato, Kazuo; Gaune-Escard, M.*
Journal of Nuclear Materials 344(1-3), p.169-172(2005) ; (JAERI-J 22087)
 The knowledge of separation coefficients of actinides and rare-earth metals is important for developing pyrometallurgical process of spent nuclear fuel. Electrochemical experiments were carried out at 723-823 K to estimate separation coefficients in LiCl-KCl eutectic melt containing uranium and lanthanum trichlorides. Uranium and lanthanum separation coefficients is calcurated with the voltammetric peak potentials of U (III) and La (III), their concentration in the melt and kinetic parameters for U(III) discharge such as diffusion coefficients, and standard rate constants of charge transfer. The diffusion coefficients of U (III) were determined by some electrochemical measurements. The standard rate constants of charge transfer for electroreduction of uranium U(III) +3e- =U were calculated by impedance spectroscopy method.
330827
Evaluation of γ-ray dose components in criticality accident situations
Sono, Hiroki; Yanagisawa, Hiroshi*; Ono, Akio*; Kojima, Takuji; Soramasu, Noboru*
Journal of Nuclear Science and Technology 42(8), p.678-687(2005) ; (JAERI-J 22088)
 Component analysis of γ-ray doses in criticality accident situations is indispensable for further understanding on emission behavior of γ-rays and accurate evaluation of external exposure to human bodies. Such dose components were evaluated, categorizing γ-rays into four components: prompt, delayed, pseudo components in the period of criticality, and a residual component in the period after the termination of criticality. This evaluation was performed by the combination of dosimetry experiments at the TRACY facility using a thermoluminescent dosimeter (TLD) made of lithium tetra borate and computational analyses using a Monte Carlo code. The evaluation confirmed that the dose proportions of the above components varied with the distance from the TRACY core tank. This variation was due to the difference in attenuation of the individual components with the distance from the core tank. The evaluated dose proportions quantitatively clarified the contribution of the pseudo and the residual components to be excluded for accurate evaluation of γ-ray exposure.
330828
The Recommended k0-factors for neutron-induced prompt γ-ray analysis and the prompt γ-ray emission probabilities
Matsue, Hideaki; Yonezawa, Chushiro
Journal of Radioanalytical and Nuclear Chemistry 262(1), p.49-55(2004) ; (JAERI-J 22089)
 The recommended k0 factors for 81 γ-lines of 24 elements, which are useful for neutron induced prompt γ-ray analysis (PGA) and are not influenced by neutron spectrum difference, were obtained from the k0 factors measured with the cold and thermal guided neutron beams of JRR-3M by statistical calculation. The prompt γ-ray emission probabilities were derived from the recommended k0-factors using atomic weight, isotopic abundance and thermal neutron cross-section of other nuclear constants consisting the k0 factors, for which one can obtain accurate data. The derived γ-ray emission probabilities for the light elements (H to Ca) well agreed within ±10% with those of the ENSDF, which reflect recent data, which the agreements for heavy elements (Ti to Pb) were ±40% with those of the ENSDF, which are still composed of old data.
330829
Gas release of SiC implanted with deuterium or helium
Aihara, Jun; Sawa, Kazuhiro; Furuya, Yoshio*; Hojo, Tomohiro*; Furuno, Shigemi*; Yamamoto, Hiroyuki; Hojo, Kiichi; Ishihara, Masahiro
Journal of the American Ceramic Society 88(8), p.2319-2321(2005) ; (JAERI-J 22090)
 
330830
High energy-resolution inelastic neutron scattering experiments on triplet bound state excitations in SrCu2(BO3)2
Aso, Naofumi*; Kageyama, Hiroshi*; Nukui, Katsuyuki*; Nishi, Masakazu*; Kadowaki, Hiroaki*; Ueda, Yutaka*; Kakurai, Kazuhisa
Journal of the Physical Society of Japan 74(8), p.2189-2192(2005) ; (JAERI-J 22091)
 
330831
Single crystal growth and fermi surface properties of an antiferromagnet UPdGa5
Ikeda, Shugo; Matsuda, Tatsuma; Haga, Yoshinori; Yamamoto, Etsuji; Nakashima, Miho*; Kirita, Shingo*; Kobayashi, Tatsuo*; Hedo, Masato*; Uwatoko, Yoshiya*; Yamagami, Hiroshi*; Shishido, Hiroaki*; Ueda, Taiki*; Settai, Rikio*; Onuki, Yoshichika
Journal of the Physical Society of Japan 74(8), p.2277-2281(2005) ; (JAERI-J 22092)
 We have succeeded in growing a high-quality single crystal of an antiferromagnet UPdGa5 by the Ga-flux method with the off-stoichiometric composition of U : Pd : Ga = 1 : 2 : 7.3. The electronic state has been investigated by the de Haas-van Alphen experiment, indicating the similar cylindrical Fermi surfaces as in an antiferromagnet UPtGa5. We have also studied the pressure effect by measuring the electrical resistivity. The Néel temperature decreases with increasing pressure and becomes zero at 3.1 GPa. The antiferromagnetic state is changed into the paramagnetic state above 3.1 GPa.
330832
Analytical study on biaxial strength of structural ceramics under tension-compression condition
Hanawa, Satoshi; Ishihara, Masahiro; Motohashi, Yoshinobu*
Key Engineering Materials 297-300, p.40-46(2005) ; (JAERI-J 22093)
 
330833
Anisotropic deformation effect on the fracture of core components made of two-dimensional C/C composite
Sumita, Junya; Shibata, Taiju; Ishihara, Masahiro; Iyoku, Tatsuo; Tsuji, Nobumasa*
Key Engineering Materials 297-300, p.143-147(2005) ; (JAERI-J 22094)
 
330834
Buckling fracture of two-dimensional carbon-fiber reinforced carbon-matrix composite
Ishihara, Masahiro; Yamaji, Masatoshi*; Baba, Shinichi; Hanawa, Satoshi
Key Engineering Materials 297-300, p.201-206(2005) ; (JAERI-J 22095)
 
330835
Basic concept on structural design criteria for zirconia ceramics applying to nuclear components
Shibata, Taiju; Sumita, Junya; Baba, Shinichi; Yamaji, Masatoshi*; Ishihara, Masahiro; Iyoku, Tatsuo; Tsuji, Nobumasa*
Key Engineering Materials 297-300, p.728-733(2005) ; (JAERI-J 22096)
 
330836
Annealing effect of thermal conductivity on thermal stress induced fracture of nuclear graphite
Sumita, Junya; Shibata, Taiju; Ishihara, Masahiro; Iyoku, Tatsuo; Tsuji, Nobumasa*
Key Engineering Materials 297-300, p.1698-1703(2005) ; (JAERI-J 22097)
 
330837
Role of low order rational q-values in the ITB events in JT-60U reverse shear plasmas
Neudatchin, S. V.*; Takizuka, Tomonori; Hayashi, Nobuhiko; Isayama, Akihiko; Shirai, Hiroshi; Fujita, Takaaki; Kamada, Yutaka; Koide, Yoshihiko; Suzuki, Takahiro
Nuclear Fusion 44(9), p.945-953(2004) ; (JAERI-J 22098)
 The formation of internal transport barriers (ITBs) near q=3 surfaces in normal shear (NrS) discharges of JT-60U is known. In reverse shear (RS) JT-60U plasmas, the role of q minimum (qmin) equal to 3.5,3,2.5,2 was not obvious for ITB formation. ITB-events (non-local confinement bifurcations inside and around ITB) are found in various NrS and RS plasmas. Under sufficient heating power, ITB-events are seen at rational and not rational values of qmin. The space-time evolution of Te and Ti is similar, suggesting the same mechanism of Te and Ti transport. The temporal formation of strong ITB under passing of qmin=3 (after periodical improvements and degradations via ITB-events) in RS mode is presented. Under smaller power, ITB-events are observed only at rational values of qmin. In a weak RS shot, abrupt rise of Te is seen at qmin=3.5, while more cases of Ti rise are observed. The difference of Te and Ti evolutions seen regularly under the low power, suggests decoupling of Te and Ti transport.
330838
Stationary high confinement plasmas with large bootstrap current fraction in JT-60U
Sakamoto, Yoshiteru; Fujita, Takaaki; Ide, Shunsuke; Isayama, Akihiko; Takechi, Manabu; Suzuki, Takahiro; Takenaga, Hidenobu; Oyama, Naoyuki; Kamada, Yutaka; JT-60 Team
Nuclear Fusion 45(7), p.574-580(2005) ; (JAERI-J 22099)
 This paper reports results on the progress in stationary discharges with a large bootstrap current fraction in JT-60U towards steady-state tokamak operation. In weak shear plasma regime, high-_p ELMy H-mode discharges have been optimized under nearly full non-inductive current drive by the large bootstrap current fraction (fBS~50%) and the beam driven current fraction (fBD>40%), which was sustained for ~2.3s with stationary condition. The high confinement enhancement factor H89~2.3 (HH98y2~1.0) was also sustained under the condition of Te~Ti. In reversed shear plasma regime, the large bootstrap current fraction (fBS~75%) has been sustained for 7.4 s under nearly full non-inductive current drive condition. The high confinement enhancement factor H89~3.0 (HH98y2~1.7) was also sustained, and the profiles of current and pressure approached the stationary condition. The large bootstrap current and the off-axis beam driven current sustained this reversed q-profile. This duration was limited only by the duration of the neutral beam injection.
330839
R&D on a high energy accelerator and a large negative ion source for ITER
Inoue, Takashi; Taniguchi, Masaki; Morishita, Takatoshi; Dairaku, Masayuki; Hanada, Masaya; Imai, Tsuyoshi*; Kashiwagi, Mieko; Sakamoto, Keishi; Seki, Takayoshi*; Watanabe, Kazuhiro
Nuclear Fusion 45(8), p.790-795(2005) ; (JAERI-J 22100)
 The R&D of a 1 MeV accelerator and a large negative ion source have been carried out at JAERI. The paper presents following progress as a step toward ITER NB system. (1) Accelerator R&D: According to success in improvement of voltage holding capability, the acceleration test of H- ions up to 1 MeV class energy is in progress. H- ion beams of 1 MeV, 100 mA class have been generated with a substantial beam current density (100 A/m2), and the current density is still increasing by the ion source tuning. (2) Large ion source R&D: One of major causes that limited the NB injection performance was spatial unifomity of negative ion production in existing negative-ion based NB systems. The present study revealed that the negative ions produced in the extraction region of the source were locally destructed by fast electrons leaking through magnetic filter. Some countermeasures and their test results are also described.
330840
Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U
Oyama, Naoyuki; Sakamoto, Yoshiteru; Isayama, Akihiko; Takechi, Manabu; Gohil, P.*; Lao, L. L.*; Snyder, P. B.*; Fujita, Takaaki; Ide, Shunsuke; Kamada, Yutaka; Miura, Yukitoshi; Oikawa, Toshihiro; Suzuki, Takahiro; Takenaga, Hidenobu; Toi, Kazuo*; JT-60 Team
Nuclear Fusion 45(8), p.871-881(2005) ; (JAERI-J 22101)
 The grassy ELM is characterized by the high frequency periodic collapse up to ~kHz, which is ~15 times faster than that for type I ELM. A divertor peak heat flux due to grassy ELMs is less than 10% of that for type I ELMs. This smaller heat flux is caused by narrower radial extent of the collapse of temperature pedestal. The different radial extent between type I ELMs and grassy ELMs qualitatively agrees with the different radial distribution of the eigen function of the ideal MHD stability analysis. The ratio of ELM energy loss for grassy ELMs to the pedestal stored energy was 0.4-1%. In high triangularity regime, ELM amplitude, frequency and type can be changed from type I ELM to high frequency grassy ELM as counter plasma rotation was increased. In low triangularity regime, on the other hand, the complete ELM suppression (QH-mode) has been achieved, when the plasma position is optimized with CTR-NBIs. The existence of the edge fluctuations localized in pedestal region may reduce the pedestal pressure, and therefore the QH-mode can be sustained for long time up to 3.4s.
330841
Profile formation and sustainment of autonomous tokamak plasma with current hole configuration
Hayashi, Nobuhiko; Takizuka, Tomonori; Ozeki, Takahisa
Nuclear Fusion 45(8), p.933-941(2005) ; (JAERI-J 22102)
 We have investigated profile formation and sustainment of current hole (CH) plasma by 1.5D transport simulations with current limit model inside CH based on Axisymmetric Tri-Magnetic-Islands equilibrium. Sharp reduction of anomalous transport in RS region can reproduce JT-60U experiments. The transport becomes neoclassical-level in RS region, which results in autonomous profile formation of ITB and CH through large bootstrap current. ITB width determined by neoclassical-level transport agrees with that in JT-60U. Energy confinement inside ITB agrees with JT-60U scaling. The scaling means that core plasma inside ITB is governed by MHD equilibrium limit, i.e., autonomous limitation of energy confinement. The plasma with large CH is sustained with full current drive by bootstrap current. The plasma with small CH and small bootstrap current fraction shrinks due to penetration of inductive current. This shrink is prevented and CH size can be controlled by appropriate external CD. CH plasma is found to respond autonomically to external CD. Application of CH plasma to reactor is discussed.
330842
CsI(Tl)/Plastic phoswich detector enhanced in low-energy γ-ray detection
Yamasoto, Kotaro; Tsutsumi, Masahiro; Oishi, Tetsuya*; Yoshizawa, Michio; Yoshida, Makoto
Nuclear Instruments and Methods in Physics Research A 550(3), p.609-615(2005) ; (JAERI-J 22103)
 A phoswich detector composed of a thin plate CsI(Tl) scintillator and a plastic scintillator (BC-400) has been designed and evaluated to improve the sensitivity in the low-energy region of large-area plastic scintillation detector. Applicability of the CsI(Tl)/Plastic phoswich detector was examined on radioactivity measurement of massive and large-area materials. The rise-time discrimination technique was applied in order to further improve the minimum detectable activity in the low-energy region. On the basis of the estimation of minimum detectable activity, it was made clear that the energy range of large-area plastic scintillation detector can be expanded down to a few tens of keV by adding a thin plate CsI(Tl) scintillator.
330843
Formation of Cu precipitates by ion implantation and thermal annealing for the growth of oxide nanorods
Takeyama, Akinori; Yamamoto, Shunya; Ito, Hiroshi; Yoshikawa, Masahito
Nuclear Instruments and Methods in Physics Research B 232(1-4), p.333-337(2005) ; (JAERI-J 22104)
 Cu precipitates were formed on Si(100) by 200 keV Cu ion implantation and subsequent annealing at 773 K. The shape of the Cu precipitates evolved from a large rectangle to a small elongated pyramid with increasing annealing time. This shape evolution seemed to result from the epitaxial formation of Cu precipitates to minimize the interfacial energy between the precipitate and the Cu implanted substrate. The average density of Cu precipitates monotonously increased and the average diameter of Cu precipitates decreased with increasing annealing time up to 1 h. These indicate that the morphology, size and average density of Cu precipitates can be controlled by varying annealing time, and that Cu ion implantation and subsequent annealing were effective in producing a substrate dispersed with catalytic particles for oxide nanorods growth.
330844
Current status of adsorbent for metal ions with radiation grafting and crosslinking techniques
Seko, Noriaki; Tamada, Masao; Yoshii, Fumio
Nuclear Instruments and Methods in Physics Research B 236(1-4), p.21-29(2005) ; (JAERI-J 22105)
 Removal of toxic metals from streaming water and ground water is important task to preserve environment. Radiation processings of grafting and crosslinking can synthesis adsorbent having high performances. Graft adsorbent can be synthesized by using the conventional polymer like polyethylene having variety shapes such as membrane, cloth, and fiber. Especially, the obtained fibrous adsorbent has 100 times higher rate of adsorption than that of commercialized resin. Novel fibrous adsorption for arsenic was synthesized by direct grafting of phosphoric monomer and following zirconium-loading. Fibrous adsorbents of amidoxime and iminodiacetate were applied to the removal of cadmium from the scallop waste. Furthermore, the amidoxime adsorbent is useful to recover rare metal such as uranium and vanadium in seawater. Crosslinked natural polymers like chitin-chitosan in the paste-like state are applicable for the metal adsorbent. This adsorbent can be biodegraded after usage.
330845
Application of poly(lactic acid) modified by radiation crosslinking
Nagasawa, Naotsugu; Kaneda, Ayako*; Kanazawa, Shinichi*; Yagi, Toshiaki; Mitomo, Hiroshi*; Yoshii, Fumio; Tamada, Masao
Nuclear Instruments and Methods in Physics Research B 236(1-4), p.611-616(2005) ; (JAERI-J 22106)
 
330846
Adsorption of metal ions by carboxymethylchitin and carboxymethylchitosan hydrogels
Wasikiewicz, J. M.; Nagasawa, Naotsugu; Tamada, Masao; Mitomo, Hiroshi*; Yoshii, Fumio
Nuclear Instruments and Methods in Physics Research B 236(1-4), p.617-623(2005) ; (JAERI-J 22107)
 The absorption ability of various metal ions into EB - radiation crosslinked carboxymethylchitin and carboxymethylchitosan has been investigated. The highest adsorption of Scandium and Gold has been obtained for carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts), respectively. Kinetic studies showed that adsorption of most of the metal ions occur in a relatively short period of time (2 hours). Detail investigation of adsorption of gold ions has been carried out for both hydrogels. The maximum uptake of Au cations, based on Langmuir equation was determined to be 37.59 mg/g for CMChts and 11.86 mg/g for CMCht. Both hydrogels indicate favorable adsorption of gold cations.
330847
Precision hfs of 126Cs(T1/2 = 1.63 m) by ABMR
Pinard, J.*; Duong, H. T.*; Marescaux, D.*; Stroke, H. H.*; Redi, O.*; Gustafsson, M.*; Nilsson, T.*; Matsuki, S.*; Kishimoto, Yasuaki*; Kominato, K.*; Ogawa, I.*; Shibata, M.*; Tada, M.*; Persson, J. R.*; Nojiri, Y.*; Momota, S.*; Inamura, T. T.*; Wakasugi, M.*; Juncar, P.*; Murayama, T.*; Nomura, T.*; Koizumi, Mitsuo; ISOLDE Collaboration*
Nuclear Physics A 753(1-2), p.3-12(2005) ; (JAERI-J 22108)
 The hfs separation Δν of 126Cs(T1/2 = 1.63 m) in the 6s 2S1/2 ground state was obtained in a precision measurement near zero magnetic field by means of atomic beam magnetic resonance with laser optical pumping on-line with the CERN-PSB-ISOLDE mass separator. The result, Δν = 3629.514(0.001) MHz, corrects significantly a previous published value from a high-field experiment. With our result, the precision of the nuclear magnetic moment, μ(126Cs)~ 0.776 μN, is now limited by the influence of extended nuclear structure on the hfs (the Bohr-Weisskopf effect).
330848
Benchmark experiments of thermal neutron and capture γ-ray distributions in concrete using 252Cf
Asano, Yoshihiro; Sugita, Takeshi*; Hirose, Hideyuki; Suzaki,Takenori
Nuclear Science and Engineering 151(2), p.251-259(2005) ; (JAERI-J 22109)
 
330849
Effect of orbital fluctuations on magnetic properties of f-electron systems
Hotta, Takashi
Physica B; Condensed Matter 359-361, p.1003-1005(2005) ; (JAERI-J 22110)
 In order to understand magnetic properties of filled skutterudite materials, we evaluate magnetic susceptibility of the Anderson model with orbital degeneracy by using the numerical renormalization group method. Even when the local ground state is Γ1, magnetic fluctuations significantly remain, if Γ4(2) is the excited state with small excitation energy, as experimentally proposed for Pr-based filled skutterudite compounds.
330850
Observation of strong soft-X-ray amplification at 8.8 nm in the transient collisional-excitaion scheme
Kawachi, Tetsuya; Sasaki, Akira; Tanaka, Momoko; Kishimoto, Maki; Hasegawa, Noboru; Nagashima, Keisuke; Koike, Masato; Daido, Hiroyuki; Kato, Yoshiaki
Physical Review A 69(3), p.033805_1-033805_4(2004) ; (JAERI-J 22111)
 We have observed strong amplification for the 4d-4p transition of the Ni-like La ions at a wavelength of 8.8nm pumped by a chirped pulse amplificatio Nd:glass laser with an energy of 18 J. In this experiment, laser pulses consist of a pre-pulse and a main pulse with duration of 200ps and 7 ps separated by 250ps. The KeV X-ray spectroscopy and theoretical calculation indicate that the plasma temperature increasesd effectively by reducing the prepulse intensity, and that the substantial gain is generated in a small overcritical region heated by the electron heat transport.
330851
Effects of hole doping on magnetic ground and excited states in the edge-sharing CuO2 chains of Ca2+xY2-xCu5O10
Matsuda, Masaaki; Kakurai, Kazuhisa; Kurogi, Shogo*; Kudo, Kazutaka*; Koike, Yoji*; Yamaguchi, Hirotaka*; Ito, Toshimitsu*; Oka, Kunihiko*
Physical Review B 71(10), p.104414_1-104414_8(2005) ; (JAERI-J 22112)
 
330852
Structural properties and phase transition of hole-orbital-ordered (C2H5NH3)2CuCl4 studied by resonant and non-resonant x-ray scatterings under high pressure
Owada, Kenji; Ishii, Kenji; Inami, Toshiya; Murakami, Yoichi; Shobu, Takahisa*; Osumi, Hiroyuki*; Ikeda, Naoshi*; Oishi, Yasuo*
Physical Review B 72(1), p.014123_1-014123_10(2005) ; (JAERI-J 22113)
 The effects of hydrostatic pressure on a structure and the corresponding resonant X-ray scattering (RXS) spectrum have been investigated for the hole-orbital-ordered compound (C2H5NH3)2CuCl4. We have found a structural phase transition at Pc=4 GPa. The reduction of the Jahn-Teller distortion (JTD) toward Pc is also ascertained by structural analyses. The gradual change in the color of the crystal is also observed in connection with the structural change near Pc. We experimentally confirmed that the RXS intensity comes from the polarization of the density of states of px and py symmetries, which is mainly dominated not by the on-site 3d-4p Coulomb interaction but by the JTD of the CuCl6 octahedron. The RXS study under a high pressure shows no striking change as JTD is suppressed by the application of pressure. On the other hand, the RXS intensity becomes zero above Pc. The results indicate that the local environment of the Cu2+ ion markedly changes. Two possible structures above Pc are proposed.
330853
Magnetic structure and metamagnetism in single crystals of NpCoGa5
Metoki, Naoto; Kaneko, Koji; Colineau, E.*; Javorsky, P.*; Aoki, Dai*; Homma, Yoshiya*; Boulet, P.*; Wastin, F.*; Shiokawa, Yoshinobu; Bernhoeft, N.*; Yamamoto, Etsuji; Onuki, Yoshichika; Rebizant, J.*; Lander, G. H.
Physical Review B 72(1), p.014460_1-014460_8(2005) ; (JAERI-J 22114)
 
330854
Crystal and magnetic structure of Ca3Ru2O7
Yoshida, Yoshiyuki*; Ikeda, Shinichi*; Matsuhata, Hirofumi*; Shirakawa, Naoki*; Lee, C. H.*; Katano, Susumu
Physical Review B 72(5), p.054412_1-054412_7(2005) ; (JAERI-J 22115)
 The crystal structure of the double-layered Ca3Ru2O7 has been studied by convergent beam electron diffraction and powder neutron diffraction. The temperature dependence of the diffraction pattern reveals that all the lattice constants jump at the first-order metal-nonmetal transition at 48 K without a change of the space group symmetry of Bb21m. In the neutron diffraction experiment, an additional magnetic reflection emerges below the Neel temperature, 56K. A possible model for this antiferromagnetic ordering is proposed, in which model magnetic moments align ferromagnetically within the double layer and antiferromagnetically between the double layers. This model reasonably explains the characteristic field dependence of the magnetoresistance observed at around 6 T.
330855
Magnetic properties of the overdoped superconductor La2-xSrxCuO4 with and without Zn impurities
Wakimoto, Shuichi; Birgeneau, R. J.*; Kagedan, A.*; Kim, H.-K.*; Swainson, I.*; Yamada, Kazuyoshi*; Zhang, H.*
Physical Review B 72(6), p.064521_1-064521_9(2005) ; (JAERI-J 22116)
 The magnetic properties of the Zn-substituted overdoped high-Tc superconductor La2-xSrxCuO4 (LSCO) have been studied by magnetization measurements and neutron scattering. Magnetization measurements reveal that for Zn-free samples with x > 0.22 a Curie term is induced implying the existence of local paramagnetic moments. A comparison of the Curie behaviour between Zn-doped and Zn-free samples signifies a general competitive relationship between the superconductivity and the induced paramagnetic moment. Neutron scattering measurements show that Zn-substitution in overdoped LSCO anomalously enhances the inelastic magnetic scattering spectra around the (π, π) position, peaking at ω ~ 7meV. These facts are discussed on the basis of a "swiss-cheese" model of Zn-substituted systems as well as a microscopic phase separation scenario in the overdoped region indicated by muon-spin-relaxation measurements.
330856
Identification of the Kπ=11/2+ isomer in neutron-rich 187W
Shizuma, Toshiyuki; Hayakawa, Takehito; Mitarai, Shiro*; Morikawa, Tsuneyasu*; Ishii, Tetsuro
Physical Review C 71(6), p.067301_1-067301_4(2005) ; (JAERI-J 22117)
 Excited states in neutron-rich 187W have been populated via deep inelastic collisions of a 630-MeV 82Se beam on a 186W target. Projectile-like fragments were measured by an annular Si detector for reaction channel selection. Delayed γ rays from target residues were detected by means of the so-called recoil shadow technique. A new isomer at 411 keV, based on the 11/2+[615] Nilsson configuration, has been identified with the half-life of 1.56(28) μs. The decay rates of the isomers are discussed in terms of the K quantum number by comparison with the systematics from the neighboring nuclei.
330857
β-decay half-lives of new neutron-rich rare-earth isotopes 159Pm, 162Sm, and 166Gd
Ichikawa, Shinichi; Asai, Masato; Tsukada, Kazuaki; Haba, Hiromitsu*; Nagame, Yuichiro; Shibata, Michihiro*; Sakama, Minoru*; Kojima, Yasuaki*
Physical Review C 71(6), p.067302_1-067302_4(2005) ; (JAERI-J 22118)
 The new neutron-rich raer-earth isotopes 159Pm, 162Sm, and 166Gd produced in the proton-induced fission of 238U were identified using the JAERI on-line isotope separator (JAERI-ISOL) coupled to a gas-jet transport sysetm. The half-lives of 159Pm, 162Sm, and 166Gd were determined to be 1.5±0.2s, 2.4±0.5s, and 4.8±1.0s, respectively. The partial decay scheme of 166Gd wes constructed for γ-γ coincidence data. The improved half-life values of 25.6±2.2s wes obtained for the previously identified isotope 166Tb. The half-lives measured in the present study are in good agreement with the theoretical predictions calculated by the second generation of the gross theory with the atomic masses evaluated by the Audei and Wapstra.
330858
Effect of charge polarization on the coulomb barrier for cold-fusion reactions
Ichikawa, Takatoshi; Iwamoto, Akira
Physical Review C 71(6), p.067601_1-067601_4(2005) ; (JAERI-J 22119)
 We estimate the decrease of the Coulomb-barrier height between colliding parters due to charge polarizations in the entrance channel for cold-fusion reactions. Since the Coulomb-repulsion force increases with increasing the proton numbers of the target and projectile such as cold-fusion reactions, it is expected that the charge distribution of the colliding nuclei is changed to some extent. The resulting charge distribution induced by this polarization decreases the interacting Coulomb energy between the colliding partners, whereas their own self energies increase due to the increase of the symmetry energy. We assume that the resulting charge displacements between protons and neutrons are the sum of the surface- and volume-charge components and estimate the extent of the charge polarization with the self energy on the basis of the droplet model. We show the difference between the charge polarization of light and heavy nuclei and the decrease of the Coulomb barrier height for synthesizing superheavy elements.
330859
29Na; Defining the edge of the island of inversion for Z=11
Tripathi, V.*; Tabor, S. L.*; Mantica, P. F.*; Hoffman, C. R.*; Wiedeking, M.*; Davies, A. D.*; Liddick, S. N.*; Mueller, W. F.*; Otsuka, Takaharu*; Stolz, A.*; Tomlin, B. E.*; Utsuno, Yutaka; Volya, A.*
Physical Review Letters 94(16), p.162501_1-162501_4(2005) ; (JAERI-J 22120)
 
330860
Momentum dependence of charge excitations in the electron-doped superconductor Nd1.85Ce0.15CuO4; A Resonant inelastic X-ray scattering study
Ishii, Kenji; Tsutsui, Kenji*; Endo, Yasuo*; Toyama, Takami*; Maekawa, Sadamichi*; Hoesch, M.; Kuzushita, Kaori; Tsubota, Masami; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi; Yamada, Kazuyoshi*
Physical Review Letters 94(20), p.207003_1-207003_4(2005) ; (JAERI-J 22121)
 We report a resonant inelastic x-ray scattering (RIXS) study of charge excitations in the electron-doped high-Tc superconductor Nd1.85Ce0.15CuO4. The intraband and interband excitations across the Fermi energy are separated for the first time by tuning the experimental conditions properly to measure charge excitations at low energy. A dispersion relation with q-dependent width emerges clearly in the intraband excitation, while the intensity of the interband excitation is concentrated around 2 eV near the zone center. The experimental results are consistent with theoretical calculation of the RIXS spectra based on the Hubbard model.
330861
Development of a thermal neutron focusing device using neutron supermirrors
Osakabe, Toyotaka; Soyama, Kazuhiko
Review of Scientific Instruments 76(7), p.073102_1-073102_5(2005) ; (JAERI-J 22122)
 Neutron focusing is an indispensable technique used to compensate for weak signals in experiments under extreme conditions with tiny samples. We describe the development of a thermal neutron focusing device for a typical triple-axis neutron spectrometer. The device has a length of 400 mm and is placed between the second collimator and the sample position. The focal length is 150 mm from the downstream end of the device. The optic has 18 pieces of the circular blade consisting of 3m NiC/Ti neutron supermirrors. The extensions of the end of each blade meet at the sample position, namely the focal point. Neutrons undergo successive reflection through the same angle from the inner surface of each blade and arrive at the sample position. The test results show that the gain of the neutron intensity at the sample position increases by a factor of two or more for the neutron energy below 30.5 meV.
330862
Quantitative modeling of photoassimilate flow in an intact plant using the Positron Emitting Tracer Imaging System (PETIS)
Matsuhashi, Shimpei; Fujimaki, Shu; Kawachi, Naoki; Sakamoto, Koichi; Ishioka, Noriko; Kume, Tamikazu
Soil Science and Plant Nutrition 51(3), p.417-423(2005) ; (JAERI-J 22123)
 
330863
Size of small Si and Ge clusters on Si(111) and Ge(111) surfaces
Asaoka, Hidehito; Cherepanov, V.*; Voigtl"ander, B.*
Surface Science 588(1-3), p.19-25(2005) ; (JAERI-J 22124)
 We determined the average size of small Si and Ge clusters con·ned to one half of a (7×7) or (5×5) unit cell of a Si or Ge(111) surface. The size of Si and Ge clusters con·ned to a Si(111)-(7×7) half unit cell was determined to be 8.3±1 atoms and 7.5±1 atoms, respectively for a growth temperature of 400 K. This is the same value within the error and shows, that the material of the clusters is less important for the cluster size. On the Ge surface it was found that the reconstruction unit cell is important for the cluster size. On the (5×5) reconstructed Ge(111) surface the Si clusters have a smaller size of 4.7±1 atoms compared to 8.2±1 atoms for Si clusters on the Ge(111)-(7×7) surface.
330864
Damage evaluation techniques for FBR and LWR structural materials based on magnetic and corrosion properties along grain boundaries
Hoshiya, Taiji*; Takaya, Shigeru*; Ueno, Fumiyoshi; Nemoto, Yoshiyuki; Nagae, Yuji*; Miwa, Yukio; Abe, Yasuhiro*; Omi, Masao; Tsukada, Takashi; Aoto, Kazumi*
Transactions of the Materials Research Society of Japan 29(4), p.1687-1690(2004) ; (JAERI-J 22125)
 JAERI and JNC have begun the cooperative research of evaluation techniques of structural material degradation in FBR and LWR, which based on magnetic and corrosion properties along grain boundaries. Magnetic method has been proposed as the one of the non-destructive detection techniques on the early stage of creep-damage before crack initiation for aged structural materials of FBRs. The effects of applied stress on natural magnetization were investigated on paramagnetic stainless steels having creep-damages. On the other hand, corrosion properties and magneto-optical characteristics of ion-irradiated stainless steels in the vicinity of grain boundaries were estimated by AFM and Kerr effect microscope, respectively. These degradations were induced by changes in characteristics in the vicinity of grain boundaries. It is found that the initial level of progressing process of damage can detect changes in magnetic and corrosion properties along grain boundaries of aged and degraded nuclear plants structural materials.
330865
Separation technologies on thermochemical water-splitting iodine-sulfur process (in Japanese)
Kubo, Shinji; Yoshida, Mitsunori; Sakurai, Makoto*; Tanaka, Kotaro*; Miyashita, Reiko*
Bunri Gijutsu 35(3), p.148-152(2005) ; (JAERI-J 22126)
 
330866
Analysis of nuclear fuel cycle related materials (in Japanese)
Sato, Soichi*; Suzuki, Toru*; Hiyama, Toshiaki*; Watanabe, Kazuo
Bunseki 2005(8), p.451-457(2005) ; (JAERI-J 22127)
 
330867
Compatibility of lithium oxide single crystals with tungsten sputtered films; The Effect of passivation films
Nasu, Shoichi*; Nagata, Shinji*; Yoshii, Kiichiro*; Takahiro, Katsumi*; Kikuchi, Naoto*; Kusano, Eiji*; Moto, Shintaro*; Yamaguchi, Sadae*; Ohashi, Kentaro*; Noda, Kenji; Shikama, Tatsuo*
Funtai Oyobi Fummatsu Yakin 52(6), p.427-429(2005) ; (JAERI-J 22128)
 
330868
Scenario to focusing polarized small-angle neutron scattering spectrometer SANS-J-II (in Japanese)
Koizumi, Satoshi; Iwase, Hiroki; Tanaka, Hirokazu; Hashimoto, Takeji; Suzuki, Junichi; Oku, Takayuki; Sasao, Hajime*; Shimizu, Hirohiko
Hamon 14(4), p.266-274(2004) ; (JAERI-J 22129)
 
330869
Investigation of perpendicular magnetic films by means of soft X-ray magnetic circular dichroism spectroscopy (in Japanese)
Agui, Akane; Mizumaki, Masaichiro*; Asahi, Toru*
Hoshako 18(4), p.215-222(2005) ; (JAERI-J 22130)
 
330870
Clustered DNA damage induced by ionizing radiaton (in Japanese)
Yokoya, Akinari; Shikazono, Naoya; Urushibara, Ayumi; Fujii, Kentaro; Akamatsu, Ken; Watanabe, Ritsuko
Hoshasen Seibutsu Kenkyu 40(2), p.168-184(2005) ; (JAERI-J 22131)
 Ionizing radiation causes modifications in a DNA molecule depending on the characteristic tack-structure in which two or more isolated lesions arise in a few nm scale (1 or 2 helical turn of DNA), known as "clustered DNA damage". These clustered DNA damages could be distinct from those by reactive oxygen species (ROS) endogenously induced on their severity of induction of biological effects such as mutation. However, the studies on the nature and repair mechanism of clustered DNA damage have still been behind because of the technical difficulties on determination of the chemical structure and yield. This article reviews some experimental evidences of the clustered DNA damages in this research field, as well as our recent progress on the studies on the clustered DNA damages using both molecular biological techniques and synchrotron spectroscopic method.
330871
Numerical visualization on a Large-scale bubbly flow in a vertical small duct (in Japanese)
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Aoki, Takayuki*
Kashika Joho 25(Suppl.1), p.435-436(2005) ; (JAERI-J 22132)
 
330872
Application of diamond to fusion plasma diagnostic (in Japanese)
Kusama, Yoshinori; Ishikawa, Masao
NEW DIAMOND 21(3), p.24-25(2005) ; (JAERI-J 22133)
 
330873
A Estimation methods of lower weight bound on neutron deep penetration problem with Monte Carlo method (in Japanese)
Sakurai, Kiyoshi; Yamamoto, Toshihiro
Nippon Genshiryoku Gakkai Wabun Rombunshi 4(2), p.172-176(2005) ; (JAERI-J 22134)
 Typical weight estimation methods with Monte Carlo method such as MCNP default, empirical formula, mono-energy neutron attenuation curve, MCNP wwg and adjoint flux are described. The mono-energy neutron attenuation curve method is proposed by authors. Weights estimated by methods except MCNP default and adjoint flux methods are compared with those calculated by MCNP wwg method.
330874
Oxidation reaction kinetics on Ti(0001) surface studied by real-time photoelectron spectroscopy (in Japanese)
Takakuwa, Yuji*; Ogawa, Shuichi*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden
Shokubai 47(5), p.352-357(2005) ; (JAERI-J 22135)
 Oxidation reactions of Ti(0001) surfaces were monitored by real-time photoelectron spectroscopy with high brilliant synchrotron radiation and He-I resonance line. An oxygen adsorption model and ultra-thin oxide layers formation processes were reviewed on the basis of time evolutions of the adsorbed oxygen amount, oxidation states, electronic states and the work function, which were obtained from photoelectron spectra for Ti 2p and O 1s core levels as well as the valence band.
330875
Development of a quake-proof information inference system by using data mining technology
Shu, Y.; Nakajima, Norihiro
Proceedings of 11th International Conference on Human-Computer Interaction (HCI International 2005) (CD-ROM) , 9p.(2005) ; (JAERI-J 22136)
 To understand the behavior of NPP (nuclear power plant) under different operating environment, JAERI is carrying out full-scaled plant simulation. As one part of full scaled plant simulation, our ongoing work is to develop an information inference system to manage and interpret NPP quake-proof data. In this paper, we proposed a hybrid data mining approach, which integrates human cognitive model in a data mining loop. Rule-based mining control agent emulated human analysts directly interacts with the data miner, analyzing and verifying the output of data miner and controlling data mining process. In additional, artificial neural network method, which is adopted as a core component of the proposed hybrid data mining method, is evolved by adding the retraining facility and explaining function for handling complicated nuclear power plant quake-proof data. To demonstrate how the method can be used as a powerful tool for extracting information relevant to plant safety and reliability, plant quake-proof testing data have been applied to the inference system.
330876
Fuels and materials researches in the HTTR project
Sawa, Kazuhiro
Proceedings of KNS-AESJ Joint Summer School 2005 for Students and Young Researchers, 2 , p.161-167(2005) ; (JAERI-J 22137)
 The fuels and materials research programs for HTGRs, which have been carried out under the HTTR Project, are described.
330877
Stress analysis of two-dimensional C/C composite components for HTGR's core restraint mechanism
Hanawa, Satoshi; Sumita, Junya; Shibata, Taiju; Ishihara, Masahiro; Iyoku, Tatsuo; Sawa, Kazuhiro
Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18) , p.600-605(2005) ; (JAERI-J 22138)
 
330878
Structural integrity assessments of helium components in the primary cooling system during the safety demonstration test using the HTTR
Sakaba, Nariaki; Tachibana, Yukio; Nakagawa, Shigeaki; Hamamoto, Shimpei
Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18) , p.4499-4511(2005) ; (JAERI-J 22139)
 Safety demonstration tests using the HTTR are now underway in order to verify the inherent safety features and to improve the safety design and evaluation technologies for HTGRs, as well as to contribute to research and development for the VHTR, which is one of the Generation IV reactor candidates. The coolant flow reduction test by running down gas circulators, which is one of the safety demonstration tests, is a simulation test of anticipated transients without scram. During the coolant flow reduction test, temperature of the high-temperature helium components and chemistry in the primary circuit are changed rapidly. This paper describes the structural integrity assessments of helium components, e.g. helium pipes, heat exchangers, during the coolant flow reduction test. From the result of this evaluation, it was found that the helium components were kept their structural integrity during temperature and chemistry transient condition in the coolant flow reduction test from the reactor power at 30%. It was also confirmed by this assessment that the coolant flow reduction test will be able to perform with its enough safety margins from the reactor power at 100%.
330879
Temperature evaluation of core components of HTGR at depressurization accident considering annealing recovery on thermal conductivity of graphite
Sumita, Junya; Shibata, Taiju; Nakagawa, Shigeaki; Hanawa, Satoshi; Iyoku, Tatsuo; Ishihara, Masahiro
Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18) , p.4822-4828(2005) ; (JAERI-J 22140)
 Graphite materials are used for structural components in High Temperature Gas-Cooled Reactor (HTGR) core because of their excellent thermo/mechanical properties. Thermal conductivity of graphite components is reduced by neutron irradiation in reactor operation. The reduced conductivity is expected to be recovered by thermal annealing effect when irradiated graphite component is heated above irradiated temperature. In the present study, temperature analyses considering the annealing effect of the HTGR core at a depressurization accident were carried out and influence of annealing effect on maximum fuel temperature was investigated. The analyses show that the annealing effect can reduce the fuel temperature about 100°C at the maximum, and it is possible to evaluate the maximum fuel temperature more appropriately. It was also shown that the core-temperature of High Temperature Engineering Test Reactor (HTTR) at the safety demonstration tests can be analyzed with the developed evaluation method considering annealing effect.
330880
Large-scale simulations of two-phase flow dynamics in fuel channels of nuclear reactor cores (in Japanese)
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Aoki, Takayuki*
Dai-24-Kai Nippon Shimyureshon Gakkai Taikai Happyo Rombunshu , p.161-164(2005) ; (JAERI-J 22141)
 
330881
Research for thermal-hydraulic performance in a tight-lattice fuel assembly, 2; Two-phase flow analysis in a fuel assembly with a large-scale simulation (in Japanese)
Takase, Kazuyuki; Yoshida, Hiroyuki; Akimoto, Hajime; Ose, Yasuo*
Nippon Konsoryu Gakkai Nenkai Koenkai 2005 Koen Rombunshu , p.231-232(2005) ; (JAERI-J 22142)
 
330882
Development of remote control JAVA tool for PLC (in Japanese)
Kawase, Masato*; Takahashi, Hiroki; Sakaki, Hironao; Ito, Yuichi*; Sugimoto, Makoto*; Watanabe, Kazuhiko*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.633-635(2005) ; (JAERI-J 22143)
 In J-PARC control System, machinery having a network controller(NTC) is operated with EPICS. A NTC can also connect with an upper level computer directly, while in EPICS, an IOC is used for communication between an upper level computer and a NTC. In case of a communication error, one must investigate the source of the error, whether it is due to the NTC. It becomes very effective if one can switch the connection method between EPICS and direct connection on an operation screen. We report on a development of a tool realizing such functionalities.
330883
Acceleration of high current and highly charged carbon beam using direct injection scheme (in Japanese)
Kashiwagi, Hirotsugu; Okamura, Masahiro*; Jameson, R. A.*; Hattori, Toshiyuki*; Hayashizaki, Noriyosu*; Sakakibara, Kazuhiko*; Takano, Jumpei*; Yamamoto, Kazuo*; Iwata, Yoshiyuki*; Fujimoto, Tetsuya*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.182-184(2005) ; (JAERI-J 22144)
 The carbon beam from a Nd-YAG laser ion source was accelerated successfully by an RFQ linac using Direct injection scheme. The "Direct injection scheme" is the way to inject an ion beam to the RFQ linac without a low energy beam transport line to avoid space charge effect due to a high intensity beam from the laser ion source. About 30mA of a carbon beam was detected by a faraday cup just behind the RFQ linac.
330884
Status of RF system for the J-PARC linac (in Japanese)
Chishiro, Etsuji; Hori, Toshihiko*; Kobayashi, Tetsuya; Suzuki, Hiroyuki*; Suganuma, Kazuaki; Yamazaki, Masayoshi*; Anami, Shozo*; Fang, Z.*; Fukuda, Shigeki*; Fukui, Yuji*; Kubota, Chikashi*; Kadokura, Eiichi*; Kawamura, Masato*; Michizono, Shinichiro*; Yamaguchi, Seiya*; Yoshida, Mitsuhiro*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.236-238(2005) ; (JAERI-J 22145)
 
330885
Present status of the 972MHZ RF test stand at JAERI 2005 (in Japanese)
Hori, Toshihiko*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Hasegawa, Kazuo; Yoshida, Mitsuhiro*; Yamaguchi, Seiya*; Anami, Shozo*; Fukuda, Shigeki*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.239-241(2005) ; (JAERI-J 22146)
 
330886
RF characteristics of J-PARC DTL3 cavity (in Japanese)
Ito, Takashi; Asano, Hiroyuki*; Morishita, Takatoshi; Kato, Takao*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*; Naito, Fujio*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.242-244(2005) ; (JAERI-J 22147)
 The third Drift Tube Linac (DTL3) is adopted for 37MeV-50MeV part of high intensity proton linac for Japan Proton Accelerator Research Complex(J-PARC). DTL3 consists of 26 full drift tubes, 2 half drift tubes and 26 post-couplers. As a result of tuning of the accelerating field of the DTL3, the resonant frequency was adjusted to 324MHz and the average accelerating field distribution was adjusted within 1%.
330887
Present status of the L3BT for J-PARC
Okawa, Tomohiro*; Ao, Hiroyuki; Ikegami, Masanori*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.251-253(2005) ; (JAERI-J 22148)
 L3BT is a beam transport line from J-PARC (Japan Proton Accelerator Research Complex) linac to the succeeding 3-GeV RCS (Rapid Cycling Synchrotron). Recently, the positions of the debunchers in L3BT are revised to optimize the momentum spread at the RCS injection. In this paper, results of the beam simulation of the L3BT with the new debuncher locations are presented. The construction status of the L3BT is also presented in brief.
330888
An Alignment of J-PARC linac (in Japanese)
Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Naito, Fujio*; Yoshino, Kazuo*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.266-268(2005) ; (JAERI-J 22149)
 J-PARC linear accelerator components are now being installed in the accelerator tunnel. Markings are placed on the floor, which act as a reference for the initial alignment at the installation. A planned and ongoing alignment schemes for the installation of linac components and watching the long term motion of the building are described.
330889
Performance study of low-level RF analog feedback control system for J-PARC linac (in Japanese)
Kobayashi, Tetsuya; Chishiro, Etsuji; Suzuki, Hiroyuki*; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Kawamura, Masato*; Fukui, Yuji*; Fang, Z.*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.320-322(2005) ; (JAERI-J 22150)
 Total System of 324MHz-Low Level RF Control for J-PARC Linac was produced and its performance study was done. In this system, in order to stabilize the Klystron output and to compensate the linearity of that, an analog feedback control system is adopted. The response function including phase characteristic (vector locus) of this feedback system was obtained by means of measurement. From this result the prospect for the transient analysis is discussed.
330890
Fabrication status for J-PARC ACS (in Japanese)
Ao, Hiroyuki; Ueno, Akira; Morishita, Takatoshi; Hasegawa, Kazuo; Yamazaki, Yoshishige ; Ikegami, Masanori*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.332-334(2005) ; (JAERI-J 22151)
 The first ACS module consists of two 5-cells ACS tanks and a 5-cells bridge cavity for the buncher module. Three RF tuners are installed to the bridge cavity for fine RF tuning. An operating frequency should be tuned to 972 MHz within the fine-tuning range before a brazing process in a factory. The tuning procedure has been studied with RF simulation analysis and cold-model measurements for ACS and bridge cells. This paper describes RF tuning results, fabrication status and related development items.
330891
Development of user interface for accelerator components database (in Japanese)
Watanabe, Kazuhiko*; Yoshikawa, Hiroshi; Sakaki, Hironao; Takahashi, Hiroki; Kawase, Masato*; Sugimoto, Makoto*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.451-453(2005) ; (JAERI-J 22152)
 In J-PARC, we manage the accelerator devices data using the relational database. It is used for managing physical value of all devices. We request the database to generate EPICS records, and the managed data must always the latest. Some data is treated by operator who doesn't have enough experience of database input. If they feel the input is difficult, the input of the database stagnates. In the worst case, the database might not be used. This paper reports the database GUI for operator who doesn't have enough experience of database.
330892
RDB system in J-PARC LINAC and its application to commissioning (in Japanese)
Sako, Hiroyuki; Sakaki, Hironao; Takahashi, Hiroki; Yoshikawa, Hiroshi; Ito, Yuichi*; Kato, Yuko*; Kamikubota, Norihiko*; Sugimoto, Makoto*; Watanabe, Kazuhiko*; Ikeda, Hiroshi*; Terashima, Yasushi*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.462-464(2005) ; (JAERI-J 22153)
 Current status of the RDB system in J-PARC LINAC is presented. The machine database records static data of devices and the control system, whereas the operation log database records a history of operation parameters. The overall design of control flow among high-level applications, simulators, and database is described. Then results of a control test of the power supply for DTQ, and a prototype test of the operation log database in MEBT1 test bench at KEK are reported. In the end, a scheme to generate simulation configuration files from RDB is shown.
330893
Summary of 3GeVRCS control system, 2 (in Japanese)
Takahashi, Hiroki; Sakaki, Hironao; Sako, Hiroyuki; Yoshikawa, Hiroshi; Ito, Yuichi*; Kato, Yuko*; Kawase, Masato*; Sugimoto, Makoto*; Watanabe, Kazuhiko*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.531-533(2005) ; (JAERI-J 22154)
 J-PARC 3GeV RCS send the beam of a different parameter to both the institutions of MLF and MR. Therefore, 3GeV RCS Control System is required unprecedented capability to supervise correctly by distinguishing the beam for MLF and MR. Following the status report last year, this report shows the status of 3GeV RCS Control System focusing on Data Acquisition system which is able to collect the synchronized data and Based Data Management system which become the basis for 3GeV RCS Control System.
330894
Single-turn extraction technique in AVF cyclotron (in Japanese)
Kurashima, Satoshi; Miyawaki, Nobumasa; Okumura, Susumu; Ishibori, Ikuo; Yoshida, Kenichi; Kashiwagi, Hirotsugu; Fukuda, Mitsuhiro; Nara, Takayuki; Agematsu, Takashi; Nakamura, Yoshiteru
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan , p.717-719(2005) ; (JAERI-J 22155)
 
330895
Book on the nuclear fusion energy in thoroughly plain words (in Japanese)
Inoue, Nobuyuki*; Yoshino, Ryuji
Tokoton Yasashi Kakuyugo Enerugi No Hon , p.1-159(2005) ; (JAERI-J 22156)
 This book gives an outline on the Nuclear Fusion Energy in plain words. This book shows that the nuclear fusion is an ultimate energy source, a core of the nuclear fusion energy plant is a high temperature plasma, and the tokamak machine has opened up a road to realize the nuclear fusion reactor. Furthermore the development progress of ITER project with Japanese big contribution on it and several characteristics of the Nuclear Fusion Energy are explained in this book.
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