JAEA Abstracts

-Research results below have been sorted by order of journals name.

-Sorry, some research results below have no English abstract.

June 2006

34000548
In situ monitoring of internal strain and height of InAs nanoislands grown on GaAs(001)
Takahashi, Masamitsu; Kaizu, Toshiyuki; Mizuki, Junichiro
Applied Physics Letters 88(10), p.101917_1-101917_3(2006) ; (JAEA-J 00671)

A monitoring technique for molecular beam epitaxial growth of InAs/GaAs(001) nanoislands is presented. With the help of synchrotron radiation, X-ray diffraction intensity mapping in reciprocal space has been measured during growth. The internal strain distribution and height of the Stranski-Krastanov islands were monitored at a temporal resolution of 9.6 s. The relaxation process of internal strain inside the Stranski-Krastanov islands displayed significant dependence on the growth temperature.

34000549
Improved density functional calculations including magnetic effects for RfCl₄ and its homologues
Anton, J.*; Hirata, Masaru; Fricke, B.*; Pershina, V.*
Chemical Physics Letters 380(1-2), p.95-98(2003) ; (JAEA-J 00672)

We use the newly developed non collinear spin polarized density functional method to describe the tetrachlorides of element Rutherfordium (Rf) and its homologues. It is the first time that a real three-dimensional molecule is described with this method. Without any additional corrections (used so far for the atomic values) we get nearly complete agreement for all homologues and thus a good prediction for the unknown value for RfCl₄.

34000550
Solvent extraction of lanthanides into an ionic liquid containing N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine
Shimojo, Kojiro; Naganawa, Hirochika; Kubota, Fukiko*; Goto, Masahiro*
Chemistry Letters 35(5), p.484-485(2006) ; (JAEA-J 00673)

The extraction behavior of lanthanides from aqueous solutions into an ionic liquids (IL) was investigated with N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) as a ligand. The extraction performance of TPEN for lanthanides is greatly enhanced by dissolution in IL compared to in chloroform. Furthermore, the stripping of lanthanides from IL into a receiving phase is successfully achieved under acidic conditions.

34000551
An Inference method of team situation awareness based on mutual awareness
Shu, Y.; Furuta, Kazuo*
Cognition, Technology & Work 7(4), p.272-287(2005) ; (JAEA-J 00674)

Team Situation Awareness (TSA) is a critical contributing factor in establishing collaborative relations among team members involved in cooperative activity. Currently, however, there is still a lack of a clearly understandable and commonly agreeable model of TSA. To resolve misunderstanding or conflict among team members or between a team and machines, our research aim is to find out the underlying mechanism of TSA that reflects team cognitive process in a way consistent with team cooperative activity, and to focus on how to achieve mutual understanding, and how to effectively incorporate human teams into a socio-technological system. In this paper, we argue that earlier models of TSA, where TSA was discussed as the intersection of situation awareness (SA) owned by individual team members, are inadequate for study of a sophisticated team reciprocal process. We suggest that it is necessary for the definition of TSA to integrate the notion of individual SA into cooperative team activity. In particular, understanding of mutual awareness is an essential element in cooperative activity. We propose a new notion of TSA, which is reducible to mutual beliefs as well as individual SA at three levels. Further, we develop an operational TSA inference method and discuss human competence and system-related factors that are required to build TSA. We then try to demonstrate how TSA is actively constructed via inferencing practices. We also develop criteria to assess appropriateness of TSA from two aspects: soundness and completeness of mutual beliefs. Comparison of evaluation results indicates that the notion of TSA proposed in this work is more suitable to depict team cooperative activity than conventional ones.

34000552
Electrochemical transient techniques for determination of uranium and rare-earth metal separation coefficients in molten salts
Kuznetsov, S. A.*; Hayashi, Hirokazu; Minato, Kazuo; Gaune-Escard, M.*
Electrochimica Acta 51(13), p.2463-2470(2006) ; (JAEA-J 00675)

Electrochemical experiments were carried out at 723-823K in order to estimate separation coefficients in LiCl-KCl eutectic melt containing uranium and lanthanum trichlorides. The diffusion coefficients of U(III) were determined by electrochemical methods. The standard rate constants of charge transfer for electroreduction of uranium U(III) +3e^-=U were calculated by the impedance spectroscopy method. It was shown that for the calculation of uranium and lanthanum separation coefficients it is necessary to determine the voltammetric peak potentials of U(III) and La(III), their concentration in the melt and the kinetic parameters relating to U(III) discharge such as transfer and diffusion coefficients, and standard rate constants of charge transfer.

34000553
Internal promoter characterization and expression of the Deinococcus radiodurans pprI-folP gene cluster
Gao, G.*; Le, D.*; Huang, L.*; Lu, H.*; Narumi, Issei; Hua, Y.*
FEMS Microbiology Letters 257(2), p.195-201(2006) ; (JAEA-J 00676)

PprI is a general gene switch responsible for the extraordinary radioresistance of Deinococcus radiodurans. From NCBI DNA sequence analysis, it was predicted that the translation start codon of the downstream folP gene overlaps the pprI stop codon, suggesting that these genes may form an operon. In this study, we show that a mutant containing an inserted sequence in folP does not grow unless folate is added to the medium, but is not affected in extreme radioresistance, whereasa pprI disruptant strain could grow in absence of folate. We now characterize the promoter of pprI by primer extension experiments. We show that expression of a pprI-lacZ fusion is constitutive and unaltered following ionizing radiation as is the production of the PprI protein. PprI protein is not expressed if its promoter is deleted and the transcription from the entire pprI promoter (containing a large region upstream of pprI gene) is essential for radioresistance of D. radiodurans. However, the deletion of pprI promoter has no effect on the expression of the folP-lacZ fusion. Primer extension analysis of the folP promoter region shows that folP is transcribed from its own promoter located within the pprI structural gene. All these results do neither support the existence of a pprI-folP operon nor a regulatory role of FolP in pprI expression.

34000554
Development and contribution of RF heating and current drive systems to long pulse, high performance experiments in JT-60U
Moriyama, Shinichi; Seki, Masami; Terakado, Masayuki; Shimono, Mitsugu; Ide, Shunsuke; Isayama, Akihiko; Suzuki, Takahiro; Fujii, Tsuneyuki; JT-60 Team
Fusion Engineering and Design 74(1-4), p.343-349(2005) ; (JAEA-J 00677)

34000555
Dynamical pressure anisotropy in liquid-gas model of lattice-gas
Ebihara, Kenichi
International Journal of Modern Physics C 17(1), p.53-64(2006) ; (JAEA-J 00678)

A liquid-gas model of lattice-gas is made by adding long-range interaction to lattice-gas and can simulate phase separation similar to that in the van der Waals' liquid-gas theory. This liquid-gas model can generate a circular dense-phase in the rare phase. In this paper, I simulate the deformation of the circular dense-phase by external force using the two types of liquid-gas models of lattice-gas, which are distinguished by the type of long-range interaction. It is observed in the simulation results that one type of model shows the valid deformation and the other shows the unphysical deformation. Futhermore it is found by numerical experiments that this difference of the deformation is caused by dynamical pressure anisotropy of the liquid-gas model of lattice-gas.

34000556
Interaction of Eu(III) ion and non-porous silica; Irreversible sorption of Eu(III) on silica and hydrolysis of silica promoted by Eu(III)
Takahashi, Yoshio*; Murata, Miho*; Kimura, Takaumi
Journal of Alloys and Compounds 408-412, p.1246-1251(2006) ; (JAEA-J 00679)

34000557
Curium(III) species and the coordination states in concentrated LiCl-aqueous solutions studied by time-resolved laser-induced fluorescence spectroscopy
Arisaka, Makoto; Kimura, Takaumi; Nagaishi, Ryuji; Yoshida, Zenko
Journal of Alloys and Compounds 408-412, p.1307-1311(2006) ; (JAEA-J 00680)

34000558
Characterization of a monofunctional catalase KatA from radioresistant bacterium Deinococcus radiodurans
Kobayashi, Issei*; Tamura, Takashi*; Sghaier, H.; Narumi, Issei; Yamaguchi, Shotaro*; Umeda, Koichi*; Inagaki, Kenji*
Journal of Bioscience and Bioengineering 101(4), p.315-321(2006) ; (JAEA-J 00681)

Catalase plays a key role in protecting cells against toxic reactive oxygen species. Here we report on the cloning, purification and characterization of a catalase (KatA) from the extremely radioresistant bacterium Deinococcus radiodurans. The size of purified D. radiodurans KatA monomer was 65 kDa while gel filtration revealed that the size of the enzyme was 240 kDa, suggesting that KatA formed a homotetramer in solution. Purified KatA displayed a final specific activity of 68,800 U/mg of protein. The catalase activity of KatA was inhibited by sodium azide, sodium cyanide and 3-amino-1, 2, 4-triazole. The absorption spectrum of KatA exhibited a Soret band at 408 nm. The position of the spectral peak remained unchanged following reduction of KatA with dithionite. No peroxidase activity was found for KatA. These results demonstrate that D. radiodurans KatA is a typical monofunctional heme-containing catalase. The stability of KatA with respect to H₂O₂ stress was superior to that of commercially available Aspergillus niger and bovine liver catalases. The relative abundance of KatA in cells in addition to the H₂O₂ resistance property may play a role in the survival strategy of D. radiodurans against oxidative damage.

34000559
Pressure dependence of local structure in liquid carbon disulfide
Yamamoto, Sekika*; Ishibashi, Yasuhiko*; Inamura, Yasuhiro; Katayama, Yoshinori; Mishina, Tomobumi*; Nakahara, Junichiro*
Journal of Chemical Physics 124(14), p.144511_1-144511_5(2006) ; (JAEA-J 00682)

High pressure X-ray diffraction measurements on liquid carbon disulfide up to 1.2 GPa are performed by using an energy dispersion method. The results are compared with a molecular dynamics calculation with usual Lennard-Jones potential. They give very good agreement for all pressures measured. It becomes clear that the liquid structure changes like hard core liquid up to the pressure just below crystallizing point. The relation between structural change and optical response at high pressure is discussed.

34000560
Theoretical study on the alloying behavior of γ-uranium metal; γ-uranium alloy with 3d transition metals
Kurihara, Masayoshi*; Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*
Journal of Nuclear Materials 326(2-3), p.75-79(2004) ; (JAEA-J 00683)

We have investigated the alloying behavior of g-uranium with 3d transition metals (TMs) using the relativistic discrete-variational Dirac-Fock-Slater (DV-DFS) method. The d-orbital energy (Md) as an alloying parameter well reproduces the alloying behavior of g- uranium metal with TMs: (1) in the case of a large Md value (Ti,V,Cr), the solubility of these TM elements in g-uranium becomes large; (2) in the case of a middle Md value (Mn,Fe,Co), the tendency to form a uranium intermetallic compound with these elements becomes stronger; (3) in the case of a small Md value (Cu), the alloying element is insoluble in g-uranium. The alloying behavior of g-uranium with TMs is also discussed in terms of other parameters such as electronegativity and metallic radius.

34000561
Assessment of human body surface and internal dose estimations in criticality accidents based on experimental and computational simulations
Sono, Hiroki; Ono, Akio*; Kojima, Takuji; Takahashi, Fumiaki; Yamane, Yoshihiro*
Journal of Nuclear Science and Technology 43(3), p.276-284(2006) ; (JAEA-J 00684)

For a study on the applicability of a personal dosimetry method to criticality accident dosimetry, an assessment of the human body surface and internal dose estimations was performed by experimental and computational simulations. The experimental simulation was carried out in a criticality accident situation at the TRACY facility. The neutron and γ-ray absorbed doses in muscle tissue were separately estimated by a dosimeter set of an alanine dosimeter and a thermoluminescence dosimeter made of enriched lithium tetra borate with a phantom. The computational simulation was conducted with a Monte Carlo code taking account of dose components of neutrons, prompt γ-rays and delayed γ-rays. The computational simulation was ascertained to be valid by comparison between the calculated dose distributions in the phantom and the measured ones. The assessment based on the experimental and computational simulations confirmed that the personal dosimetry using the dosimeter set provided a first estimation of the body surface and internal doses with precision.

34000562
Operation scenarios and requirements for fuel processing in future fusion reactor facilities; Hydrogen isotope separation as a key process for fuel recycle and safety
Ohira, Shigeru; Yamanishi, Toshihiko; Hayashi, Takumi
Journal of Nuclear Science and Technology 43(4), p.354-360(2006) ; (JAEA-J 00685)

In this paper, expected operation scenarios for ITER and future fusion reactors from a viewpoint of an integrated isotope processing in a future D-T fusion rector are provided with comparisons of requirements for system design attributed to the operation scenarios, safety requirements, etc. Most of the basic requirements for fuel process of a D-T fusion reactor facility common are the same, but the design requirements coming from the individual operation scenarios of ITER and future demo reactors will differ. The system design requirements of the tritium plant taking care of various operations of ITER and a demo reactor are examined and compared. Due to the increase of tritium concentration in the coolant of a demo reactor by tritium permeation in the structural material of the in-vessel components operated at a temperature higher than that of ITER detritiation of coolant will be getting more important. Some important key parameters related to hydrogen isotope processing in future fusion reactors will be discussed.

34000563
Theoretical analysis of electronic structure for the chemical bonding of Pu and Am in MgO
Tanaka, Kumiko; Hirata, Masaru; Sekine, Rika*
Journal of Nuclear and Radiochemical Sciences 5(2), p.27-31(2004) ; (JAEA-J 00686)

The relativistic discrete-variational Dirac-Fock-Slater (DV-DFS) method was performed to investigate the electronic structure of MgO doped with Pu or Am atoms. The differences between these systems, in particular, the participation of d-electrons and f-electrons in chemical bonding, were clarified by calculating their electronic structures. Substitution of actinide atoms was found to result in the effective charges of MgO becoming smaller, with a large charge transfer occurring as far as the second layer. It was also found that the bonding feature between the center atom and the surrounding oxygen atoms was extended to lower energy in the case of actinide (An) substituted systems. Moreover, the bonding characteristics were assigned; a bonding interaction for An6d-O2p and an anti-bonding for An5f-O2p near the HOMO level. These complex effects were found to dominate the strength of the covalent bonding between MgO and actinide atoms.

34000564
Operational progress of the 110GHz-4MW ECRF heating system in JT-60U
Fujii, Tsuneyuki; Seki, Masami; Moriyama, Shinichi; Terakado, Masayuki; Shinozaki, Shinichi; Hiranai, Shinichi; Shimono, Mitsugu; Hasegawa, Koichi; Yokokura, Kenji; JT-60 Team
Journal of Physics: Conference Series 25, p.45-50(2005) ; (JAEA-J 00687)

The JT-60U electron cyclotron range of frequency (ECRF) is utilized to realize high performance plasma. Its output power is 4 MW at 110 GHz. By controlling the anode voltage of the gyrotron used in the JT-60U ECRF heating system, the gyrotoron output can be controlled. Then, the anode voltage controller was developed to modulate the injected power into plasmas. This low cost controller achieved the modulation frequency 12 - 500 Hz at 0.7 MW. This controller also extended the pulse width from 5s to 16 s at 0.5 MW. For these long pulses, temperature rise of the DC break made of Alumina ceramics is estimated. Its maximum temperature becomes ~ 140 deg. From the analysis of this temperature rise, DC break materials should be changed to low loss materials for the objective pulse width of 30 s. The stabilization of neoclassical tearing mode (NTM) was demonstrated by ECRF heating using the real-time system in which the ECRF beams are injected to the NTM location predicted from ECE measurement every 10 ms.

34000565
Coupled electron and atomic kinetics through the solution of the Boltzmann equation for generating time-dependent X-ray spectra
Sherrill, M. E.*; Abdallah Jr., J.*; Csanak, G.*; Kilcrease, D. P.*; Dodd, E. S.*; Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Yamakawa, Koichi; Faenov, A. Y.*; Magunov, A. I.*; Pikuz, T. A.*; Skobelev, I. Y.*
Journal of Quantitative Spectroscopy & Radiative Transfer 99(1-3), p.584-594(2006) ; (JAEA-J 00688)

In this work, we present a model that solves self-consistently the electron and atomic kinetics to characterize highly non-equilibrium plasmas, in particular for those systems where both the electron distribution function is far from Maxwellian and the evolution of the ion level populations are dominated by time dependent atomic kinetics. In this model, level populations are obtained from a detailed collisional-radiative model where collision rates are computed from a time varying electron distribution function obtained from the solution of the zero-dimensional Boltzmann equation. The Boltzmann collision term includes the effects of electron-electron collisions, electron collisional ionization, excitation and de-excitation. An application for He_α spectra from a short pulse laser irradiated argon cluster target will be shown to illustrate the results of our model.

34000566
X-ray photoelectron spectroscopic observation on B-C-N hybrids synthersized by ion beam deposition of borazine
Uddin, M. N.; Shimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro; Nagano, Masamitsu*
Journal of Vacuum Science and Technology A 23(3), p.497-502(2005) ; (JAEA-J 00689)

B-C-N hybrid thin films were grown from ion beam plasma of borazine (B₃N₃H₆) on graphite substrate at room temperature, 600^°C, and 850^°C. The films were characterized by X-ray photoelectron spectroscopy (XPS). XPS study suggested that B and N atoms in the deposited films are in a wide variety of chemical bonds e.g., B-C, B-N, N-C, and B-C-N. The substrate temperature and ion fluence were shown to have significant effect on the coordination and elemental binding states on the B-C-N hybrids. It was found that B-C-N hybrid formation is enhanced at high temperature, and this component is dominantly synthesized at low fluence. The results imply that it is possible to control the composition of B-C-N hybrid by changing the ion fluence and the temperature during ion implantation.

34000567
Soft X-ray absorption magnetic circular dichroism study of ferromagnetic superconductor UGe₂
Okane, Tetsuo; Okamoto, Jun*; Mamiya, Kazutoshi*; Fujimori, Shinichi; Takeda, Yukiharu; Saito, Yuji; Muramatsu, Yasuji*; Fujimori, Atsushi*; Haga, Yoshinori; Yamamoto, Etsuji; Tanaka, Arata*; Homma, Tetsuo*; Inada, Yoshihiko*; Onuki, Yoshichika*
Journal of the Physical Society of Japan 75(2), p.024704_1-024704_5(2006) ; (JAEA-J 00690)

34000568
Rattling of Pr in heavy-fermion superconductor PrOs₄Sb₁₂ revealed by neutron powder diffraction
Kaneko, Koji; Metoki, Naoto; Matsuda, Tatsuma; Kogi, Masafumi*
Journal of the Physical Society of Japan 75(3), p.034701_1-034701_5(2006) ; (JAEA-J 00691)

Neutron powder diffraction experiments were carried out on the heavy-fermion superconductor PrOs₄Sb₁₂ down to 7.7,K in order to reveal the thermal displacement of Pr and investigate the possible existence of off-center potential minima for Pr in the Sb cage. Rietveld analysis with the structure in which Pr is located at the center of the Sb cage well reproduces the observed patterns. A large thermal displacement was obtained for Pr of U_Pr=0.0344Å² at 295.1K, roughly corresponding to a mean thermal displacement of 0.18Å. This value is 5 times larger than those of other constituents, U_Os and U_Sb. U_Pr remains large, U_Pr,=0.0062Å², even at 7.7K, which is twice as large as U_Os and U_Sb. Neither structural transition nor significant change of the Sb cage accompanied this change in U_Pr. The large U_Pr and its strong temperature dependence indicate the rattling of Pr under a shallow potential in the Sb cage. An equal distribution of Pr at 12e sites (x,0,0) was introduced to approximate the off-center potential minima. The R factors were not improved by the introduction of the off-center site.

34000569
Ground-state band of the neutron-rich transuranium nucleus ²⁵⁰Cm₁₅₄
Ishii, Tetsuro; Shigematsu, Soichiro; Makii, Hiroyuki; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Matsuda, Makoto; Makishima, Akiyasu*; Shizuma, Toshiyuki; Kaneko, Junichi*; Hossain, I.*; Tome, Hayato*; Ohara, Masako*; Ichikawa, Shinichi; Kono, Toshiyuki*; Ogawa, Masao*
Journal of the Physical Society of Japan 75(4), p.043201_1-043201_4(2006) ; (JAEA-J 00692)

The ground-state band of the neutron-rich transuranium nucleus ²⁵⁰Cm was established up to spin 12 by in-beam γ-ray spectroscopy using the two-neutron-transfer reaction with a ²⁴⁸Cm target and a 162 MeV ¹⁸O beam. Deexcitation γ rays in ²⁵⁰Cm were identified by selecting the kinetic energies of ¹⁶O particles with Si Δ E-E detectors. The moment of inertia of ²⁵⁰Cm₁₅₄ is considerably smaller than that of ²⁴⁸Cm₁₅₂, which supports the existence of the deformed subshell closure at N=152 in Cm isotopes.

34000570
Chemical modification of the internal surfaces of cylindrical pores of submicrometer size in poly(ethylene terephthalate)
Maekawa, Yasunari; Suzuki, Yasuyuki; Maeyama, Katsuya*; Yonezawa, Noriyuki*; Yoshida, Masaru
Langmuir 22(6), p.2832-2837(2006) ; (JAEA-J 00693)

Chemical modification of the internal surfaces of cylindrical pores with sub-micrometer of pore diameter in PET film was examined. The modification involved the alkylation of the carboxylic acid on the surfaces with the alkylation reagent containing a fluorescent probe, and it was monitored by observing the change in fluorescent emission intensity. When the DMF solution of 4-(bromomethyl)-6,7-dimethoxycoumarin (BrCU), which bore a coumarin fluorophore, was introduced into the pores, the emission and excitation intensities of the membranes increased proportionally with increases of the pore surface areas. Fluorescent spots of about 300 nm in diameter, which were located at the positions of the pores, can be observed in the fluorescence microscope image of the membranes, indicating that highly concentrated fluorescent probes are chemically incorporated on the internal surfaces of the cylindrical pores with 210 nm in diameter in the membranes. In the reactions of the PET surfaces with BrCU, the fluorescent intensities increased with increases of the contact angles. This result indicates that the hydrophilicity of the internal pore surfaces can be qualitatively modified by controlling the change in the fluorescent intensities.

34000571
X-ray emission from multi-inner-shell excited states produced by high-intensity short-pulse X-rays
Moribayashi, Kengo; Lee, K.*; Kagawa, Takashi*; Kim, D. E.*
Laser Physics 16(2), p.322-324(2006) ; (JAEA-J 00694)

34000572
Method for detecting DNA strand breaks in mammalian cells using the Deinococcus radiodurans PprA protein
Sato, Katsuya*; Wada, Seiichi; Kikuchi, Masahiro; Funayama, Tomoo; Narumi, Issei; Kobayashi, Yasuhiko
Mutation Research; Fundamental and Molecular Mechanisms of Mutagenesis 596(1-2), p.36-42(2006) ; (JAEA-J 00695)

In a previous study we identified the novel protein PprA that plays a critical role in the radiation resistance of Deinococcus radiodurans. In this study, we focussed on the ability of PprA protein to recognize and bind to double-stranded DNA carrying strand breaks, and attempted to visualize radiation-induced DNA strand breaks in mammalian cultured cells by employing PprA protein using an immunofluorescence technique. Increased PprA protein binding to CHO-K1 nuclei immediately following irradiation suggests the protein is binding to DNA strand breaks. By altering the cell permeabilization conditions, PprA protein binding to CHO-K1 mitochondria, which is probably resulted from DNA strand break immediately following irradiation, was also detected. The method developed and detailed in this study will be useful in evaluating DNA damage responses in cultured cells, and could also be applicable to genotoxic tests in the environmental and pharmaceutical fields.

34000573
Electron cyclotron heating assisted startup in JT-60U
Kajiwara, Ken*; Ikeda, Yoshitaka; Seki, Masami; Moriyama, Shinichi; Oikawa, Toshihiro; Fujii, Tsuneyuki; JT-60 Team
Nuclear Fusion 45(7), p.694-705(2005) ; (JAEA-J 00696)

Electron cyclotron heating (ECH) assisted start-up experiment was performed in JT-60U. The breakdown loop voltage, becoming the maximum value at the plasma start-up, successfully reduced from 30 V to 4 V (E = 0.26 V/m) by 200 kW ECH. This fulfills the value less than 0.3 V/m, which corresponds to the maximum electric field required in ITER. Moreover, in order to investigate properties of start-up plasmas, parameter scans of the ECH power, prefilled gas pressure, resonant position, polarization angle and injection position were carried out and the dependence on them were obtained. It was revealed that the properties have dependences on the injection position and polarization angle in large tokamaks although they seemed to have no dependence on them from the experiments in small and medium tokamaks. In addition, in experiments of the plasma start-up using second and third harmonic ECH, it was found that the plasma current was ramped by 800 kW second harmonic ECH and was not ramped by 1.6 MW third harmonic ECH even with 7 MW neutral beam injection heating.

34000574
Observation of ion-irradiation induced diffusion in Pd-Si system using synchrotron radiation X-ray photoelectron spectroscopy
Iwase, Akihiro*; Chimi, Yasuhiro; Ishikawa, Norito; Nakatani, Rikizo*; Kato, Yuzaburo*; Fukuzumi, Masafumi*; Tsuchida, Hidetsugu*; Baba, Yuji
Nuclear Instruments and Methods in Physics Research B 245(1), p.141-144(2006) ; (JAEA-J 00697)

Diffusion of Si atoms in Pd under energetic ion irradiation is studied in Pd-Si thin layer system using synchrotron radiation photoemission spectroscopy. Specimens are prepared by depositing Pd on Si single crystals. The Pd layer thicknesses are 10-300 nm. Before irradiation, we observe photoemission spectra only for Pd, but do not find any trace of Si. After irradiation with 3-MeV Si ions, 1-MeV O ions or 200-MeV Xe ions, we observe an additional photoemission component at the binding energy about 3 eV higher than that of Si 1s bulk component. The experimental result implies that the energetic ion-irradiation induces the diffusion of Si atoms from the Si-Pd interface to the Pd layer surface. The shift of the binding energy from the value for the Si bulk can be interpreted as arising from electron charge transfer from Si to Pd. The dependences of photoemission spectra and ion-irradiation induced diffusion on ion-species and ion-fluence are discussed.

34000575
Effects of swift heavy ion irradiation on magnetic properties of Fe-Rh alloy
Fukuzumi, Masafumi*; Chimi, Yasuhiro; Ishikawa, Norito; Suzuki, Motohiro*; Takagaki, Masafumi*; Mizuki, Junichiro; Ono, Fumihisa*; Neumann, R.*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B 245(1), p.161-165(2006) ; (JAEA-J 00698)

We have performed swift heavy ion irradiations in Fe-50at.%Rh alloys at room temperature. Before and after the irradiations, the magnetic properties and the lattice structure are measured using Superconducting QUantum Interference Device (SQUID) and X-Ray Diffractometer (XRD), respectively. We have also performed X-ray Magnetic Circular Dichroism (XMCD) measurement near the Fe K-edge at the synchrotron radiation facility, SPring-8, to examine the irradiation-induced ferromagnetic state near the specimen surface. We have found that the swift heavy ion irradiations induce the ferromagnetic state in Fe-50at.%Rh alloy below the antiferromagnetism-ferromagnetism transition temperature of the unirradiated alloy and the lattice expasion by 0.3%. For the specimens irradiated with swift heavy ions, we observe the XMCD spectra correponding to ferromagnetisim, which depend on the mass of irradiating ions and/or irradiation fluence. Effects of energy loss through electronic excitation and elastic collisions on lattice and magnetic structures of Fe-Rh alloy are discussed.

34000576
Effect of high-energy ion irradiation on magnetic properties in Fe-Pt invar alloys
Ono, Fumihisa*; Kanamitsu, Hiroaki*; Matsushima, Yasushi*; Chimi, Yasuhiro; Ishikawa, Norito; Kambara, Tadashi*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B 245(1), p.166-170(2006) ; (JAEA-J 00699)

Specimens of both ordered and disordered Fe-28.3at.%Pt alloys were irradiated with 200-MeV Xe ions to the fluence of 10¹⁴ ions/cm². Measurements of AC-susceptibility-temperature curves were made for each specimen before and after the irradiation by using a specially designed apparatus for rapid measurements. In contrast to the expectation from the previous results for Fe-Ni alloys, in disordered Fe-Pt invar alloy the Curie temperature, T_C decreased about 15 K by the irradiation. This fact cannot be explained by considering the lattice expansion effect alone. In Fe-Pt invar alloys the effect of lattice expansion may be cancelled out by some other effects which may be originated from the large difference in atomic mass between the two elements. For ordered Fe-Pt alloy, T_C decreased as large as 60 K with the same fluence. The value of T_C for both ordered and disordered Fe-Pt invar alloys coincide with each other after the irradiation. This fact can be explained by considering that the ordered state becomes disordered by the irradiation.

34000577
Swift heavy ion irradiation effects in nanocrystalline gold
Chimi, Yasuhiro; Iwase, Akihiro*; Ishikawa, Norito; Kobiyama, Mamoru*; Inami, Takashi*; Kambara, Tadashi*; Okuda, Shigeo*
Nuclear Instruments and Methods in Physics Research B 245(1), p.171-175(2006) ; (JAEA-J 00700)

We have studied effects of irradiation with energetic particles on defect accumulation in nanocrystalline gold (nano-Au). The specimens of nano-Au foil (3-5 μm thickness) with various grain sizes (23-156 nm) are prepared by the gas deposition method and subsequent thermal annealings. Irradiations of the specimens with 60-MeV ¹²C ions, 3.54-GeV ¹³⁶Xe ions or 2.0-MeV electrons are performed at low temperature. The defect accumulation behavior is observed by measuring the electrical resistivity change during irradiation. Through an analysis of defect accumulation behavior, cross-sections for defect production, σ_d, and annihilation, σ_r, in nano-Au increase monotonically as the grain size decreases. These results are considered to be caused by the existence of a large volume fraction of the regions near grain boundaries in nano-Au where the threshold energy for atomic displacements, E_d, becomes lower than in polycrystalline gold. The possibility of electronic excitation effects in nano-Au is also discussed.

34000578
Microstructure and atomic disordering of magnesium aluminate spinel irradiated with swift heavy ions
Yamamoto, Tomokazu*; Shimada, Mikio*; Yasuda, Kazuhiro*; Matsumura, Sho*; Chimi, Yasuhiro; Ishikawa, Norito
Nuclear Instruments and Methods in Physics Research B 245(1), p.235-238(2006) ; (JAEA-J 00701)

We have investigated the microstructure change and atomic disordering process in magnesium aluminate spinel, MgO nAl₂O₃ with n=1.1 and 2.4, irradiated with swift heavy ions of 200-MeV Xe¹⁴⁺ and 350-MeV Au²⁸⁺. Transmission electron microscopy techniques of bright-field (BF) and high-resolution (HR) imaging, as well as high angular resolution electron channeling X-ray spectroscopy (HARECXS) are employed in quantitative analysis of irradiation-induced structural change. Ion tracks show columnar dark contrast of 4-7 nm in diameter at the incident surface in BF images. Strong strain contrast often arises among plural ion tracks formed closely. Clear lattice fringes are observed in HR images even inside the ion tracks. It indicates that the spinel crystals are not amorphized but partially disordered along the ion tracks. Quantitative HARECXS analysis shows that cation disordering progresses with ion fluence. It is revealed that the disordered regions are extended over 12±2 nm in diameter along the ion tracks.

34000579
Influence of uranium enrichment on the etching rate of polycarbonate fission track detector containing uranium particles
Lee, C. G.; Iguchi, Kazunari; Esaka, Fumitaka; Magara, Masaaki; Sakurai, Satoshi; Watanabe, Kazuo; Usuda, Shigekazu
Nuclear Instruments and Methods in Physics Research B 245(2), p.440-444(2006) ; (JAEA-J 00702)

The etching rates of fission track detectors made of polycarbonate containing uranium particles were measured after thermal neutron irradiation with fluence of 8×10¹⁴ n/cm², in order to study the influence of uranium enrichment on the etching rate that was calculated from the weight loss by etching. There is a strong correlation between the etching rate of detector and the enrichment E of uranium particle: the former increases as the latter increases. Particularly, the etching rate per particle was proportional to E^2/3 rather than E¹, which is probably due to the overlapping of fission tracks. The etching behaviors of detector revealed that the existence of two different etching rate regions, a nonlinear region in the beginning of etching process and a subsequent constant region, which was explained as the opening of fission tracks and the broadening of opened tracks, respectively.

34000580
Positron study of electron irradiation-induced vacancy defects in SiC
Kawasuso, Atsuo; Yoshikawa, Masahito; Ito, Hisayoshi; Krause-Rehberg, R.*; Redmann, F.*; Higuchi, Takatoshi*; Betsuyaku, Kiyoshi*
Physica B; Condensed Matter 376-377, p.350-353(2006) ; (JAEA-J 00703)

In this presentation, we report identification of vacancy defects in cubic and hexagonal SiC irradiated with fast electrons through electron-pisitron momentum distribution measurements and theoretical analyses. In cubic SiC isolated silicon vacancies are responsible for positron trapping. The lifetime of positrons trapped at silicon vacancies is prolonged due to the outward lattice relaxation. Because of the local tetrahedral symmetry of silicon vacancies, the observed momentum distributions are consistently explained. In the case of hexagonal SiC, one particular vacancy defects appearing after annealing of isolated silicon vacancies have dangling bonds along the c-axis. From the enhancement of positron annihilation probability with carbon 1s electrons, the above defects are attributed to carbon-vacancy-antisite-carbon complexes.

34000581
Defect layer in SiO₂-SiC interface proved by a slow positron beam
Maekawa, Masaki; Kawasuso, Atsuo; Yoshikawa, Masahito; Miyashita, Atsumi; Suzuki, Ryoichi*; Odaira, Toshiyuki*
Physica B; Condensed Matter 376-377, p.354-357(2006) ; (JAEA-J 00704)

34000582
Direct numerical simulations for non-equilibrium superconducting dynamics and related neutron detection in MgB₂
Machida, Masahiko; Koyama, Tomio*; Kato, Masaru*; Ishida, Takekazu*
Physica C 426-431(1), p.169-173(2005) ; (JAEA-J 00705)

34000583
Josephson half-quantized vortices in long square π junctions around d-dot
Machida, Masahiko; Koyama, Tomio*; Kato, Masaru*; Ishida, Takekazu*
Physica C 426-431(2), p.1566-1571(2005) ; (JAEA-J 00706)

34000584
Molecular dynamics simulations of lanthanide(III) diphenyldimethylpyridinyl-dicarboxyamide complexes in water and in methanol; Evidence for both first and second sphere complexes
Dobler, M.; Hirata, Masaru
Physical Chemistry Chemical Physics 6(8), p.1672-1678(2004) ; (JAEA-J 00707)

34000585
Antiferromagnetic-to-ferromagnetic transition induced by diluted Co in SrFe_1-xCo_xO₃:Magnetic circular X-ray dichroism study
Okamoto, Jun*; Mamiya, Kazutoshi*; Fujimori, Shinichi; Okane, Tetsuo; Saito, Yuji; Muramatsu, Yasuji*; Yoshii, Kenji; Fujimori, Atsushi*; Tanaka, Arata*; Abbate, M.*; Koide, Tsuneharu*; Ishiwata, Shintaro*; Kawasaki, Shuji*; Takano, Mikio*
Physical Review B 71(10), p.104401_1-104401_5(2005) ; (JAEA-J 00708)

The antiferromagnetic-to-ferromagnetic transition in SrFe_1-xCo_xO₃ (x_c~0.15) induced by Co doping has been studied by magnetic circular X-ray dichroism. The orbital and spin magnetic moments of the Fe and Co 3d states under the magenetic field of 2 T are found to show different x dependences: The spin polarization of Fe 3d gradually increases with Co concentration; On the other hand, a large spin polarization of Co 3d is induced already in the antiferromagnetic phase, indicating that the Co moment is nearly fully alligned already in the antiferromagnetic phase. This suggests that the alignment of the Fe magnetic moment in SrFe_1-xCo_xO₃ is induced by interaction with doped Co magnetic moment. Possible formation of ferromagnetic Co rich region is discussed.

34000586
Ga NMR study of UGa₃; Antiferromagnetically ordered state
Kambe, Shinsaku; Walstedt, R. E.; Sakai, Hironori; Tokunaga, Yo; Matsuda, Tatsuma; Haga, Yoshinori; Onuki, Yoshichika
Physical Review B 72(18), p.184437_1-184437_8(2005) ; (JAEA-J 00709)

Temperature dependence of the spin-lattice relaxation time (T₁) at Ga site are measured for the paramagnetic and antiferromagnetically (AFM) ordered states of UGa₃(T_N=66K). Clear minimaum of T₁ has been observed at ~62K in addition to a minimun at T_N, indicating that second order phase transtion occures at both temperatures. Based on a comparison between T₁ of ⁶⁹Ga and ⁷¹Ga nucleai, the enhanced fluctuations at both temparature are magnetic. The origin of the transitions are discussed.

34000587
A Mutation in the uvi4 gene promotes progression of endo-reduplication and confers increased tolerance towards ultraviolet B light
Hase, Yoshihiro; Trung, K. H.*; Matsunaga, Tsukasa*; Tanaka, Atsushi
Plant Journal 46(2), p.317-326(2006) ; (JAEA-J 00711)

We have isolated and characterized a new ultraviolet-B (UV-B)-resistant mutant, uvi4, of Arabidopsis. The fresh weight of uvi4 plants grown under supplemental UV-B light was more than twice that of the wild type. No significant difference was found in the ability to repair the UV-B-induced cyclobutane pyrimidine dimers (CPDs), or in the amount of UV-B absorptive compounds, both of which are well known factors that contribute to UV sensitivity. Positional cloning revealed that the UVI4 gene encodes a novel basic protein of unknown function. We found that the hypocotyl cells in uvi4 undergo one extra round of endoreduplication. The uvi4 mutation also promoted the progression of endoreduplication during leaf development. The UVI4 gene is expressed mainly in actively dividing cells. In the leaves of PUVI4::GUS plants, the GUS signal disappeared in basipetal fashion as the leaf developed. The total leaf blade area was not different between uvi4 and the wild type through leaf development, while the average cell area in the adaxial epidermis was considerably larger in uvi4, suggesting that the uvi4 leaves have fewer but larger epidermal cells. These results suggest that the UVI4 is necessary for the maintenance of the mitotic state and the loss of UVI4 function stimulated endoreduplication. Tetraploid Arabidopsis was hyperresistant to UV-B compared to diploid Arabidopsis, suggesting that the enhanced polyploidization is responsible for the increased UV-B tolerance of the uvi4.

34000588
Physics of strong internal transport barriers in JT-60U reversed-magnetic-shear plasmas
Hayashi, Nobuhiko; Takizuka, Tomonori; Sakamoto, Yoshiteru; Fujita, Takaaki; Kamada, Yutaka; Ide, Shunsuke; Koide, Yoshihiko
Plasma Physics and Controlled Fusion 48(5A), p.A55-A61(2006) ; (JAEA-J 00712)

34000589
Long pulse operation of high performance plasmas in JT-60U
Ide, Shunsuke; JT-60 Team
Plasma Science and Technology 8(1), p.1-4(2006) ; (JAEA-J 00713)

Recent progress in development of high performance plasma and efforts to prolong their sustainment towards ITER advanced operations and a steady-state reactor in JT-60U are presented focusing following achievements; βN=3 sustained for 6.2s (~4.1tR) without NTMs in normal shear, fBS~0.45 sustained for 5.8s (~2.8tR) under nearly full CD in weak a shear plasma, fBS~0.75 sustained for 7.4s (2.7tR) under nearly full CD in a reversed shear plasma. Furthermore, importance of these results and issues in advanced tokamak development will be discussed.

34000590
Switch interactions control energy frustration and multiple flagellar filament structures
Kitao, Akio*; Yonekura, Koji*; Yonekura, Saori*; Samatey, F.*; Imada, Katsumi*; Namba, Keiichi*; Go, Nobuhiro
Proceedings of the National Academy of Sciences of the United States of America 103(13), p.4894-4899(2006) ; (JAEA-J 00714)

34000591
Compact antenna for two-dimensional beam scan in the JT-60U electron cyclotron heating/current drive system
Moriyama, Shinichi; Kajiwara, Ken*; Takahashi, Koji; Kasugai, Atsushi; Seki, Masami; Ikeda, Yoshitaka; Fujii, Tsuneyuki; JT-60 Team
Review of Scientific Instruments 76(11), p.113504_1-113504_6(2005) ; (JAEA-J 00715)

A compact antenna has been designed and fabricated to enable millimeter wave beam scan in the toroidal and the poloidal directions of the JT-60U Tokamak, for electron cyclotron heating (ECH) and current drive (ECCD) experiments. It consists of fast movable flat mirror mounted on the Tokamak vacuum vessel, and rotary focusing mirror attached at the end of the waveguide supported from outside of the vacuum vessel. This separate support concept enables compact structure in the shallow port (0.68 m × 0.54 m × 0.2m) sharing with a sub-port for an independent diagnostic system. The flat mirror is driven during a shot by a servo-motor with a 3 m long drive shaft to refuse influence of the high magnetic field to the motor. The focusing mirror is rotated by a simple mechanism with a push rod and an air cylinder. The antenna has been operated reliably for 3 years after small improvement in the rotary mechanism. It has been contributing ECH and ECCD experiments especially current profile control, in JT-60U.

34000592
Consumption kinetics of Si atoms during growth and decomposition of very thin oxide on Si(001) surfaces
Ogawa, Shuichi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; Teraoka, Yuden; Takakuwa, Yuji*
Thin Solid Films 508(1-2), p.169-174(2006) ; (JAEA-J 00716)

The surface morphological change during growth and subsequent decomposition of very thin oxide on Si(001) surface was observed in real time by RHEED combined with AES and macroscopically by STM. The RHEED intensity ratio between half-order spots revealed that etching of the surface took place in a manner of nucleation and lateral growth of dimer vacancy on the terrace during two-dimensional (2D) oxide island growth at 690^°C, whereas the resultant oxide layer was decomposed at 709^°C with consumption of Si atom in a step flow mode. STM observation of the partially oxide decomposed surface, however, showed that a number of Si islands with 10-20 angstrom in diameter remained randomly over the rather atomically flat terraces within voids in spite of the step-flow etching. These results are considered in terms of the phase separation of Si-rich oxide grown by 2D oxide island growth mode between Si clusters and a stoichiometric SiO₂ matrix and subsequent precipitation of Si islands on the terrace during decomposition.

34000593
Hybrid coarse-grained-particle/molecular-dynamics simulation method for nano-device analyses (in Japanese)
Igarashi, Takahiro; Ogata, Shuji*
Bussei Kenkyu 86(1), p.1-36(2006) ; (JAEA-J 00717)

34000594
Radioactive waste management in O-arai Research and Development Center (in Japanese)
Maeda, Atsushi; Kowata, Koichi; Yamazaki, Yasuo; Takahashi, Kozo; Okubo, Toshiyuki; Miyazaki, Hitoshi
Dekomisshoningu Giho (33), p.58-66(2006) ; (JAEA-J 00718)

By the Japan Atomic Energy Agency (JAEA), designed decommissioning of nuclear facility and the treatment and disposal of radioactive waste will be carried out systematically and efficiently as responsibility as the installer of the nuclear power facility and generator of radioactive waste. This paper shows the present status of radioactive waste management in O-arai Research and Development Center, one of the research and development bases of JAEA. The management of low-level radioactive waste, including those accepted from outside operator of O-arai district, is carried out by the major premise of ensuring safety at O-arai Waste Management Facility. Treatment related to volume reduction and stabilization by means such as incineration and compression of solid waste, and solidification of liquid, as well as waste storage management is steadfastly promoted, so that these substances may be adequately stored and managed until they are disposed of.

34000595
Current status of food irradiation in the world (in Japanese)
Kume, Tamikazu
Enerugi Rebyu 26(5), p.23-26(2006) ; (JAEA-J 00719)

34000596
Development of polymer electrolyte membranes for fuel cell applications; Radiation processing technology offers solutions to energy and environmental problems (in Japanese)
Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
Isotope News (623), p.2-7(2006) ; (JAEA-J 00721)

34000597
The Requirements and R&D status for accelerator used in ADS (Accelerator-Driven transmutation System) (in Japanese)
Mizumoto, Motoharu
Kasokuki 3(1), p.74-92(2006) ; (JAEA-J 00723)

34000598
Development of fluoropolymer electrolyte membranes for fuel cell applications by the γ-ray induced crosslinking and graft polymerization methods (in Japanese)
Sawada, Shinichi; Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
Kobunshi Rombunshu 63(3), p.149-159(2006) ; (JAEA-J 00724)

34000599
Improvement of core dynamics analysis of control rod withdrawal test in HTGR (in Japanese)
Takamatsu, Kuniyoshi; Nakagawa, Shigeaki
Nippon Genshiryoku Gakkai Wabun Rombunshi 5(1), p.45-56(2006) ; (JAEA-J 00725)

The HTTR (High Temperature Engineering Test Reactor), which has thermal output of 30MW, coolant inlet temperature of 395^°C and coolant outlet temperature of 850^°C/950^°C, is a first high temperature gas-cooled reactor (HTGR) in Japan. The HTGR has a high inherent safety potential to accident condition. Safety demonstration tests using the HTTR are underway in order to demonstrate such excellent inherent safety features of the HTGR. A one-point core dynamics approximation with one fuel channel model had applied to this analysis. It was found that the analytical model for core dynamics couldn't simulate the reactor power behavior accurately. This report proposes an original method using temperature coefficients of some regions in the core. It is crucial to evaluate this method precisely to simulate a performance of HTGR during the test.

34000600
Evaluation of fuel temperature on high temperature test operation at high temperature gas-cooled reactor 'HTTR' (in Japanese)
Tochio, Daisuke; Sumita, Junya; Takada, Eiji*; Fujimoto, Nozomu; Nakagawa, Shigeaki
Nippon Genshiryoku Gakkai Wabun Rombunshi 5(1), p.57-67(2006) ; (JAEA-J 00726)

High Temperature Engineering Test Reactor(HTTR) of high temperature gas-cooled reactor at Japan Atomic Energy Agency(JAEA) achieved the reactor outlet coolant temperature of 950^°C for the first time in the world at Apr. 19, 2004. To ensure the thermal integrity of fuel in high temperature test operation, it is necessary that fuel temperature is designed appropriately by fuel temperature designing method, and that estimated maximum fuel temperature is lower than the thermal limit temperature. In this report, by constructing newly a realistic core-shape representing model, the current fuel temperature estimation model is improved. Moreover fuel temperature in high-temperature test operation is estimated with the newly-constructed model, and it is confirmed that estimated maximum fuel temperature in high temperature test operation is lower than the thermal limit temperature.

34000601
Development of calculation program for diffractive coefficient and investigation of proper choice for analytical method (in Japanese)
Miyauchi, Shinji*; Koike, Masato
Shimazu Hyoron 62(3·4), p.193-199(2006) ; (JAEA-J 00729)

Though many analytical methods for diffractive gratings have been suggested, all of them have to need smaller elements or upper order Fourie coefficients for enough accuracy calculation. Generally it comes to a huge matrix equation, so they have to be more or less restricted by computer power (CPU speed, amount of Memory). Here we briefly introduce Rigorous Coupled Wave Analysis (RCWA) and Boundary Element Method (BEM), which are representative analytical methods for diffraction gratings. Then we theoretically consider proper wave-length range for each method and show that propriety by comparison of diffractive efficiency measurement and its analytical result.

34000602
Development of a vacuum leak test method for large-scale superconducting magnet test facilities (in Japanese)
Kawano, Katsumi; Hamada, Kazuya; Okuno, Kiyoshi; Kato, Takashi
Teion Kogaku 41(3), p.105-112(2006) ; (JAEA-J 00730)

34000603
Optimization of JK2LB chemical component for ITER central solenoid jacket material (in Japanese)
Hamada, Kazuya; Nakajima, Hideo; Kawano, Katsumi; Takano, Katsutoshi; Tsutsumi, Fumiaki; Okuno, Kiyoshi; Suzuki, Tomio; Fujitsuna, Nobuyuki*
Teion Kogaku 41(3), p.131-138(2006) ; (JAEA-J 00731)

34000604
Gas yield and mechanical property of super insulator (polyimide and polyester) after γ ray irradiation (in Japanese)
Teshigawara, Makoto; Kusano, Joichi; Morishita, Norio; Maekawa, Fujio; Kato, Takashi; Hosoyama, Kenji*; Hara, Kazufumi*; Kojima, Yuji*
Teion Kogaku 41(3), p.99-104(2006) ; (JAEA-J 00732)

Japanese intense spallation neutron source (JSNS) driven by 3 GeV protons with power of 1 MW is constructed under the joint project of Japan Atomic Energy Agency and High Energy Accelerator Research Organization. Supercritical hydrogen of around 20K with 2 MPa is selected as a neutron moderator material and cryogenic hydrogen transfer lines are constructed from the moderators to the refrigerator. Then, a super insulator (SI) is adopted to reduce heat load in the hydrogen transfer lines. We performed irradiation test of SI using ⁶⁰Co gamma ray to evaluate the irradiation effect. Two kinds of super insulator (polyimide and polyester) coated both sides by aluminum were irradiated. After gamma ray irradiation, tensile test and gas yield measurement of super insulator were performed. Polyester based SI became brittle at about 10 MGy, on the other hand, polyimide based SI did not loss ductility so much even 80 MGy. Polyester based SI generated gas yield higher than that of polyimide based SI about one order of magnitude. We developed the gas analysis method by using a Q-mass and a mass-flow, providing to identify the unknown gas (i.e. H₂O) effectively compared to a gas chromatography method.

34000605
Dielectric study on dynamics of electron-beam-induced gelation of hdroxypropylmethylcellulose (HPMC) (in Japanese)
Morishita, Satoshi*; Umino, Yuya*; Kita, Rio*; Shinyashiki, Naoki*; Yagihara, Shin*; Furusawa, Kazuya*; Dobashi, Toshiaki*; Nagasawa, Naotsugu
Tokai Daigaku Kiyo Rigakubu 41, p.105-112(2006) ; (JAEA-J 00733)

Dielectric relaxation measurements were performed for the systems of hydroxypropylmethylcellulose (HPMC) in 1,4-dioxane and HPMC gel immersed in 1,4-dioxane. The HPMC gel was prepared by an electron beam irradiation for HPMC aqueous solution. Two relaxation processes were observed for both samples. Higher frequency process of each sample in the range of 300 kHz - 100 MHz was attributed to a chain motion of HPMC, while lower frequency process observed for the HPMC gel in the range 100 Hz - 300 kHz was significantly larger than the HPMC in dioxane. This observation indicates that DC conductivity due to the beam irradiation had a pronounced effect for the slower relaxation process.

34000606
Lattice and collimation system for J-PARC
Kinsho, Michikazu
AIP Conference Proceedings 773 , p.45-49(2005) ; (JAEA-J 00734)

JAERI and KEK have been working on the J-PARC project for a high intensity proton accelerator. The accelerator complex consists of a 400MeV linac, a 3GeV rapid cycle synchrotron, and a 50GeV synchrotron ring. The major requirements for the accelerator are summarized as follows, (1) The accelerator should provide the 1MW beam with a repetition rate of 25 Hz and a pulse length less than 1 us to the full use of pulsed spallation neutrons. (2) It should provide the several ten GeV beams with a beam power of 0.75MW for nuclear and particle physics experiments. As for the design of such a high intensity proton accelerator, from the experience of the past accelerator operation, the average beam loss should be kept at an order of 1W/m with a view to hands-on maintenance. Accordingly, there are several kinds of beam collimator in each accelerator and beam transport lines to minimize and localize the beam loss. We reported mainly the design concept and simulation results of the beam loss for each section.

34000607
Systematic calibration of beam position monitor in the high intensity proton accelerator (J-PARC) linac
Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; Toyama, Takeshi*; Kamikubota, Norihiko*; Nigorikawa, Kazuyuki*; Tanaka, Mikio*; Yoshikawa, Hiroshi
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004) , p.429-431(2004) ; (JAEA-J 00741)

As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.1~1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.

34000608
Status of the J-PARC linac, initial results and upgrade plan
Yamazaki, Yoshishige
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004) , p.554-558(2004) ; (JAEA-J 00742)

34000609
RF reference distribution system for the J-PARC linac
Kobayashi, Tetsuya; Chishiro, Etsuji; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004) , p.727-729(2004) ; (JAEA-J 00743)

J-PARC (Japan Proton Accelerator Complex) linac, which is 300 m long, consists of 324 MHz accelerating section of the upstream and 972 MHz section (as future plan) of the downstream. In the klystron gallery, totally about 60 RF source control stations will stand for the klystrons and solid-state amplifiers. The error of the accelerating field must be within ± 1 degree in phase and ± 1% in amplitude. Thus, the high phase stability is required to the RF reference for all of the low-level RF control systems and the beam monitor systems. This paper presents a final design of the RF reference distribution system for this linac. Our objective for the phase stability of the reference aims at less than ± 0.3 degrees at a 972 MHz frequency.

34000610
Cold-model tests and fabrication status for J-PARC ACS
Ao, Hiroyuki; Akikawa, Hisashi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige ; Ikegami, Masanori*; Noguchi, Shuichi*; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004) , p.75-77(2004) ; (JAEA-J 00744)

The J-PARC (Japan Proton Accelerator Research Complex) LINAC will be commissioned with energy of 181-MeV using 50-keV ion source, 3-MeV RFQ, 50-MeV DTL and 181-MeV SDTL (Separated DTL) on September 2006. It is planed to be upgraded by using a 400-MeV ACS (Annular Coupled Structure), which is a high-beta structure most suitable for the J-PARC, in a few years from the commissioning. The first ACS type cavity, which will be used as the first buncher between the SDTL and the ACS, is under fabrication. Detailed design and tuning procedure of ACS cavities has been studied with RF simulation analysis and cold-model measurements. The results of cold-model measurements, fabrication status, and related development items are described in this paper.

34000611
Rapid cycling synchrotron of J-PARC
Suzuki, Hiromitsu
Proceedings of 3rd Asian Particle Accelerator Conference (APAC 2004) , p.499-501(2004) ; (JAEA-J 00745)

JAERI and KEK are constrting J-PARC. The accelerator complex consists of a 400 MeV linac, a 3 GeV rapid cycling synchrotron ring (RCS) and a 50 GeV synchrotron ring (MR). The RCS ring accelerates a 400 MeV proton beam from the linac up to 3 GeV and supplies the beam to the MR and a MLF (material and life science facility). The MLF has a neutron production target in order to produce a high intensity neutron beam. For this purpose, the RCS aims to generate a high power proton beam of 1 MW. The construction of the RCS started in 2002. All the components were ordered in the fiscal year of 2002 and 2003. The budged is started in the fiscal year of 2002 and finished in that of 2006. The building will be accomplished in April 2005, and many components of RCS will be installed and tested from May 2005 to April 2007. The beam commissioning of RCS will be started in May 2007. This paper presents the design and status of RCS.

34000612
Development of superconducting proton linac for ADS
Ouchi, Nobuo; Akaoka, Nobuo*; Asano, Hiroyuki*; Chishiro, Etsuji; Namekawa, Yuya*; Suzuki, Hiroyuki*; Ueno, Tomoaki*; Noguchi, Shuichi*; Kako, Eiji*; Ouchi, Norihito*; Saito, Kenji*; Shishido, Toshio*; Tsuchiya, Kiyosumi*; Okubo, Koichi*; Matsuoka, Masanori*; Sennyu, Katsuya*; Murai, Takashi*; Otani, Toshihiro*; Tsukishima, Chihiro*
Proceedings of 4th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators , p.175-183(2005) ; (JAEA-J 00746)

34000613
Investigation of photo neutralization efficiency of high intensity H^- beam with Nd:YAG laser in J-PARC
Tomisawa, Tetsuo; Akikawa, Hisashi; Sato, Susumu; Ueno, Akira; Kondo, Yasuhiro; Oigawa, Hiroyuki; Sasa, Toshinobu; Hasegawa, Kazuo; Lee, S.*; Igarashi, Zenei*; Toyama, Takeshi*; Ikegami, Masanori*
Proceedings of 7th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators (DIPAC 2005) , p.275-277(2005) ; (JAEA-J 00747)

The photo neutralization method with Nd:YAG laser for negative hydrogen ions has been expected as an available candidate for the transverse beam profile measurement. The fraction of photo detached electron can also be used for charge exchange procedure to extract very low power proton beam for Transmutation Experimental Facility in J-PARC. The laser system has advantages of maintenance and radiation hardness in high intensity proton accelerators. In order to establish the low power beam extraction system and beam profile monitor, the photo neutralization efficiency must be surveyed in practical beam line with high intensity H^- beam. In this paper, an experimental set-up and preliminary results of photo neutralization method for intense H^- beam in J-PARC MEBT1 are described.

34000614
Challenges facing the generation of MW proton beams using rapid cycling synchrotrons
Irie, Yoshiro
Proceedings of 9th European Particle Accelerator Conference (EPAC 2004) , p.113-117(2004) ; (JAEA-J 00748)

The MW proton source using rapid cycling synchrotron (RCS) has many challenging aspects, such as (1) large aperture magnets and much higher RF voltages per turn due to a low energy injection and a large and rapid swing of the magnetic field, (2) field tracking between many magnet-families under slightly saturated conditions, (3) RF trapping with fundamental and higher harmonic cavities, (4) H- charge stripping foil, (5) large acceptance injection and extraction straights, (6) beam loss collection, and (7) beam instabilities. These are discussed in details mainly on the basis of the J-PARC 3GeV RCS, which is under construction in Japan. Issues (3) to (7) are common with another scheme of MW spallation neutron source, i.e. full-energy linac + accumulator ring. Comparisons with the SNS design in the US are then made. Reliability/availability of these machines is very important theme which finally determines the successful operations. From the experiences in the existing machines, we will discuss the factors necessary toward the better performance.

34000615
Design of the beam transportation line from the linac to the 3-GeV RCS for J-PARC
Okawa, Tomohiro*; Ikegami, Masanori*
Proceedings of 9th European Particle Accelerator Conference (EPAC 2004) , p.1342-1344(2004) ; (JAEA-J 00749)

The accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC, consist of a 180-MeV linac, a 3-GeV RCS (Rapid Cycling Synchrotorn), and a 50-GeV MR (Main Ring). L3BT is a beam transport line from the linac to the RCS. To meet the requirement for the beam loss minimization, the L3BT does not only connect the linac to the 3GeV RCS, but also modifies the linac beam to be acceptable for the RCS. The required beam parameters at the injection point of the RCS are momentum spread <± 0.1% and transverse emittance <4π mm·mrad. To achieve these beam qualities, the L3BT should have following functions: momentum compaction, transverse halo scraping and beam diagnostics. In this paper, results of the design and beam simulation of the L3BT are presented.

34000616
J-PARC construction and its linac commissioning
Yamazaki, Yoshishige
Proceedings of 9th European Particle Accelerator Conference (EPAC 2004) , p.1351-1353(2004) ; (JAEA-J 00750)

The J-PARC (Japan Proton Accelerator Research Complex) is under construction in JAERI Tokai site. The beam commissioning will start there by the end of 2006. Prior to this, the front end of the linac was beam-commissioned in 2003 at KEK. The negative hydrogen beam with a peak current of 30 mA was accelerated up to 20 MeV by the first tank of the three DTL's following the 3-MeV RFQ linac. The 324-MHz DTL contains the electro quadrupole magnets with water-cooling channels specially fabricated by means of electroforming and wire-cutting technologies. The construction status of the J-PARC accelerator is also presented.

34000617
High average power and high energy laser-diode pumped Nd:YAG laser with a phase conjugate mirror and its application
Kiriyama, Hiromitsu
Recent Developments in Lasers and their Applications , p.31-51(2006) ; (JAEA-J 00751)

34000618
Fundamental theory for application of ion beam (in Japanese)
Taguchi, Mitsumasa
Hoshasen Kagaku No Susume; Denshi, Ion, Hikari No Bimu Ga Kurashi O Kaeru, Sangyo O Tsukuru , p.127-129(2006) ; (JAEA-J 00759)

34000619
Microdisimetry; Dose measurement and evaluation in micro volume (in Japanese)
Taguchi, Mitsumasa
Hoshasen Kagaku No Susume; Denshi, Ion, Hikari No Bimu Ga Kurashi O Kaeru, Sangyo O Tsukuru , p.180-182(2006) ; (JAEA-J 00760)

34000620
Environmental conservation technology using ionizing radiation for water treatment (in Japanese)
Taguchi, Mitsumasa
Hoshasen Kagaku No Susume; Denshi, Ion, Hikari No Bimu Ga Kurashi O Kaeru, Sangyo O Tsukuru , p.78-80(2006) ; (JAEA-J 00761)

34000621
R&D status for J-PARC ACS (in Japanese)
Ao, Hiroyuki; Ueno, Akira; Morishita, Takatoshi; Hasegawa, Kazuo; Yamazaki, Yoshishige ; Ikegami, Masanori*; Hayashizaki, Noriyosu*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan , p.323-325(2004) ; (JAEA-J 00762)

34000622
Orbit following calculation of energetic ions in the design of ferritic insertion in the JT-60U
Shinohara, Koji; Suzuki, Yutaka; Sakurai, Shinji; Masaki, Kei; Fujita, Takaaki; Miura, Yukitoshi
Plasma and Fusion Research (Internet) 1(2), p.007_1-007_8(2006) ; (JAEA-J 00764)

For the further pursuit of the steady-state advanced tokamak research, the ferritic insertion was proposed to reduce the toroidal field (TF) ripple. The reduction of energetic ion loss due to the TF ripple reduction brings: (1)the enhancement of the heating and current drive effective efficiency, (2)the extended pulse length and the improved efficiency of RF injection due to the reduced heat flux on antennas and improved coupling between antennas and a plasma, (3)the availability of a wall stabilization without losing heating power, and (4)the possibility of an enhanced availability of the rotation control to improve the MHD stability and transport. The design work of ferritic inserts was carried out aiming at an effective, machine-safe, and short-term installation. Here, the design work for ferritic inserts is described from the viewpoint of the behavior of energetic ions. The confinement of energetic ions and the absence of the unfavorable heat flux on the first wall was assessed by using the Fully three Dimensional magnetic field OFMC code, which was developed for a ferrite insert program in JFT-2M. In the final design, the absorbed power in the neutral beam injection is improved by a factor of about 1.3 in a large volume plasma with Bt0 = 1.9T.

34000623
A Broad-band RF buncher cavity using finemet cut cores for ion beams
Watanabe, Masao; Chiba, Yoshiaki*; Koseki, Tadashi*; Katayama, Takeshi*; Oshiro, Yukimitsu*; Watanabe, Shinichi*
Proceedings of 17th International Conference on Cyclotrons and Their Applications 2004 (CYCLOTRONS 2004) (CD-ROM) , 3p.(2005) ; (JAEA-J 00766)

A broad-band rf cavity as a buncher of ion beams has been developed. Operating frequencies of the cavity is between 18 and 45 MHz. The cavity was installed in the beam transport line of the Hi-ECR ion source system in CNS for the beam test. Beam structure of 30 MHz was successfully observed for 10 keV proton beam.

34000624
The Extraction kicker system of the RCS in J-PARC
Kamiya, Junichiro; Takayanagi, Tomohiro; Kawakubo, Toshimichi*; Murasugi, Shigeru*; Nakamura, Eiji*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.1009-1011(2005) ; (JAEA-J 00768)

The kicker magnets are installed in the vacuum chamber at the extraction section of the RCS (Rapid Cycling Synchrotron) in J-PARC (Japan Proton Accelerator Research Complex) facility. They kick the 3GeV proton beam to the extraction septum magnets followed by a downstream beam transport line. The RCS is designed to achieve the 1MW beam power with minimum loss. Therefore, the kicker is required to have a wide aperture, UHV (ultra-high vacuum) in its chamber, and uniformity of magnetic field. The wide aperture requires large exciting current and the use environment of the thyratron is very tough. Therefore aging run was found out to be needed. And the uniformity of the magnetic field was improved by changing length of the conductors. In order to achieve the UHV, we succeeded in reducing outgas from components of the magnet. In this paper, we will introduce the specification of the extraction kicker system in the RCS, and report countermeasure against the technical challenge described above.

34000625
Design of the pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC
Takayanagi, Tomohiro; Irie, Yoshiro; Kamiya, Junichiro; Watanabe, Masao; Watanabe, Yasuhiro; Ueno, Tomoaki*; Noda, Fumiaki*; Saha, P. K.; Sakai, Izumi*; Kawakubo, Toshimichi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.1048-1050(2005) ; (JAEA-J 00769)

The pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC has been designed. The injection system consists of the pulsed bending magnets, which are four horizontal bending magnets (shift bump) and four horizontal painting magnets (h-paint bump) for the injection bump orbit, and two vertical painting magnets (v-paint magnet). The injection beam energy and the extraction beam power are 400 MeV and 1 MW at 25 Hz repetition rate, respectively. The acceptance to include the injection beam, the painting beam and the circulating beam at the shift bump points is a 388 mm wide and a 242 mm high. The shift bump has been designed using a 3D magnetic analysis code, which accomplished less than 0.4 % field deviation under 0.26 T excitation level.

34000626
γ-ray irradiation experiments of collimator key components for the 3GeV-RCS of J-PARC
Kinsho, Michikazu; Ogiwara, Norio; Masukawa, Fumihiro; Takeda, Osamu; Yamamoto, Kazami; Kusano, Joichi
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.1309-1311(2005) ; (JAEA-J 00770)

It was success to develop the radiation resistant components using for beam collimator. Turbo molecular pump could be operated more than 15 MGy of γ ray irradiation dose. Stepping motor developed at JAERI could be operated with good performance in the γ ray dose of more than 70 MGy. PEEK sheathed cables and connector have kept good performance during γ ray irradiation more than the dose of 10 MGy. It was cleared that the function of the heat pipe disappeared at 30 kGy γ ray irradiation dose.

34000627
The Impedance of the ceramic chamber in J-PARC
Shobuda, Yoshihiro; Chin, Y. H.*; Omi, Kazuhito*; Toyama, Takeshi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.1898-1900(2005) ; (JAEA-J 00771)

At 3GeV RCS(Rapid Cycle Synchrotron) in J-PARC, the ceramic chamber is adopted to aviod the excess eddy current. This ceramic chamber is surrounded by Cu-stripes to supress the leak field caused by the beam. The inner surface of the chamber is coated with TiN to suppress the secondary electron emission. In order to discuss the beam instability, we have to calculate the impedance for this chamber. Previously, the impedance was calculated by replacing the Cu-stripes to the conducting beam pipe. In this paper we deal with Cu-stripes realistically, and compare the results with the previous results. The resistivity of Cu-stripes and the TiN are also considered.

34000628
Alumina ceramics vacuum duct for the 3GeV-RCS of the J-PARC
Kinsho, Michikazu; Ogiwara, Norio; Saito, Yoshio*; Kabeya, Zenzaburo*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.2604-2606(2005) ; (JAEA-J 00772)

It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5m-long duct with a circular cross section for use in the quadrupole magnet, the other being 3.5m-long and bending 15 degrees, with a race-track cross section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.5-0.8 m in length by brazing. The alumina ceramics ducts have copper stripes on the outside surface of the ducts to reduce the duct impedance. In order to reduce emission of secondary electrons when protons or electrons strike the surface, TiN film is coated on the inside surface of the ducts.

34000629
RF tuning and fabrication status of the first module for J-PARC ACS
Ao, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige ; Ikegami, Masanori*; Paramonov, V.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.2684-2686(2005) ; (JAEA-J 00773)

J-PARC Linac starts with 180-MeV SDTL temporary, and it is upgraded to 400-MeV with 21 ACS (Annular Coupled Structure) modules and two ACS bunchers and two debunchers. First buncher module is under fabrication, and second buncher and a few accelerating modules are also planed until FY2006. The first ACS module consists of two 5-cell ACS tanks and a 5-cell 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.

34000630
The Status of optics design and beam dynamics study in J-PARC RCS
Noda, Fumiaki*; Hocchi, Hideaki; Saha, P. K.; Shobuda, Yoshihiro; Yamamoto, Kazami; Hayashi, Naoki; Kishiro, Junichi; Machida, Shinji*; Molodojentsev, A. Y.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.2759-2761(2005) ; (JAEA-J 00774)

34000631
Developments of the calibration tools for beam position monitor at J-PARC LINAC
Sato, Susumu; Tomisawa, Tetsuo; Akikawa, Hisashi; Ueno, Akira; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Toyama, Takeshi*; Kamikubota, Norihiko*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.2777-2779(2005) ; (JAEA-J 00775)

The J-PARC LINAC requires for fine control of beam position to minimize beam loss. So that BPMs need to be calibrated with the accuracy of about a hundred micro-meters. The accuracy of BPMs are calibrated with the calibration tool and real beam. In this paper, details of these developments around BPMs are to be reported.

34000632
An Alignment of J-PARC linac
Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.2851-2853(2005) ; (JAEA-J 00776)

In J-PARC linac, a precise alignment of accelerator components is essential for high quality beam acceleration. Markings have been placed on the floor, which act as a reference for the initial alignment at the installation. For a straight line alignment, the wire position sensor is placed on the offset position with respect to the beam center by a target holder. The hydrostatic levering system is used for watching the floor elevation over the long period.

34000633
Development of the beam diagnostics system for the J-PARC rapid-cycling synchrotron
Hayashi, Naoki; Hiroki, Seiji; Kishiro, Junichi*; Teruyama, Yuzo*; Toyokawa, Ryoji; Arakawa, Dai*; Lee, S.*; Miura, Takako*; Toyama, Takeshi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.299-301(2005) ; (JAEA-J 00777)

Development of the beam diagnostics system for the J-PARC (Japan Proton Accelerator Research Complex) Rapid-Cycling Synchrotron is described. The system consists of Beam Position Monitor (BPM), Beam Loss Monitor (BLM), Current monitors (DCCT, SCT, MCT, FCT, WCM), Tune meter system, 324MHz-BPM, Profile monitor, and Halo monitor. BPM electrode is electro-static type and its electronics is designed for both COD and turn-by-turn measurements. Five current monitors have different time constants in order to cover wide frequency range. The tune meter is consisted of RFKO and the beam pick-up electrode. For the continuous injected beam monitoring, 324MHz-BPM detects Linac frequency. Two types of profile monitor are multi-wire for low intensity tuning and the residual gas monitor for non-destructive measurement.

34000634
Beam dynamics design of the L3BT for J-PARC
Okawa, Tomohiro*; Ikegami, Masanori*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.3091-3093(2005) ; (JAEA-J 00778)

L3BT is beam transportation line from the linac to the 3-GeV RCS which is the part of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. In this paper, especially results of the beam simulation of the injection section of the L3BT are presented. The injection section is necessary for a successful adjustment to the transported beam to the required parameters for ring injection. The matching of beams envelopes and dispersion function for space charge dominative beams are also discussed.

34000635
Present design and calculation for the injection-dump line of the RCS at J-PARC
Saha, P. K.; Noda, Fumiaki*; Irie, Yoshiro; Hocchi, Hideaki; Takayanagi, Tomohiro; Hayashi, Naoki; Machida, Shinji*; Sakai, Izumi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.3739-3741(2005) ; (JAEA-J 00779)

The RCS(rapid cycling synchrotron) of J-PARC(Japan proton accelerator research complex) acts as an injector to the main ring as well as a high-power beam for the spallation neutron source at a repetition rate of 25 Hz, where at present the injection and the extraction beam energy are chosen to be 0.181 GeV and 3.0 GeV, respectively. The present work concerns on the present design and calculations for the injection-dump line of the RCS, which includes, (1) an accurate aperture list of all elements taking into account a wide range of the betatron tune, effect of changing injection modes, multiple trajectories of different particles after the charge-exchange foil(like H0 from the H- and H- beam itself)and (2) an accurate estimation of the uncontrolled beam losses especially from the H0-excited states, multiple coulomb scattering at the charge-exchange foil and also the lorentz stripping loss at the septum magnets so as to optimize them concerning mainly the radiation issues as well as for the hands-on maintenance.

34000636
Evaluation of nonlinear effects in the 3-GeV rapid cycling synchrotron of J-PARC
Hocchi, Hideaki; Noda, Fumiaki*; Tani, Norio; Kishiro, Junichi*; Machida, Shinji*; Molodojentsev, A. Y.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM) , p.916-918(2005) ; (JAEA-J 00780)

34000637
Measurement of toroidal structure of electron temperature with electron cyclotron emission diagnostic in JT-60U
Isayama, Akihiko; Oyama, Naoyuki; Urano, Hajime; JT-60 Team
Proceedings of 21th IEEE/NPSS Symposium on Fusion Engineering (SOFE 2005) (CD-ROM) , 4p.(2006) ; (JAEA-J 00781)

34000638
Current status of experimental study and device modifications in JT-60U
Kurihara, Kenichi; JT-60 Team
Proceedings of 21th IEEE/NPSS Symposium on Fusion Engineering (SOFE 2005) (CD-ROM) , 6p.(2005) ; (JAEA-J 00782)

Since JT-60 is expected to explore more advanced operation scenarios, the discharge pulse length and the duration time of additional NBI/RF heating were extended to 65 s and 30 s/60 s, respectively, in 2003. The experimental campaign in 2003-2004 has ended up with the following significant results: (a) The high bootstrap current ratio of 75 % was sustained for 7.4 s in an R/S plasma. (b) The quasi-steady state beta value was increased to 3.0 for a pulse of 6.2 s with NTM suppression by ECCD, etc. For further exploration toward high performance plasmas, the following modifications have been conducted: (1) To minimize the power loss at the region of toroidal field ripple, the 8Cr ferritic steel tiles are being equipped on the first wall of the vacuum vessel. (2) A new current profile reproduction method will be installed in the plasma control system. In the symposium, the current status of plasma experimental study will be presented together with on-going device modifications in JT-60.

34000639
Status of a superconducting linac for the J-PARC ADS
Hasegawa, Kazuo; Ouchi, Nobuo; Chishiro, Etsuji; Kako, Eiji*; Noguchi, Shuichi*; Ouchi, Norihito*; Shishido, Toshio*; Tsuchiya, Kiyosumi*
Proceedings of 34th ICFA Advanced Beam Dynamics Workshop on High Power Superconducting Ion, Proton and Multi-Species Linacs (HPSL 2005) (Internet) , 5p.(2005) ; (JAEA-J 00783)

34000640
Review of the J-PARC project
Hasegawa, Kazuo
Proceedings of 34th ICFA Advanced Beam Dynamics Workshop on High Power Superconducting Ion, Proton and Multi-Species Linacs (HPSL 2005) (Internet) , 7p.(2005) ; (JAEA-J 00784)

34000641
Order-disorder phase transition of Sn/Ge(111) surface studied by reflection high-energy positron diffraction
Fukaya, Yuki; Kawasuso, Atsuo; Ichimiya, Ayahiko
e-Journal of Surface Science and Nanotechnology (Internet) 4, p.435-438(2006) ; (JAEA-J 00785)

34000642
Study of InAs/GaAs(001) nanoisland growth process by in-situ and real-time X-ray diffraction
Takahashi, Masamitsu; Kaizu, Toshiyuki; Mizuki, Junichiro
e-Journal of Surface Science and Nanotechnology (Internet) (4), p.426-430(2006) ; (JAEA-J 00786)

A monitoring technique for molecular beam epitaxial growth of InAs/GaAs(001) nanoislands is presented. With the help of a combination of synchrotron radiation and a two-dimensional X-ray detector, X-ray diffraction intensity mappings in the reciprocal space have been measured during growth at a rate of 9.6 s per frame. This method provides information on strain distribution and height of Stranski-Krastanov islands under the in situ condition. Because the use of X-rays is not hindered by ambient pressure, this technique is suitable for industry-oriented applications such as organometallic vapor-phase epitaxy as well.

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