JAEA Abstracts

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

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

February 2006

34000072
Ultraviolet photolysis of urine for suppression of color quenching prior to liquid scintillation counting of tritium
Watanabe, Yoko; Kuwabara, Jun
Analytical and Bioanalytical Chemistry 384(2), p.547-550(2006) ; (JAEA-J 00221)

In order to reduce the color quenching in the measurement of tritium in urine by liquid scintillation counter (LSC), ultraviolet (UV) irradiation was applied to decompose the organic substances in the sample. Urine was decolorized under UV irradiation in the presence of hydrogen peroxide. As a result, color quenching was considerably suppressed and higher counting efficiency of tritium was obtained. This UV treatment made it possible to increase the urine content in the sample from 2% to 40%(v/v) without significant decrease of counting efficiency. Either higher sensitivity or shorter analysis time was achieved in the tritium measurement by the augumentation of urine content. When the measurement time was 30 min, the detection limit of tritium defined as 3s was 0.03Bq/ml. At the expense of some sensitivity (set at detection limit of 0.3Bq/ml), the measurement time was shortened to 0.5 min. These results will make a great improvement to routine tritium monitoring as well as to emergency monitoring in mass tritium exposure.

34000073
Interaction of nitrogen with vacancy defects in N⁺-implanted ZnO studied using a slow positron beam
Chen, Z. Q.; Maekawa, Masaki; Kawasuso, Atsuo; Suzuki, Ryoichi*; Odaira, Toshiyuki*
Applied Physics Letters 87(9), p.091910_1-091910_3(2005) ; (JAEA-J 00222)

Zinc oxide crystals were implanted with N⁺, O⁺, and co-implanted with O⁺/N⁺ ions. Positron annihilation measurements show the introduction of vacancy clusters upon implantation. In the N⁺-implanted sample, these vacancy clusters are only partially annealed at 800^°C as compared to their full recovery in the O⁺-implanted sample, suggesting a strong interaction between nitrogen and vacancy clusters. At 1000-1100^°C, nitrogen also forms stable complexes with thermally generated vacancies. To remove all the detectable vacancy defects, a high temperature annealing at 1250^°C is needed. Furthermore, Hall measurements of this sample show n-type conductivity though nitrogen is expected as acceptors. On the contrary, in the O⁺/N⁺ co-implanted sample, most vacancy clusters disappear at 800^°C. Probably oxygen scavenges nitrogen to form N-O complexes and hence enhance the annealing of vacancy clusters. A highly compensated semi-insulating layer is formed in the co-implanted sample.

34000074
Experimental study on spatial uniformity of H^- ion beam in a large negative ion source
Hanada, Masaya; Seki, Takayoshi*; Takado, Naoyuki*; Inoue, Takashi; Morishita, Takatoshi; Mizuno, Takatoshi*; Hatayama, Akiyoshi*; Imai, Tsuyoshi*; Kashiwagi, Mieko; Sakamoto, Keishi; Taniguchi, Masaki; Watanabe, Kazuhiro
Fusion Engineering and Design 74(1-4), p.311-317(2005) ; (JAEA-J 00223)

34000075
Recent progress of negative ion based neutral beam injector for JT-60U
Umeda, Naotaka; Yamamoto, Takumi; Hanada, Masaya; Grisham, L. R.*; Kawai, Mikito; Oga, Tokumichi; Akino, Noboru; Inoue, Takashi; Kazawa, Minoru; Kikuchi, Katsumi*; Mogaki, Kazuhiko; Yamazaki, Haruyuki*; Watanabe, Kazuhiro; Ikeda, Yoshitaka
Fusion Engineering and Design 74(1-4), p.385-390(2005) ; (JAEA-J 00224)

In negative ion based neutral beam injector (N-NBI) for JT-60U, some modifications for extent pulse duration from 10 second, which is design value, to 30 second was conducted. Main limit to prevent pulse extension was heat loads onto grounded grid in an ion source and onto beam limiter placed at 22 m from the ion source. To reduce these heat loads, beam extraction area was optimized and the limiter was changed to one which had about twice thermal capacity. As a result of these modifications, the temperature rise of the water which was cooling grounded grid could be suppressed under 40 degree, which can operate in steady state condition. The temperature rise of the limiter could be restricted to 60%. Untill now the beam pulse extended to 17 second of 1.6MW power at 366keV energy, and injection of 30 seconds will be achieved in next experiment.

34000076
Temperature dependence of the transmission loss in KU-1 and KS-4V quartz glasses for the ITER diagnostic window
Nishitani, Takeo; Sugie, Tatsuo; Morishita, Norio; Yokoo, Noriko*
Fusion Engineering and Design 74(1-4), p.871-874(2005) ; (JAEA-J 00225)

34000077
Updating the design of the feeder components for the ITER magnet system
Yoshida, Kiyoshi; Takahashi, Yoshikazu; Isono, Takaaki; Mitchell, N.*
Fusion Engineering and Design 75-79, p.241-247(2005) ; (JAEA-J 00226)

The ITER superconducting magnet system stores energy of 50 GJ during plasma operation, and generates an average heat load of 23 kW at 4 K to cryoplant. The helium is distributed to the coil through 30 separate feeder lines. The feeders also contain the electrical supplies to the coil and are integrated into the current lead transition to room temperature. The interface components between the coils and the service facilities (power supply and cryogenic plant) consist of the in-cryostat feeders, the cryostat feedthroughs, and the coil terminal boxes (CTBs). The cryostat feedthroughs with S-bend boxes allow thermal contraction of the magnet system. The layout of the in-cryostat feeders takes into consideration routing restrictions in the cryostat and initial assembly with other Tokamak components. The forced-flow-cooled current leads with a conventional copper heat exchanger in the CTBs are adapted to fit in the limited space in the building. This paper presents the latest design concept and parameters of the feeder components.

34000078
Behavior on Li₂TiO₃ under varied surface condition
Olivares, R.*; Oda, Takuji*; Oya, Yasuhisa*; Tanaka, Satoru*; Tsuchiya, Kunihiko
Fusion Engineering and Design 75-79, p.765-768(2005) ; (JAEA-J 00227)

34000079
The HFR Petten high dose irradiation programme of beryllium for blanket application
Hegeman, J. B. J.*; Van der Laan, J. G.*; Kawamura, Hiroshi; M"oslang, A.*; Kupriyanov, I.*; Uchida, Munenori*; Hayashi, Kimio
Fusion Engineering and Design 75-79, p.769-773(2005) ; (JAEA-J 00228)

34000080
Thermal and thermal-stress analyses of IFMIF liquid lithium target assembly
Ida, Mizuho*; Nakamura, Hiroo; Shimizu, Katsusuke*; Yamamura, Toshio*
Fusion Engineering and Design 75-79, p.847-851(2005) ; (JAEA-J 00229)

34000081
Fatigue assessment of the ITER TF coil case based on JJ1 fatigue tests
Hamada, Kazuya; Nakajima, Hideo; Takano, Katsutoshi*; Kudo, Yusuke; Tsutsumi, Fumiaki*; Okuno, Kiyoshi; Jong, C.*
Fusion Engineering and Design 75-79, p.87-91(2005) ; (JAEA-J 00230)

34000082
Effects of gelation and sintering conditions on granulation of Li₂TiO₃ pebbles from Li-Ti complex solution
Tsuchiya, Kunihiko; Kawamura, Hiroshi; Casadio, S.*; Alvani, C.*
Fusion Engineering and Design 75-79, p.877-880(2005) ; (JAEA-J 00231)

34000083
Non-stoichiometry of Li₂TiO₃ under hydrogen atmosphere condition
Hoshino, Tsuyoshi; Tsuchiya, Kunihiko; Hayashi, Kimio; Terai, Takayuki*; Tanaka, Satoru*; Takahashi, Yoichi*
Fusion Engineering and Design 75-79, p.939-943(2005) ; (JAEA-J 00232)

34000084
Synchrotron radiation photoelectron emission study of SiO₂ film formed by a hyperthermal O-atom beam at room temperature
Tagawa, Masahito*; Sogo, Chie*; Yokota, Kumiko*; Hachiue, Shunsuke; Yoshigoe, Akitaka; Teraoka, Yuden
Japanese Journal of Applied Physics 44(12), p.8300-8304(2005) ; (JAEA-J 00233)

Si oxide layers formed on Si(001) substrates by irradiation of hyperthermal oxygen atomic beams at room temperature were analysed at the JAERI soft X-ray beamline by photoemission spectroscopy. It was found that sub-oxide components were scarcely observed in the Si oxide layers formed by the atomic oxygen beam.

34000085
Selective OD bond dissociation of HOD; Photodissociation of vibrationally excited HOD in the 5ν_OD state
Akagi, Hiroshi; Fukazawa, Hiroshi; Yokoyama, Keiichi; Yokoyama, Atsushi
Journal of Chemical Physics 123(18), p.184305_1-184305_7(2005) ; (JAEA-J 00234)

Vibrationally excited HOD in the fourth overtone state of the OD-stretching mode (5ν_OD) has been photodissociated by ultraviolet photolysis at ca. 243.1 nm. Branching ratio between the OH- and OD-bond dissociation channels has been determined by detecting the H and D atoms. The OD-bond dissociation is the dominant channel, with the yield of H atom generated by the photolysis being below the detection limit.

34000086
Synthesis and characterization of copper hydroxide acetate with a layered discoid crystal
Kozai, Naofumi; Mitamura, Hisayoshi; Fukuyama, Hiroyasu; Esaka, Fumitaka; Komarneni, S.*
Journal of Materials Research 20(11), p.2997-3003(2005) ; (JAEA-J 00235)

Layered transition metal hydroxide salt (LTMHS) is a group of anion-exchangeable layered compounds. LTMHSs have lately attraced attention of researchs on anion exchange and intercalation but very limited numbers of reports have been published on their synthesis, characteristics, and application. This study reports basic properties of a layered copper hyroxide acetate synthesized by a method modified from that of the previous studies. Titration of copper acetate solution with a dilute NaOH solution to pH 6.5 and subsequent aging at 313 K yielded a layered copper hydroxide acetate. This compound has some properties similar to those of the previously known copper hydroxide acetate, Cu₂(OH)₃(OCOCH₃)H₂O. The present copper hydroxide acetate is dissimilar to the previous compound in morphology, stability of bonding between the interlayer acetate ions and the matrix hydroxides, and reaction with anions in aqueous solutions.

34000087
Retention characteristics of hydrogen isotopes in JT-60U
Masaki, Kei; Sugiyama, Kazuyoshi*; Hayashi, Takao; Ochiai, Kentaro; Goto, Yoshitaka*; Shibahara, Takahiro*; Hirohata, Yuko*; Oya, Yasuhisa*; Miya, Naoyuki; Tanabe, Tetsuo*
Journal of Nuclear Materials 337-339, p.553-559(2005) ; (JAEA-J 00236)

34000088
Incident energy dependence of blistering at tungsten irradiated by low energy high flux deuterium plasma beams
Luo, G.; Shu, Wataru; Nishi, Masataka
Journal of Nuclear Materials 347(1-2), p.111-117(2005) ; (JAEA-J 00237)

Polycrystalline tungsten samples have been irradiated at room temperature by high flux (1×10²² D/m²/s) deuterium plasma beams with incident energies ranging 7 ~ 98 eV/D. Surface blistering occurred at all energies. The critical fluence for blistering Φ_cr was found to increase with decreasing the incident energy. At energies < 20 eV/D, Φ_cr increased more rapidly. This energy dependence of Φ_cr may be explained by a proposed model dealing with the oxide barrier to deuterium uptake into and release from the bulk W. At all energies, the blisters increased in their size and number with fluence within the corresponding low fluence ranges. However the size stopped increasing at certain fluences, while the number kept increasing within the experimental fluence range, which could be attributed to rupturing of blisters at a certain size of about 2μm.

34000089
Radiochemical studies of the transactinide element, rutherfordium (Rf) at JAERI
Nagame, Yuichiro
Journal of Nuclear and Radiochemical Sciences 6(2), p.A21-A28(2005) ; (JAEA-J 00238)

34000090
Development of EC launcher components for ITER
Takahashi, Koji; Kobayashi, Noriyuki*; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Physics: Conference Series 25, p.75-83(2005) ; (JAEA-J 00239)

Recent progress of the development on the ITER equatorial EC launcher components, such as the steering mirrors, its drive system, the waveguide components and the diamond vacuum windows, is reported. Thermmo-mechanical analysis of the recent mirror design shows that maximum temperature increase of 187^°C at the reflecting surface and maximum stress of 242MPa at the inner surface of the cooling tube are obtained. In the cyclic test of the spiral tube mock-up, the cyclic number of 1.3×10⁶ is succeeded without failure. In the window development, the fabrication of the Cu-coated edge diamond window and the high power transmission test were done. The Cu-coating on the disk edge can avoid water ingress in the launcher (vessel) under the assumption of the crack formation toward edge. Transmission experiment indicative to 1.2MW, was carried out. Temperature increase of 50^°C agrees with the calculation. It concludes that the Cu-coated window is capable of MW-level transmission and improves its reliability.

34000091
Electron density behavior during fast termination phase of post-disruption runaway plasma
Kawano, Yasunori; Nakano, Tomohide; Asakura, Nobuyuki; Tamai, Hiroshi; Isayama, Akihiko; Kondoh, Takashi; Hatae, Takaki; Takenaga, Hidenobu; Ide, Shunsuke
Journal of Plasma and Fusion Research 81(10), p.743-744(2005) ; (JAEA-J 00240)

Electron density of post-disruption runaway plasmas in JT-60U has been measured by the tangential CO₂ laser interferometer. Increases in electron density after the first drop of runaway plasma current have been observed during a fast termination phase of the runaway plasma. At the second current drop, an increase in electron density with multiple spikes or oscillation with the period of 1 ms has been found. It is suggested that the increased electron density seems to take part in the shorter current decay time after the second current drop.

34000092
Development of a heat-resistant neutron shielding resin for the national centralized tokamak
Morioka, Atsuhiko; Sakurai, Shinji; Okuno, Koichi*; Tamai, Hiroshi
Journal of Plasma and Fusion Research 81(9), p.645-646(2005) ; (JAEA-J 00241)

A 300 ^°C heat-resistant neutron shielding material is newly developed, which consists of phenol-based resin with 5 weight-% boron. The neutron shielding performance of the developed resin, examined by the ²⁵²Cf neutron source, is almost the same as that of the polyethylene. The resin is applicable to the port section of vacuum vessel of the DD plasma device to suppress the streaming neutrons and to reduce the nuclear heating of the superconducting coils.

34000093
Single crystal growth and fermi surface properties of ThIn₃
Matsuda, Tatsuma; Haga, Yoshinori; Ikeda, Shugo; Shishido, Hiroaki*; Settai, Rikio*; Harima, Hisatomo*; Onuki, Yoshichika
Journal of the Physical Society of Japan 74(12), p.3276-3282(2005) ; (JAEA-J 00242)

We have succeeded in growing a high-quality single crystal of ThIn₃ with the cubic structure by the In-flux method and measured the electrical resistivity, magnetic susceptibility and de Haas-van Alphen (dHvA) effect. Several dHvA branches were observed, ranging from 5.2 × 10⁶ to 1.7 × 10⁸ Oe. The Fermi surface consists of a nearly spherical Fermi surface and a multiply-connected Fermi surface with many but small extremal cross-sections. The corresponding cyclotron effective masses are small, ranging from 0.31 to 1.4 m₀. These Fermi surface properties are well explained by the energy band calculations based on the FLAPW method.

34000094
Overview of JT-60U progress towards steady-state advanced tokamak
Ide, Shunsuke; JT-60 Team
Nuclear Fusion 45(10), p.S48-S62(2005) ; (JAEA-J 00243)

34000095
Nonlinear behaviour of collisionless double tearing mode induced by electron inertia
Matsumoto, Taro; Naito, Hiroshi*; Tokuda, Shinji; Kishimoto, Yasuaki*
Nuclear Fusion 45(11), p.1264-1270(2005) ; (JAEA-J 00244)

A gyrokinetic particle simulation is executed to clarify the effect of the electron inertia on the MHD phenomena in the reversed shear configuration (RSC) of a cylindrical tokamak plasma. It is found that the collisionless (kinetic) double tearing modes grow up at the Alfv'en time scale, and nonlinearly induce the internal collapse when the helical flux at the magnetic axis is less than that at the outer resonant surface. After the internal collapse, the secondary reconnection is induced by the current concentration due to the m=2 convective flow. It is also clarified that a nonlinear dynamics accompanied with the elementary processes caused by the m=2 flow can generate a new RSC with resonant surfaces. In the presence of the density gradient, after the full reconnection induced by the m=2 mode, the radial electric field is found to be generated due to the difference of the E × B motion between ions and electrons. However, the intensity of the radial field is not so large as that induced by the collisionless kink mode.

34000096
Development of advanced superconducting coil technologies for the National Centralized Tokamak
Kizu, Kaname; Miura, Yushi*; Tsuchiya, Katsuhiko; Ando, Toshinari*; Koizumi, Norikiyo; Matsui, Kunihiro*; Sakasai, Akira; Tamai, Hiroshi; Matsukawa, Makoto; Ishida, Shinichi; Okuno, Kiyoshi
Nuclear Fusion 45(11), p.1302-1308(2005) ; (JAEA-J 00245)

34000097
Advanced tokamak research on JT-60
Kishimoto, Hiroshi; Ishida, Shinichi; Kikuchi, Mitsuru; Ninomiya, Hiromasa
Nuclear Fusion 45(8), p.986-1023(2005) ; (JAEA-J 00246)

The Japanese large tokamak JT-60 has been focusing its research emphases to develop a high performance plasma, namely high confinement, high temperature and high density, and to sustain it non-inductively for a long time with possible minimization of external power input. The first demonstration of high bootstrap current discharges in a high-poloidal-beta mode (high-βp) and the concept development of a steady-state tokamak reactor SSTR based on this experimental achievement initiated the so-called "advanced tokamak research". The first observation of internal transport barriers in the JT-60 high-βp mode was followed by the world-wide explorations of reversed shear discharges associated with internal transport barriers. The advanced tokamak research is now the major trend of the current tokamak development. A new concept of compact ITER was developed and proposed in the context of this advanced tokamak approach pursued on JT-60.

34000098
Recrystallization behavior in SiC amorphized with He or Ne irradiation
Aihara, Jun; Hojo, Tomohiro*; Furuno, Shigemi*; Ishihara, Masahiro; Sawa, Kazuhiro; Yamamoto, Hiroyuki; Hojo, Kiichi
Nuclear Instruments and Methods in Physics Research B 241(1-4), p.559-562(2005) ; (JAEA-J 00247)

Silicon carbide (SiC) specimens prepared for the TEM (transmission electron microscope) observation were amorphized with 30keV Ne or 4.5keV He ion irradiation at room temperature and successively annealed at 1273K in the TEM. Ne and He were selected as irradiation ion species to change the concentration of implanted rare gas atoms. The energy and flux of these ion species were selected in order to get similar dpa depth profiles and dpa rates based on TRIM calculation. In this condition, peak ion implantation of He was estimated to be about 5 times as large as that of Ne for the same peak dpa. Crystal nucleation occurred with annealing in the specimen irradiated with He up to 6.3dpa(peak), however, no crystal nucleation was observed in the specimen irradiated with Ne up to 15dpa(peak); Namely, crystal nucleation occurred with less dpa in the case of He irradiation than in the case of Ne irradiation. It was found that the concentration of implanted inert gas atom influences the crystal nucleation behavior.

34000099
Microstructural change with annealing of SiC irradiated with Ne at 573-673 K
Aihara, Jun; Hojo, Kiichi; Furuno, Shigemi*; Shimura, Kenichiro; Hojo, Tomohiro*; Sawa, Kazuhiro; Yamamoto, Hiroyuki; Motohashi, Yoshinobu*
Nuclear Instruments and Methods in Physics Research B 242(1-2), p.441-444(2006) ; (JAEA-J 00248)

34000100
Photoluminescence of β-FeSi₂ thin film prepared by ion beam sputter deposition method
Shimura, Kenichiro; Yamaguchi, Kenji; Yamamoto, Hiroyuki; Sasase, Masato*; Shamoto, Shinichi; Hojo, Kiichi
Nuclear Instruments and Methods in Physics Research B 242(1-2), p.673-675(2006) ; (JAEA-J 00249)

34000101
Modification of thin SIMOX film into β-FeSi₂ via dry processes
Shimura, Kenichiro; Yamaguchi, Kenji; Sasase, Masato*; Yamamoto, Hiroyuki; Shamoto, Shinichi; Hojo, Kiichi
Nuclear Instruments and Methods in Physics Research B 242(1-2), p.676-678(2006) ; (JAEA-J 00250)

34000102
Resonant inelastic X-ray scattering study of overdoped La_2-xSr_xCuO₄
Wakimoto, Shuichi; Kim, Y.-J.*; Kim, H.*; Zhang, H.*; Gog, T.*; Birgeneau, R. J.*
Physical Review B 72(22), p.224508_1-224508_7(2005) ; (JAEA-J 00251)

Resonant inelastic X-ray scattering (RIXS) at the copper Kabsorption edge has been performed for heavily overdoped samplesof La_2-xSr_xCuO₄ with x= 0.25 and 0.30. We have observed the chargetransfer and molecular orbital excitations which exhibit resonances at incident energies of E_i= 8.992 and 8.998~keV,respectively. From a comparison with previous results on undoped andoptimally-doped samples, we determine that the charge transfer excitation energy increases monotonically as doping increases. In addition, the E_i-dependences of the RIXS spectral weight and absorption spectrum exhibit no clear peak at E_i = 8.998~keV in contrast to results in the underdoped samples. The low-energy (< 3~eV) continuum excitation intensity has been studied utilizing the high energy resolution of 0.13~eV (FWHM). A comparison of the RIXS profiles at (π ~0) and (π ~π) indicates that the continuum intensity exists even at (π ~π) in the overdoped samples, while it has been reported only at (0 ~0) and (π ~0) for the x=0.17 sample. Furthermore, we also found an additional excitation on top of the continuum intensity at the (π ~π) and (π ~0) positions.

34000103
Is a global coupled-channel dispersive optical model potential for actinides feasible?
Capote, R.*; Soukhovitskij, E. Sh.*; Quesada, J. M.*; Chiba, Satoshi
Physical Review C 72(6), p.064610_1-064610_6(2005) ; (JAEA-J 00252)

34000104
Experimental identification of spin-parities and single-particle configurations in ²⁵⁷No and its α-decay daughter ²⁵³Fm
Asai, Masato; Tsukada, Kazuaki; Sakama, Minoru*; Ichikawa, Shinichi; Ishii, Tetsuro; Nagame, Yuichiro; Nishinaka, Ichiro; Akiyama, Kazuhiko; Osa, Akihiko; Oura, Yasuji*; Sueki, Keisuke*; Shibata, Michihiro*
Physical Review Letters 95(10), p.102502_1-102502_4(2005) ; (JAEA-J 00253)

Excited states in ²⁵³Fm fed by the α decay of ²⁵⁷No have been established through α-γ and α-electron coincidence spectroscopy using a gas-jet transport system and an on-line isotope separator. The spin-parity of the 124.1 keV level in ²⁵³Fm has been identified on the basis of the measured internal conversion coefficients. The ν 3/2⁺[622] configuration has been assigned to the ground state of ²⁵⁷No as well as to the 124.1 keV level. It was found that the ground state configuration of ²⁵⁷No is different from that of lighter N=155 isotones.

34000105
Analytical solution for phase space evolution of electrons operating in a self-amplified spontaneous emission free electron laser
Nishimori, Nobuyuki
Physical Review Special Topics; Accelerators and Beams 8(10), p.100701_1-100701_9(2005) ; (JAEA-J 00254)

I present an analytical solution for the phase space evolution of electrons in a self-amplified spontaneous emission (SASE) Free Electron Laser (FEL) operating in the linear regime before saturation in the resonant case by solving the one dimensional FEL equation together with the solution of the cubic equation, which represents the evolution of the SASE FEL field. The electrons are shown to be bunched around pi/6 ahead of a resonant electron every resonant FEL wavelength in the high gain regime. The phase relation is similar to that in a low gain FEL where an electron beam above resonance is injected, explaining the positive FEL gain. The analytical solutions agree well with numerical simulations and are applied to obtain the coherent optical transition radiation (OTR) intensity produced from electron microbunching at FEL wavelength. The coherent OTR intensity is shown to be proportional to FEL intensity.

34000106
Feasibility of beam crystallization in a cooler storage ring
Yuri, Yosuke; Okamoto, Hiromi*
Physical Review Special Topics; Accelerators and Beams 8(11), p.114201_1-114201_12(2005) ; (JAEA-J 00255)

It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an "ordered" configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments.It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

34000107
Laser polarization dependence of proton emission from a thin foil target irradiated by a 70 fs, intense laser pulse
Fukumi, Atsushi*; Takai, Mamiko; Daido, Hiroyuki; Li, Z.*; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Kado, Masataka; Hayashi, Yukio; Mori, Michiaki; Bulanov, S. V.; Esirkepov, T. Z.; Nemoto, Koshichi*; Oishi, Yuji*; Nayuki, Takuya*; Fujii, Takashi*; Noda, Akira*; Nakamura, Shu
Physics of Plasmas 12(10), p.100701_1-100701_4(2005) ; (JAEA-J 00256)

A study of proton emission from a 3-μm thick Ta foil target irradiated byp-, s- and circularly polarized laser pulses with respect to the targetplane has been carried out.Protons with energies up to 880 keV were observed in the target normaldirection under the irradiation by the p-polarized laser pulse, which yieldedthe highest efficiency for proton emission. In contrast, s- and circularlypolarized laser pulses gave the maximum energies of 610 keV and 680 keV,respectively. The difference in the maximum energy between the p- ands-polarized cases was associated with the difference between thesheath fields estimated from electron spectra.

34000108
Study on the etching conditions of polycarbonate detectors for particle analysis of safeguards environmental samples
Iguchi, Kazunari; Esaka, Konomi; Lee, C. G.; Inagawa, Jun; Esaka, Fumitaka; Onodera, Takashi; Fukuyama, Hiroyasu; Suzuki, Daisuke; Sakurai, Satoshi; Watanabe, Kazuo; Usuda, Shigekazu
Radiation Measurements 40(2-6), p.363-366(2005) ; (JAEA-J 00257)

In particle analysis for safeguards environmental samples, the fission track technique is very important to detect sub-micrometer particles containing uranium. In the technique the authors developed, the particles were recovered onto the polycarbonate membrane filter. The filter was dissolved in solvent and dried to form a thin film of detector, in which the particles were confined. After thermal neutron irradiation and etching, the particles of interest in the detector were easily identified with fission tracks, and were picked up for isotope ratio analysis. It was found, however, that the particles in the vicinity of the detector surface may fall off during the etching process. Therefore, optimization of the etching condition is required. In this work, the effects of etching time and enrichment of uranium in particles were investigated. Preliminary results suggest that etching time should be shorter with the increase in the enrichment.

34000109
Electrochemical and spectroelectrochemical behaviour of Np(VI) ions in nitric acid solutions
Kim, S.-Y.; Asakura, Toshihide; Morita, Yasuji
Radiochimica Acta 93(12), p.767-770(2005) ; (JAEA-J 00258)

Electrochemical and spectroelectrochemical has been used to investigate the behaviour of Neptunium (VI) in concentration 1-8 M HNO₃ solutions. The electrochemical reactions of Np(VI) ions were found to occur quasi-reversibly. The formal redox potentials (E^°) for Np(VI)/Np(V) couples were determined to be +0.906, +0.908, +0.909, +0.902, +0.896, +0.895, +0.888, and +0.884 V (vs. Ag/AgCl) for Np(VI) ions in 1, 2, 3, 4, 5, 6, 7, 8 M HNO₃ solutions, respectively. The reduction processes of Np(VI) ions were followed spectroelectrochemically by using an optical transparent thin layer electrode cell. It was found that the absorption spectra measured at the applied potentials from +1.10 to +0.60 V versus Ag/AgCl reference electrode redox couple for Np(VI) in HNO₃ solution have clear isosbestic points. These results indicate that the reduction product of Np(VI) is Np(V), which is considerably stable in HNO₃ solution.

34000110
Current status of phantom use in atomic energy feild and problem for standardization (in Japanese)
Kurihara, Osamu
FBNews (349), p.7-11(2006) ; (JAEA-J 00259)

34000111
Surface chemical reaction dynamics illuminated by high brilliance and high energy-resolution synchrotron radiation; In-situ photoemission spectroscopy for surface oxidation induced by supersonic O₂ molecular beams (in Japanese)
Teraoka, Yuden; Yoshigoe, Akitaka; Moritani, Kosuke; Takakuwa, Yuji*; Ogawa, Shuichi*; Ishizuka, Shinji*; Okada, Michio*; Fukuyama, Tetsuya*; Kasai, Toshio*
Hoshako 18(5), p.298-309(2005) ; (JAEA-J 00260)

Representative research results in surface reaction dynamics, performed at a surface chemistry experimental station installed in the JAEA soft X-ray beamline in the SPring-8, were reviewed. As a research result in JAEA, SiO desorption mechanisms in the Si(001) oxidation at high temperature were introduced. As a collaboration with Osaka University on oxidation reaction dynamics of Cu, collision-induced atom absorption process was introduced. As a collaboration with Tohoku University on Ti(0001) oxidation reaction dynamics, it was introduced that two peaks, found in an incident energy dependence of initial sticking probability, were corresponding to potential energy barriers of dissociative adsorption of O₂ molecules.

34000112
Soft X-ray circular dichroism of biomolecules (in Japanese)
Nakagawa, Kazumichi*; Tanaka, Masahito*; Agui, Akane
Hoshako 18(6), p.363-372(2005) ; (JAEA-J 00261)

34000113
Recent progress on solution chemistry of actinides studied by time-resolved laser-induced fluorescence spectroscopy (in Japanese)
Kimura, Takaumi; Kirishima, Akira*; Arisaka, Makoto
Kidorui (47), p.43-56(2005) ; (JAEA-J 00262)

34000114
Electronic excitations in strongly correlated electron systems studied by resonant inelastic X-ray scattering (in Japanese)
Ishii, Kenji
Hoshako 18(6), p.347-355(2005) ; (JAEA-J 00264)

Strongly correlated electron systems are one of the most important issue in modern solid state physics, because they show interesting phenomena such as high-T_c superconductivity and colossal magnetoresistance. Resonant inelastic X-ray scattering (RIXS) technique in the hard X-ray regime has been developed to clarify their electronic structure. Our recent RIXS studies on metallic manganites and cuprates are described. The excitation across the Mott gap is observed even in the metallic phase and the electron correlation effect persists in the carrier-doped Mott insulators. In addition to the Mott gap excitation, the dispersion relation of the intraband excitation in the upper Hubbard band is successfully observed in the electron-doped cuprates.

34000115
Characteristics of ²²²Rn measurement with a gas-filled ionization chamber (in Japanese)
Ishimori, Yu
Radioisotopes 54(12), p.599-608(2005) ; (JAEA-J 00266)

The radon measurement with a gas-filled ionization chamber is generally performed at many laboratories in Japan as a standard method. In this paper, the characteristics of the method have been examined as follows. The wall effects against the different filled gases, nitrogen and dry air, have been evaluated with Monte Carlo simulation. The columnar recombination has been also evaluated from two different ways; one is the common evaluation from the relationship between inverse of ionization current and inverse of applied voltage; another is the evaluation from the relationship between the ionization current in the different gas pressure and the wall effect expected in each pressure. Both results have been agreed with each other. As the total, the efficiencies of ionization chamber, volume of which is 1.5L, are estimated to be 0.02706 Bq.fA^-1 for nitrogen gas of 93.3kPa and 0.02701Bq.fA^-1 for air of 101.3kPa, and the values are very close to the conversion factor on the literatures within 3% of difference. Furthermore the effect by humidity has been preliminarily estimated, and the effect is almost -3% per 1% of absolute humidity but it can be easily removed by the suitable dryer. These examinations have proven the method with a gas-filled ionization chamber has high accuracy for radon measurement. An ²⁴¹Am disk source was used with same methods to confirm the results above mentioned.

34000116
Development of public dose assessment code for decommissioning of nuclear reactors (DecDose)
Shimada, Taro; Oshima, Soichiro; Ishigami, Tsutomu; Yanagihara, Satoshi
Proceedings of 10th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM '05) (CD-ROM) , 8p.(2005) ; (JAEA-J 00267)

In order to review an operator's "Decommissioning Plan" applied to the regulatory body for approval accurately and quickly, Public Dose Assessment Code for Decommissioning of Nuclear Reactors (DecDose) was developed. It evaluates public exposure doses for each year during dismantling activities in accordance with the "Decommissioning Plan". DecDose takes account of various exposure pathways such as cloudshine, surface ground deposition, ingestion of seafood, and direct and skyshine radiation based on the quantity of radionuclides discharged to the environment, and containers stored in the facility in consideration of cutting and storage of components and structures. Example evaluations with DecDose have shown that it is a useful tool for assessing public dose during decommissioning of nuclear reactors.

34000117
Rationalization of the fuel integrity and transient criteria for the super LWR
Yamaji, Akifumi*; Oka, Yoshiaki*; Ishiwatari, Yuki*; Liu, J.*; Koshizuka, Seiichi*; Suzuki, Motoe
Proceedings of 2005 International Congress on Advances in Nuclear Power Plants (ICAPP '05) (CD-ROM) , 7p.(2005) ; (JAEA-J 00268)

Ensuring the fuel integrities is one of the most fundamental parts in the High Temperature Supercritical-Pressure Light Water Reactor. Most abnormal transient events of SCLWR-H last for a short period of time and the fuel rods are replaced after being irradiated in the core. In this study, the fuel integrity criteria are rationalized based on the fact that the fuel rod mechanical failures can be represented by the strain of the fuel rod cladding. A new fuel rod is designed with a Stainless Steel cladding. It is internally pressurized to reduce the stress on the cladding and also to increase the gap conductance between the pellet and the cladding. The fuel integrities both at normal operation and abnormal transient conditions are evaluated using the fuel analysis code FEMAXI-6 of JAERI.

34000118
Japanese underground research laboratory project and prediction of rock mass behavior around deep shafts and galleries using continuous and discontinuous models
Sato, Toshinori; Mikake, Shinichiro; Nakama, Shigeo; Seno, Yasuhiro; Mori, Takayuki*; Iwano, Keita*; Goke, Mitsuo*; Tada, Hiroyuki*
Proceedings of 7th International Conference on Analysis of Discontinuous Deformations (ICADD-7) (CD-ROM) , p.245-256(2005) ; (JAEA-J 00269)

Two one-thousand meter deep shafts and research galleries at several levels will be excavated in granite for the Mizunami Underground Research Laboratory(MIU) Project. Research on the deep geological environment in this project will provide the basis for Research and Development on geological disposal of high-level radioactive waste. The site of MIU project is located in Mizunami, Gifu, in the central part of the main island of Japan. By July 2003, entrances to the shafts were constructed, and excavation of lower part of shaft entrance was started in March 2004. Current status(September 2005) of construction is excavation of the shafts to a depth of 150 m has been done. Mechanical investigations including hydraulic fracturing test and laboratory tests on core samples were performed, and numerical analysis using continuous model and discontinuous model; MBC(Micro-mechanics based continuum model), Crack tensor model and FRACOD(fracture propagation code), were also performed to predict mechanical stability of openings and support systems, and rock mass behavior around openings. In this analysis EDZ(Excavation Damaged Zone) due to blasting and excavation step were considered in same cases. This paper describes the current status of Mizunami Underground Research Laboratory for crystalline rock and the results of prediction for rock mass behavior around the deep underground openings using some analytical methods. Measurements during shaft sinking and future plan of investigations in the URL are also describes in this paper.

34000119
Experiments on the behavior of americium in pyrochemical process
Hayashi, Hirokazu; Akabori, Mitsuo; Minato, Kazuo
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM) , 3p.(2005) ; (JAEA-J 00270)

For a basis of the future nuclear cycle, it is very important to understand and control the behavior of TRU (Np, Pu, Am, Cm) in the nuclear fuel cycle. Experimental study of pyrochemical process of fuels containing TRU requires the facility having not only shielding for γ-ray and neutron but also ability to keep a high purity inert gas atmosphere; because minor actinide chlorides can easily react with oxygen or water vapor in an atmosphere. The module for TRU high temperature chemistry (TRU-HITEC) had been installed to study the basic properties of TRU in the pyrochemical processes. In the present work, the behavior of ²⁴¹Am in pyrochemical process was investigated by electrochemical methods.

34000120
Wind-wave-surge coupled model; Application to storm surge simulation in the bay of Bengal
Kim, K.; Yamashita, Takao*
Proceedings of International Symposium on Fluvial and Coastal Disasters (CD-ROM) , 8p.(2005) ; (JAEA-J 00271)

Authors developed the wind-wave-surge coupled numerical model for storm surge simulation and made clear its availability for storm surges in the extremely shallow water. The developed model consists of the meso-scale atmospheric circulation models (MM5), ocean wave model (WW3) and ocean circulation model (POM). An additional sea surface stress, the whitecap wave breaking stress, was introduced in the model to consider the processes of energy transfer from wind to current through whitecap breaking. The conducted hindcast of storm surge in this study clearly showed the importance of energy transfer path via whitecap dissipation of wind waves in the generation mechanism of mean current in the extremely shallow water. This model was applied to the simulation of storm surges and waves in the Bay of Bengal for the cyclone in 1991. The importance of wave effects on wind-induced current fields in the extremely shallow water was also made clear in this research.

34000121
Specific absorbed fractions for photon and electron to a simple stomach model considering stem cells
Kinase, Sakae; Yokoya, Ritsuko; Saito, Kimiaki
KEK Proceedings 2005-10 (CD-ROM) , p.33-38(2005) ; (JAEA-J 00273)

The aim of the present work has been the development of logical dosimetry for human alimentary tract. In this work, a stomach simple model with stem cells has been developed. Also, specific absorbed fractions for photon and electron to the stomach model have been evaluated in the energy range 10 keV-4MeV using Monte Calro simulation. Consequently, it was found that photon SAFs to the stem cell in the stomach are more than those to the stomach wall. Electron SAFs to the stem cell in the stomach were also found to be less than that used in the radiological protection. It is concluded that the Monte Carlo simulation is very useful in the development of logical dosimetry for the stomach and that the determination of target tissue in the stomach is very important for the SAF evaluation.

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JAEA > JAEA Library > JOPSS > Papers Published in Journals [Back Issues] > February 2006