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Frandsen, B. A.*; Liu, L.*; Cheung, S. C.*; Guguchia, Z.*; Khasanov, R.*; Morenzoni, E.*; Munsie, T. J. S.*; Hallas, A. M.*; Wilson, M. N.*; Cai, Y.*; et al.
Nature Communications (Internet), 7, p.12519_1 - 12519_8, 2016/08
Times Cited Count:33 Percentile:76.78(Multidisciplinary Sciences)Alonso, M. C.*; Garca Calvo, J. L.*; Pettersson, S.*; Cuado, M.*; Vuorio, M.*; Weber, H.*; Ueda, Hiroyoshi*; Naito, Morimasa; Walker, C.
Proceedings of 13th International Congress on the Chemistry of Cement (13th ICCC) (CD-ROM), 7 Pages, 2011/07
Low pH cementitious (LopHC) materials are expected to be used in the construction of an underground repository for the geological disposal of high level radioactive waste (HLW). A fundamental aspect of the development of LopHC is the accurate and reliable measurement of the pore fluid pH in order to qualify and help quantify mix designs to achieve specific pH targets. The main objective of the current research is the development of an agreed protocol for measuring the pH value of LopHC. There are four different methods described in the literature for characterizing the pore solution of cementitious materials: (1) Pore fluid expression; (2) Leaching methods, including both in-situ and ex-situ techniques); (3) Percolation methods; and (4) Embedded pH sensors. In a first step, different parameters that may affect the measured pH values were evaluated, including the solid/liquid ratio, fineness, carbonation, time, and the results obtained from a pH meter in comparison with an OH titration. Based on the results obtained from the first step, selected protocols were proposed and tested for reproducibility and repeatability in 8 laboratories of 7 countries using the same LopHC sample. The proposed methodologies showed very promising results with low deviation and high reproducibility and have allowed the development of an agreed set of simple protocols for the determination of pH in LopHC.
Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.
Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12
Times Cited Count:17 Percentile:72.53(Nuclear Science & Technology)no abstracts in English
Butorin, S. M.*; Sthe, C.*; Agui, Akane; Saalem, F.*; Alonso, J. A.*; Nordgren, J.*
Solid State Communications, 135(11-12), p.716 - 720, 2005/09
Times Cited Count:5 Percentile:26.07(Physics, Condensed Matter)no abstracts in English
Fukuda, Yuji; Kanasaki, Masato; Jinno, Satoshi*; Sakaki, Hironao; Nishiuchi, Mamiko; Faenov, A.*; Pikuz, T.*; Kiriyama, Hiromitsu; Kando, Masaki; Kondo, Kiminori; et al.
no journal, ,
In this study, to understand the synergetic interplay between the Coulomb explosion of clusters and the background gas dynamics, we have conducted ion acceleration experiments using CO clusters embedded in background H gas with the J-KAREN laser at JAEA-KPSI. As a result, energy spectra for protons (from background gas) and carbon/oxygen ions (from clusters) are obtained separately for the first time. We found that the maximum energies of protons and carbon/oxygen ions are 1.5 MeV and 1.1 MeV/u, respectively. Based on the experimental results, the acceleration mechanism of background gas ions induced by Coulomb explosion of clusters is discussed with the help from numerical simulations which employ a particle-in-cell (PIC) method including relaxation and ionization processes of plasma particles (EPIC3D).
Fukuda, Yuji; Kanasaki, Masato; Jinno, Satoshi*; Sakaki, Hironao; Nishiuchi, Mamiko; Faenov, A.*; Pikuz, T.*; Kiriyama, Hiromitsu; Kando, Masaki; Kondo, Kiminori; et al.
no journal, ,
In the laser-driven ion acceleration using cluster-gas target, the acceleration mechanism consists of different processes such as, (a) acceleration of ions due to Coulomb explosion of individual clusters, (b) compression and acceleration of background gas ions due to the Coulomb explosion of clusters, (c) magnetic vortex generation and associated pinching near the rear surface, and (d) sheath acceleration at the interface between the medium and vacuum. To understand the synergetic interplay between the Coulomb explosion of clusters and the background gas dynamics, we have conducted ion acceleration experiments using CO clusters embedded in background H gas with the J-KAREN laser at JAEA-KPSI. By a careful analysis of CR-39, energy spectra for protons (from background gas) and carbon/oxygen ions (from clusters) are obtained separately for the first time. We found that the maximum energies of protons and carbon/oxygen ions are 1.5 MeV and 1.1 MeV/u, respectively. Based on the experimental results, the acceleration mechanism of background gas ions induced by Coulomb explosion of clusters is discussed with the help from numerical simulations which employ a particle-in-cell (PIC) method including relaxation and ionization processes of plasma particles (EPIC3D).
Kanasaki, Masato; Jinno, Satoshi*; Sakaki, Hironao; Faenov, A.*; Pikuz, T. A.*; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Kando, Masaki; Kondo, Kiminori; Matsui, Ryutaro; et al.
no journal, ,
In the previous laser-driven ion acceleration experiment using cluster-gas target, we have only focused on the high energy ions with energies of multi-tens of MeV. In order to reveal synergetic interplay between the Coulomb explosion of clusters and the background gas ions, we have measured protons (background gas ions) separately from carbon and oxygen ions (clusters) by using magnetic spectrometer with CR-39 track detectors. We have found that the number of carbon and oxygen ions decrease sharply at 1 MeV/n. On the other hand, the protons show the Maxwell-Boltzmann energy distribution. Based on the experimental results, the acceleration mechanism of background gas ions induced by Coulomb explosion of clusters can be discussed with the help from numerical simulations.
Fukuda, Yuji; Kanasaki, Masato*; Jinno, Satoshi*; Sakaki, Hironao; Nishiuchi, Mamiko; Pirozhkov, A. S.; Kiriyama, Hiromitsu; Kando, Masaki; Kondo, Kiminori; Pikuz, T. A.*; et al.
no journal, ,
In order to understand the synergetic interplay between the Coulomb explosion of clusters and the background gas dynamics, an energy spectrum of carbon/oxygen ions from the CO clusters and that of protons from the background hydrogen gas are measured separately at 110 W/cm with a careful analysis of etch pit structures on CR-39. The maximum energies of carbon/oxygen ions and protons are determined as 1.1 MeV/n and 1.6 MeV, respectively. Moreover, we present a development of submicron-size hydrogen cluster targets using a cryogenic conical nozzle and their characterization with the Mie scattering method. Above 10 W/cm, the anisotropic Coulomb explosion of submicron-size hydrogen clusters could produce directional proton beams with energies of several tens of MeV, quite advantageous to the future applications, since they are inherently impurity-free, high rep.rate, and robust.