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Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tamura, Koji; Saeki, Morihisa
Kogaku, 48(1), p.13 - 20, 2019/01
By Laser Induced Breakdown Spectroscopy and by related resonance spectroscopy, elemental and isotope analysis of Uranium and Plutonium for nuclear fuel materials and in-situ remote analysis under strong radiation condition for melt downed nuclear fuel debris at damaged core in "Fukushima Daiichi Nuclear Power Station", are introduced and performed as one of the application in atomic energy research field.
-irradiated graphite surfaces using photon-stimulated desorption spectroscopySekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.
Surface and Interface Analysis, 38(4), p.352 - 356, 2006/04
Times Cited Count：3 Percentile：7.13(Chemistry, Physical)We investigated the orientation nature at the top-most layers of F-irradiated graphite using polarization dependent near-edge X-ray absorption fine structure (NEXAFS) spectroscopy which incorporates partial electron yield (PEY) detection and photon-stimulated ion desorption (PSID) techniques. The fluorine K-edge NEXAFS spectra conducted in PEY mode show no significant dependence on polarization angles. In contrast, NEXAFS spectra recorded in F ion yield mode show enhanced yields at a feature of 
689.4 eV assigned as a 
*(C-F) state relevant to =C-F sites, which depend on polarization angles. The C-F bonds prefer relatively tilting down the surface at the top-most layer, while the C-F bonds are randomly directed at deeper regions. We conclude that the difference in the orientation structures between the top surface and bulk is reflected in the NEXAFS recorded in the two different detection modes. It was also found that H- and F
- PSID NEXAFS spectra are helpful in understanding desorption mechanism, thus in analysing NEXAFS data.
Takahashi, Yoshio*; Murata, Miho*; Kimura, Takaumi
Journal of Alloys and Compounds, 408-412, p.1246 - 1251, 2006/02
Times Cited Count：24 Percentile：75.19(Chemistry, Physical)no abstracts in English
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Wu, G.*; Kitajima, Yoshinori*
Surface Science, 593(1-3), p.310 - 317, 2005/11
Times Cited Count：2 Percentile：11.64(Chemistry, Physical)Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids have been investigated. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed chlorobenzene.
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Baba, Yuji; Imamura, Motoyasu*; Matsubayashi, Nobuyuki*; Shimada, Hiromichi*
Surface Science, 593(1-3), p.303 - 309, 2005/11
Times Cited Count：5 Percentile：26.1(Chemistry, Physical)no abstracts in English
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.437 - 441, 2005/06
Times Cited Count：3 Percentile：17.55(Spectroscopy)no abstracts in English
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Koike, Masaki*
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.453 - 455, 2005/06
Times Cited Count：16 Percentile：56.9(Spectroscopy)no abstracts in English
Kizaki, Hiroyuki*; Wada, Shinichi*; Sako, Erika*; Sumii, Ryohei*; Waki, Satoshi*; Isari, Koji*; Sekitani, Tetsuji*; Sekiguchi, Tetsuhiro; Tanaka, Kenichiro*
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.447 - 451, 2005/06
Times Cited Count：5 Percentile：27.33(Spectroscopy)no abstracts in English
Kavakli, P. A.*; Seko, Noriaki; Tamada, Masao; G
ven, O.*
Separation Science and Technology, 39(7), p.1631 - 1643, 2005/00
Times Cited Count：58 Percentile：84.33(Chemistry, Multidisciplinary)A new type of fibrous adsorbent with excess amidoxime groups was synthesized by radiation-induced graft polymerization. Glycidyl methacrylate (GMA) was first radiation-grafted on polyethylene-coated polypropylene nonwoven fabrics and chemically modified with 3,30-iminodipropionitrile [NH (-CH
-CH-CN)] (IDPN), which was further reacted with hydroxylamine to obtain graft chains containing two amidoxime groups per graft repeating units. The adsorption properties of this new adsorbent for uranium (U), vanadium (V), lead (Pb), copper (Cu), and cobalt (Co) ions at low concentrations (3.3-1000 ppb).
Seko, Noriaki; Basuki, F.*; Tamada, Masao; Yoshii, Fumio
Reactive and Functional Polymers, 59(3), p.235 - 241, 2004/07
Times Cited Count：52 Percentile：82.06(Chemistry, Applied)Fibrous arsenic(As) adsorbent was synthesized by loading zirconium(Zr) on fibrous phosphoric adsorbent which was directly synthesized by radiation-induced grafting of 2-hydroxyethyl methacrylate phosphoric acid on polyethylene-coated polypropylene nonwoven fabric. Zirconium reacted with phosphoric acid grafted in the polyethylene layer. Zirconium density of the resulting adsorbent was 4.1 mmol/g. The breakthrough curve of As(V) adsorption was independent of the flow rate up to 1300 h
in space velocity. The total capacity of As(V) was 2.0 mmol/ g-adsorbent at pH of 2. The adsorbed Zr(IV) could be evaluated by 0.4 M sodium hydroxide solution because no Zr(IV) could be found in the eluted solution. Anions of chloride and nitrate interfered the breakthrough capacity.
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.
Free Electron lasers 2003, p.II_69 - II_70, 2004/00
no abstracts in English
Sekiguchi, Tetsuhiro; Ikeura-Sekiguchi, Hiromi*; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.
Photon Factory Activity Report 2002, Part B, P. 80, 2003/11
no abstracts in English
Sekiguchi, Tetsuhiro; Ikeura, Hiromi*; Baba, Yuji
Surface Science, 532-535(1-3), p.1079 - 1084, 2003/06
Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, we have investigated orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed formic acid, formamide and benzene. For condensed formamide(HCOND), marked orientation effect was observed for the enhanced H-yields following C1s 
*
resonance. Direct photodissociation and charge-neutralization play an important role in the effect. For some fragment species, however, the bond scission showed no polarization dependence when dissociation sites were far from core-excited atoms. This is the case for N-D scission and D-desorption following C1s excitation, suggesting that indirect process governs, where secondary electrons would induce the fragmentation.
Wada, Shinichi*; Sumii, Ryohei*; Isari, Koji*; Waki, Satoshi*; Sako, Erika*; Sekiguchi, Tetsuhiro; Sekitani, Tetsuji*; Tanaka, Kenichiro*
Surface Science, 528(1-3), p.242 - 248, 2003/03
Times Cited Count：45 Percentile：84.36(Chemistry, Physical)no abstracts in English
Wada, Shinichi*; Sako, Erika*; Sumii, Ryohei*; Waki, Satoshi*; Isari, Koji*; Sekiguchi, Tetsuhiro; Sekitani, Tetsuji*; Tanaka, Kenichiro*
Nuclear Instruments and Methods in Physics Research B, 199, p.361 - 365, 2003/01
Times Cited Count：11 Percentile：59.28(Instruments & Instrumentation)no abstracts in English
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Kitajima, Yoshinori*; Baba, Yuji
Applied Surface Science, 169-170, p.282 - 286, 2001/01
Times Cited Count：8 Percentile：44.9(Chemistry, Physical)Carbon and nitrogen K-shell excitation and dissociation of condensed formamide at 96 K were studied by near edge X-ray absorption fine structure (NEXAFS) recorded by total electron yield (TEY), total ion yield (TIY) and photon-stimulated desorption (PSD) yield of H+ measurements. It was found that electronic transitions from the C1s or the N1s to the *(C-H) and/or (N-H) enhanced ion yield of H+ from the C-H and/or N-H functional group. This selective dissociation indicates that the corresponding unoccupied molecular orbital has an antibonding character of the C-H and/or N-H. To investigate the molecular orientation of condensed formamide, incidence-angle-dependent TEY-NEXAFS spectra were measured. The CNO plane of the adsorbed formamide molecule is determined to be tilted away from the surface by an averaged angle of about 42 degrees.
Sekiguchi, Tetsuhiro; Baba, Yuji
Atomic Collision Research in Japan, No.24, p.118 - 119, 1998/11
no abstracts in English
Saeki, Masakatsu; Hirabayashi, Takakuni
Radiochimica Acta, 38, p.37 - 41, 1985/00
no abstracts in English
Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Masaki; Ito, Chikara; Saeki, Morihisa; Kato, Masaaki
no journal, ,
In nuclear engineering, especially for the decommissioning of severe accident atomic power plant, development of quick, easy, non-contact, no-preparation, direct, remote, onsite and in-situ analysis of nuclear fuel materials which has very complex and large amount of optical emission lines will be indispensable. In these R&D, it may be important how we realize high sensitivity and high resolution spectroscopy and perform the identification of the specific element among a large number of emission spectra. Various kind of technique, such as Double-pulse LIBS and Microwave assisted LIBS for multiply the emission intensity, high resolution LIBS by ultra-high resolution spectrometer or Laser Ablation Resonance Absorption Spectroscopy for isotope analysis, Ultra-thin Liquid flow LIBS for liquid phase application and LIBS based on radiation resistant optical fiber for onsite/in-situ monitoring of melt downed nuclear fuel debris, will have been under investigation. Japan Atomic Energy Agency has opened the new research center "Collaborative Laboratories for Advanced Decommissioning Science", and laser based spectroscopy will be restarted as one of the basic projects.
Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Hironori; Saeki, Morihisa; Oba, Masaki; Ito, Chikara; Kato, Masaaki
no journal, ,
Laser Induced Breakdown Spectroscopy (LIBS) for elemental analysis and Laser Ablation Resonance Absorption Spectroscopy (LARAS) for isotope analysis have been developed as an analytical technique for Low-decontaminated MOX fuel with fissionable Miner Actinide elements (MA) and as for one of the diagnostic tool of nuclear fuel debris and polluted materials in the decommissioning of the severe accident nuclear power station. Specialized glove box with auto and remote arraignment system for LIBS and LARAS was constructed, and the detection limit of Pu in MOX to be several 1000 ppm and some hyper fine structures of 
Pu were demonstrated. For the diagnostic tool in the decommissioning of damaged core, optical fiber based portable LIBS probe made by radiation resistant optical fiber is under construction, and just now, some specific spectra from the simulated sample of molten debris made by sintered oxide of Zr and U is successfully observed under water condition or strong radiation field.
