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ScZidarova, R.*; Utsuno, Yutaka; 76 of others*
Physica Scripta, 99(7), p.075309_1 - 075309_9, 2024/06
Times Cited Count：0 Percentile：0.00(Physics, Multidisciplinary)no abstracts in English
Daido, Hiroyuki*; Yamada, Tomonori; Saruta, Koichi; Miyabe, Masabumi; Ito, Chikara; Shibata, Takuya; Inoue, Kaoru*; Terabayashi, Ryohei*; Hasegawa, Shuichi*
Physica Scripta, 98(3), p.035112_1 - 035112_22, 2023/02
Times Cited Count：0 Percentile：0.00(Physics, Multidisciplinary)Characterization of kW class quasi-continuous wave (a pulse duration of 10 ms) laser interaction with metal targets and those with metal oxide targets are presented in respect to the laser induced breakdown and the successive laser induced melting and evaporation coupled with a mechanical response followed by ejection of various kinds of particles and fragments. An experiment was performed using fiber lasers coupled with a high-speed camera to observe dynamics of the interaction. Ejected fine particles were collected using a cascade impactor and a home-made collector and were observed with electron microscopes. Shapes of irradiation marks were observed with a digital optical microscope. We also measured total ejected mass from a target. The experimental results reveal that firstly the laser threshold intensity of the interaction with the metal target was lower and more stable than those with the metal oxide targets. Secondly, in the stainless steel targets, the dynamics of molten layer created by thermal conduction from the laser heated thin layer and successive particle ejection with less mechanical response by the adjacent solid layer are dominant processes, while in the metal oxide targets, the fracturing in the relatively deeper interaction region coupled with brittle material response having relatively large laser shot to shot fluctuation appears to play a significant role in addition to the laser induced melting.
Shimizu, Noritaka*; Abe, Takashi*; Homma, Michio*; Otsuka, Takaharu*; Togashi, Tomoaki*; Tsunoda, Yusuke*; Utsuno, Yutaka; Yoshida, Toru*
Physica Scripta, 92(6), p.063001_1 - 063001_19, 2017/06
Times Cited Count：31 Percentile：82.61(Physics, Multidisciplinary)no abstracts in English
Fujita, Hiroe*; Yuyama, Kenta*; Li, X.*; Hatano, Yuji*; Toyama, Takeshi*; Ota, Masayuki; Ochiai, Kentaro; Yoshida, Naoaki*; Chikada, Takumi*; Oya, Yasuhisa*
Physica Scripta, 2016(T167), p.014068_1 - 014068_5, 2016/02
Times Cited Count：34 Percentile：82.88(Physics, Multidisciplinary)The irradiation defects were introduced by Fe
irradiation, fission neutron irradiation and D-T neutron irradiation. After the irradiation, the deuterium ions (D
) implantation was performed and the D retention behavior was evaluated by thermal desorption spectroscopy. The experimental results indicated that dense vacancies and voids within the shallow region near the surface were introduced by Fe irradiation. The trapping state of D by vacancies and void were clearly controlled by the damage concentration and the voids would become the most stable D trapping site. For fission neutron irradiated W, most of the D was adsorbed on the surface and/or trapped by dislocation loops and no vacancies and voids for D trapping due to its lower damage concentration. D trapping by vacancies were found in the bulk of D-T neutron irradiated W, indicating that the neutron energy distribution could make a large impact on irradiation defect formation and the D retention behavior.
Moribayashi, Kengo
Physica Scripta, 90(5), p.054013_1 - 054013_5, 2015/05
Times Cited Count：5 Percentile：38.75(Physics, Multidisciplinary)
H, NH and OH clusters induced by irradiation with X-ray free electron lasersKai, Takeshi
Physica Scripta, T144, p.014050_1 - 014050_4, 2011/06
Times Cited Count：2 Percentile：19.66(Physics, Multidisciplinary)Moribayashi, Kengo
Physica Scripta, T144, p.014049_1 - 014049_3, 2011/06
Times Cited Count：2 Percentile：19.66(Physics, Multidisciplinary)We will soon get new X-ray sources, that is, X-ray free electron lasers (XFELs) which will be developed in USE, EU, and Japan around 2010. If we can use them well, it will bring useful fruits for the man's future. We predict that these high-intensity short-wavelength X-ray sources provide new physical phenomena and that they give rise to new technologies. In this paper, we show the mechanism of the production of hollow atoms and the behavior of photo-electrons produced by high intensity X-rays irradiating a cluster or a bio-molecule. We have also proposed the X-ray flux by using them.
Suzuki, Satoshi; Ezato, Koichiro; Seki, Yohji; Yokoyama, Kenji; Hirose, Takanori; Mori, Seiji; Enoeda, Mikio
Physica Scripta, T138, p.014003_1 - 014003_5, 2009/12
Times Cited Count：3 Percentile：25.72(Physics, Multidisciplinary)JAEA is going to procure the whole ITER divertor outer vertical target. The qualification of the ITER divertor components has been started to validate the technical capability of the domestic agencies. JAEA has developed vertical target qualification prototypes which cover most of the critical technical issues toward the series of production. The prototypes have been high heat flux tested in Efremov institute, and showed sufficient durability at 20 MW/m
. JAEA has successfully obtained the certification from ITER organization. Development of a breeding blanket is one of the most important issues to realize DEMO plant. The engineering testing of the Test Blanket Module (TBM) in ITER is a key milestone toward the DEMO blanket. R&D's on the water-cooled solid breeder blanket has been performed in JAEA. A full-scale length TBM first wall mock-up made of F82H, has been developed by using HIP bonding technique. This mock-up showed sound thermal performance in the high heat flux test.
Alimov, V.; Shu, Wataru*; Roth, J.*; Sugiyama, Kazuyoshi*; Lindig, S.*; Balden, M.*; Isobe, Kanetsugu; Yamanishi, Toshihiko
Physica Scripta, T138, p.014048_1 - 014048_5, 2009/12
Times Cited Count：128 Percentile：95.20(Physics, Multidisciplinary)Blistering and deuterium retention in re-crystallized tungsten exposed to low-energy, high flux (10
D/ms) pure and helium-seeded D plasmas to a fluence of 10
D/m have been examined with scanning electron microscopy, thermal desorption spectroscopy (TDS), and the D(
He,p)
He nuclear reaction at a He energy varied from 0.69 to 4.0 MeV. In the case of exposure to pure D plasma (38 eV/D), blisters with various shapes and sizes depending on the exposure temperature are found on the W surface. No blisters appear at temperatures above 700 K. The deuterium retention increases with the exposure temperature, reaching a maximum value of about 10 D/m at 480 K, and then decreases as the temperature rises further. Seeding of helium into the D plasma to the He ion concentration of 0.2 and 5% significantly reduces the D retention at elevated temperatures and prevents formation of the blisters.
Colgan, J.*; Abdallah, J. Jr.*; Faenov, A. Y.; Pikuz, T. A.*; Skobelev, I. Yu.*
Physica Scripta, 78(1), p.015302_1 - 015302_6, 2008/07
Times Cited Count：10 Percentile：54.85(Physics, Multidisciplinary)Shu, Wataru; Kawasuso, Atsuo; Miwa, Yukio; Wakai, Eiichi; Luo, G.-N.*; Yamanishi, Toshihiko
Physica Scripta, T128, p.96 - 99, 2007/03
Times Cited Count：95 Percentile：92.20(Physics, Multidisciplinary)The dependence of deuterium retention and blistering upon the microstructures of tungsten exposed to 38 eV plasma were studied with TDS, PA and SEM. For samples exposed to higher fluences (up to 10 D/m
), a peculiar phenomenon of bursting release of deuterium was found obviously in TDS spectra, where sudden spikes appeared. SEM observations also confirmed the phenomenon of bursting of blisters, even for the single crystal tungsten (111) exposed to 10
D/m at room temperature. The preliminary PA measurements suggested that the vacancy concentration in the near-surface region of the partially-recrystallized tungsten increased after the exposure, and electron back-scattering diffraction (EBSD) results showed that blisters appeared predominantly on the grains with nearly (111) surface orientation.
Agui, Akane; Mizumaki, Masaichiro*; Matsushita, Tomohiro*; Kawamura, Naomi*; Nakatani, Takeshi
Physica Scripta, T115, p.611 - 613, 2005/00
no abstracts in English
Tanaka, Masahito*; Nakagawa, Kazumichi*; Agui, Akane; Fujii, Kentaro; Yokoya, Akinari
Physica Scripta, T115, p.873 - 876, 2005/00
no abstracts in English
Mizumaki, Masaichiro*; Yoshii, Kenji; Hinatsu, Yukio*; Doi, Yoshihiro*; Uruga, Tomoya*
Physica Scripta, T115, p.513 - 515, 2005/00
The electronic and structural properties of Ru oxides were investigated by utilizing X-ray absorption spectroscopy (XAS). We estimate the valence of Ru in perovskite ruthenium oxides by XAS measurements. XAS measurements were carried out at room temperature around Ru K-edge. The valence of Ru in 
( = Ba, Sr)LnRuO
and ( = Ca, Ba, Sr)RuO
was 4+. The valence of Ru in LnRuO
was 5+. The valence of Ru in PbRuO showed an intermediate value between 4+ and 5+. Theoretical calculation reproduced the experimental spectra. We analyzed XAS spectra and obtained information of local structure. The bond length between Ru and O was consistent with the results of neutron diffraction.
Yoneda, Yasuhiro; Matsumoto, Norimasa; Furukawa, Yukito*; Ishikawa, Tetsuya*
Physica Scripta, T115, p.995 - 997, 2005/00
Sagittal focusing is known as one of the most efficient focusing methods for synchrotron X-rays which increases the photon density at the sample position. Results are reported on the performance of a fixed height exit bender with an unribbed silicon (311) crystal. The fixed height exit was achieved by using a 4-point bending mechanism. This bending mechanism is designed for the SPring-8 standard double crystal monochromator (DCM) of bending-magnet beamlines and the bender is installed as a second crystal of the DCM. By using unribbed crystal, the focusing beam size was kept 0.5 mm in the energy ranges from 35 - 60 keV. Since mirrors for high-energy X-rays are still under development at the moment, focusing techniques by crystal bender are demanded for many practical applications.
Yaita, Tsuyoshi; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro; Shimada, Asako*; Assefa, Z.*; Haire, R. G.*
Physica Scripta, T115, p.302 - 305, 2005/00
The structural parameter and the electronic structure of the complex between cerium and N,N'-dimethyl-N,N'-diphenylpyridine-2,6-carboxyamide(DMDPhPDA) was investigated by XAFS, photo luminescence and excitation spectra. The DMDPhPDA is one of the promising ligands for separation of trivalent actinides from lanthanides. The Ce-K XAFS spectra were measured at BL11XU of SPring-8. The bond distances between the carbonyl oxygens and cerium, and between the pyridyl nitrogen and cerium are 253pm and 264pm, respectively. The bond angle of the plane consisting of the two carbonyl oxygens and nitrogen with cerium was about 180 degree. This complex was a yellow color unique for the DMDPhPDA-lanthanide complexes. The photo absorption peak for the complex was extremely broad, and the peak position was at a higher wavenumber as compared with those for the other lanthanide complexes. The peak in the highest wavenumber of this band may be attributed to the transition between f and d orbitals, which are greatly influenced by the ligand field of the DMDPhPDA. The XANES spectrum of the cerium complex clearly showed that cerium was trivalent.
Suzuki, Shinichi; Yaita, Tsuyoshi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Motohashi, Haruhiko*
Physica Scripta, T115, p.306 - 307, 2005/00
In spent fuel reprocessing, distribution behavior of technetium in tri- butyl phosphate (TBP) extraction system is a very complicated. Especially, in the presence of metallic ions, i.e., U(VI), Pu(IV)and Zr(IV)in the TBP extraction system, the extraction of technetium is enhanced by the co- extraction with U, Pu and Zr. The mechanism of co-extraction mechanism of technetium is performed by exchange with nitric acid ion and per-technetate ion. In this research, we perform the structural analysis of technetium complexes in ethanol solution compared with rhenium and manganese complexes by EXAFS. Furthermore we measured some organic complexes and co-extracted complexes of technetium with uranium and zirconium extracted by TBP as compared with those of rhenium.
Oya, Yasuhisa*; Morimoto, Yasutomi*; Oyaizu, Makoto*; Hirohata, Yuko*; Yagyu, Junichi; Miyo, Yasuhiko; Goto, Yoshitaka*; Sugiyama, Kazuyoshi*; Okuno, Kenji*; Miya, Naoyuki; et al.
Physica Scripta, T108, p.57 - 62, 2004/00
no abstracts in English
Sugiyama, Kazuyoshi*; Miyasaka, Kazutaka*; Tanabe, Tetsuo*; Masaki, Kei; Goto, Yoshitaka*; Tobita, Kenji; Kodama, Kozo; Miya, Naoyuki
Physica Scripta, T103, p.56 - 58, 2003/00
Times Cited Count：14 Percentile：62.26(Physics, Multidisciplinary)no abstracts in English
Shimura, Kenichiro*; Yamaguchi, Kenji; Terai, Takayuki*; Yamawaki, Michio*
Physica Scripta, T103, p.101 - 104, 2003/00
Times Cited Count：2 Percentile：21.20(Physics, Multidisciplinary)In this study, the kinetics of desorption of adsorbed hydrogen from an ideal metallic surface is modeled in Cellular Automaton (CA). The modeling is achieved by downgrading the surface to one dimension. The model consists of two parts that are, surface migration and desorption. The former is attained by randomly sorting the particles at each time, the latter is realized by modeling the thermally-activated process. For the verification of this model, thermal desorption is simulated and then the comparison with the chemical kinetics is carried out. Excellent agreement is observed from the result. The overall results show that this model is reasonable to express the recombinative desorption of two chemisorbed adatoms. Although the application of this model is limited to second-order reaction case, it can be believed that the groundwork of modeling the transport dynamics of hydrogen through the surface under complex conditions is established.
