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Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*
Advances in X-Ray Chemical Analysis, Japan, 54, p.89 - 99, 2023/03
Fundamental research on X-ray absorption imaging for elemental identification was studied. A secondary target was applied to obtain X-ray absorption images above and below the X-ray absorption edge of the target element. X-rays from an X-ray tube were irradiated to the secondary target, where the characteristic X-rays were emitted that were irradiated to the sample. X-ray absorption images were acquired with an exposure time of a few seconds with an X-ray camera. In this technique, it is difficult to change the energy of X-rays as we want, however we can apply this technique for imaging the specific element. Metal foil sample composed of Al, Cu, and Ni was analyzed. To obtain an X-ray elemental image of Ni, two X-ray absorption images were taken using the X-rays above and below the Ni K-edge. X-rays of Cu K
and Zn K were prepared by using Cu and Zn plates as the secondary target. Finally, the Ni elemental image was obtained by subtracting two images. Furthermore, the X-ray camera had a function of setting critical energies for imaging, thus it was demonstrated that an X-ray elemental image of Ni was obtained using a single secondary target without changing the secondary target.
Matsuyama, Tsugufumi*; Nakae, Masanori*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*
Spectrochimica Acta, Part B, 199, p.106593_1 - 106593_6, 2023/01
Times Cited Count：2 Percentile：45.92(Spectroscopy)Fuchita, Tomoki*; Urata, Taisei*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*
Advances in X-Ray Chemical Analysis, Japan, 53, p.77 - 87, 2022/03
X-ray fluorescence (XRF) analysis is an analytical method to obtain elemental information by detecting fluorescence X-rays emitted from a sample irradiated with X-rays. It is possible to obtain two-dimensional elemental distribution images by scanning a sample with micro X-ray beam. In this study, we developed an XRF analytical instrument to rapidly obtain the elemental distributions for moving samples on a belt conveyor by applying the micro XRF technique. X-rays were widely irradiated to the belt conveyor. The elemental distributions were measured by scanning an X-ray detector, crossing above the belt conveyor. A collimator was attached to the top of the detector to limit the analyzing area. Both detection limit and spatial resolutions for moving directions of the detector and the belt conveyor were evaluated. Finally, it was demonstrated that the multi-elemental imaging was possible with the developed XRF instrument.
Ouchi, Kazuki; Komatsu, Atsushi; Takao, Koichiro*; Kitatsuji, Yoshihiro; Watanabe, Masayuki
Chemistry Letters, 50(6), p.1169 - 1172, 2021/06
Times Cited Count：1 Percentile：6.77(Chemistry, Multidisciplinary)The electrochemical behavior of uranium (IV) tetrachloride in ionic liquid-DMF mixture was studied for first time in order to build a redox flow battery (RFB) using U as an electrode active material. We found a quasi-reversible U
/U
couple that could be applied to the anode reaction of the RFB.
-YbAlB
at high magnetic fieldsTerashima, Taku*; Matsuda, Yasuhiro*; Kuga, Kentaro*; Suzuki, Shintaro*; Matsumoto, Yosuke*; Nakatsuji, Satoru*; Kondo, Akihiro*; Kindo, Koichi*; Kawamura, Naomi*; Mizumaki, Masaichiro*; et al.
Journal of the Physical Society of Japan, 84(11), p.114715_1 - 114715_4, 2015/11
Times Cited Count：4 Percentile：34.89(Physics, Multidisciplinary)-YbAl
Fe
B (
) at low temperatures and high magnetic fieldsTerashima, Taku*; Matsuda, Yasuhiro*; Kuga, Kentaro*; Suzuki, Shintaro*; Matsumoto, Yosuke*; Nakatsuji, Satoru*; Kondo, Akihiro*; Kindo, Koichi*; Kawamura, Naomi*; Mizumaki, Masaichiro*; et al.
Journal of Physics; Conference Series, 592(1), p.012020_1 - 012020_6, 2015/03
Times Cited Count：1 Percentile：43.19(Physics, Atomic, Molecular & Chemical)Valence fluctuation phenomena in rare-earth intermetallic compounds have attracted attention because the quantum criticality of the valence transition has been proposed theoretically. Recently, it was found that 
-YbAlB shows quantum criticality without tuning and has a strong mixed-valence state. In this study, we measured the magnetization curve and X-ray magnetoabsorption in -YbAlFeB (), which is a locally isostructural polymorph of -YbAlB. The magnetization and X-ray experiments were performed in fields up to 55 and 40 T, respectively. A small increase in the Yb valence was observed at fields where the magnetization curve exhibited a change in slope.
Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Hirakawa, Yasushi; Furukawa, Tomohiro; Hoashi, Eiji*; Fukada, Satoshi*; Suzuki, Akihiro*; Yagi, Juro*; Tsuji, Yoshiyuki*; et al.
Proceedings of Plasma Conference 2014 (PLASMA 2014) (CD-ROM), 2 Pages, 2014/11
In the IFMIF/EVEDA (International Fusion Materials Irradiation Facility/ Engineering Validation and Engineering Design Activity), the validation tests of the EVEDA lithium test loop with the world's highest flow rate of 3000 L/min was succeeded in generating a 100 mm-wide and 25 mm-thick free-surface lithium flow steadily under the IFMIF operation condition of a high-speed of 15 m/s at 250
C in a vacuum of 10 
Pa. Some excellent results of the recent engineering validations including lithium purification, lithium safety, and remote handling technique were obtained, and the engineering design of lithium facility was also evaluated. These results will advance greatly the development of an accelerator-based neutron source to simulate the fusion reactor materials irradiation environment as an important key technology for the development of fusion reactor materials.
Yasuda, Mari; Tanaka, Kiwamu; Watanabe, Koichi; Hoshi, Akiko; Tsuji, Tomoyuki; Kameo, Yutaka
JAEA-Data/Code 2014-011, 59 Pages, 2014/08
JAEA-Data-Code-2014-011.pdf:16.84MB
Simple and rapid methods to evaluate the radioactivity concentrations are required to be established for the near surface disposal of radioactive wastes generated from research facilities at Japan Atomic Energy Agency. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid wastes generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid wastes generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In the present paper, we summarized data about the radioactivity concentrations which accumulated by the analysis.
Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Watanabe, Kazuyoshi; Ida, Mizuho*; Ito, Yuzuru; Niitsuma, Shigeto; Edao, Yuki; et al.
Fusion Science and Technology, 66(1), p.46 - 56, 2014/07
Times Cited Count：4 Percentile：30.92(Nuclear Science & Technology)Tanaka, Kiwamu; Yasuda, Mari; Watanabe, Koichi; Hoshi, Akiko; Tsuji, Tomoyuki; Higuchi, Hidekazu
JAEA-Data/Code 2013-008, 16 Pages, 2013/11
JAEA-Data-Code-2013-008.pdf:2.41MB
Simple and rapid methods to evaluate the radioactivity concentrations are required to be established for the near surface disposal of radioactive wastes generated from research facilities at Japan Atomic Energy Agency. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid wastes generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid wastes generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In the present paper, we summarized data about the radioactivity concentrations which accumulated by the analysis.
Hoshi, Akiko; Tsuji, Tomoyuki; Tanaka, Kiwamu; Yasuda, Mari; Watanabe, Koichi; Sakai, Akihiro; Kameo, Yutaka; Kogure, Hiroto; Higuchi, Hidekazu; Takahashi, Kuniaki
JAEA-Data/Code 2011-011, 31 Pages, 2011/10
JAEA-Data-Code-2011-011.pdf:1.7MB
Simple and rapid methods to evaluate the radioactivity concentrations are required to be established for the near surface disposal of radioactive wastes generated from research facilities at Japan Atomic Energy Agency. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid wastes generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid wastes generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In the present paper, we summarized data (262 data) about the radioactivity concentrations of the 7 important nuclides (
H, 
C, 
Co, 
Ni, 
Ni, 
Sr, 
Cs) which accumulated by the analysis.
Ogawa, Kanade; Akahane, Yutaka; Tsuji, Koichi; Yamakawa, Koichi
Reza Kenkyu, 38(10), p.779 - 783, 2010/10
We have newly designed a grism pair compensator for third-order dispersion in a fiber stretched chirped-pulse amplification system. In a numerical calculation, we have obtained a pedestal-free re-compressed pulse close to the transform-limited pulse using the grism pair. We have experimentally demonstrated a two-fold enhancement of peak intensity and pulse shortening of the compressed pulse with this device.
Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Aoyama, Makoto; Yamakawa, Koichi
Proceedings of SPIE, Vol.7589, p.75890L_1 - 75890L_8, 2010/02
Times Cited Count：0 Percentile：0.01(Engineering, Biomedical)We have proposed and demonstrated a very simple and robust femtosecond optical-parametric chirped-pulse amplification scheme in which an even order dispersion of an idler pulse is compensated by passing through an identical positive dispersive material used for temporal stretching a signal pulse. By compressing the idler pulses having a negatively chirp in this manner, high power sub-100 fs pulses were successfully obtained with only a transparent glass block used for the stretcher and compressor.
Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Aoyama, Makoto; Yamakawa, Koichi
Applied Physics Express, 2(7), p.072503_1 - 072503_3, 2009/07
Times Cited Count：4 Percentile：18.58(Physics, Applied)We have proposed and demonstrated a very simple and robust femtosecond optical-parametric chirped-pulse amplification scheme in which an even order dispersion of an idler pulse is compensated by passing through an identical positive dispersive material used for temporal stretching a signal pulse. By compressing the idler pulses having a negatively chirp in this manner, high power sub-100 fs pulses were successfully obtained with only a transparent glass block used for the stretcher and compressor. A feasible design of real world femtosecond laser systems employing this scheme is also discussed.
Ogawa, Kanade; Sueda, Keiichi*; Akahane, Yutaka; Aoyama, Makoto; Tsuji, Koichi; Fujioka, Kana*; Kanabe, Tadashi*; Yamakawa, Koichi; Miyanaga, Noriaki*
Optics Express (Internet), 17(10), p.7744 - 7749, 2009/05
Times Cited Count：13 Percentile：54.22(Optics)Using a partially deuterated KDP crystal for an optical parametric amplifier, we demonstrated ultrabroadband optical parametric chirped-pulse amplification of more than 250 nm bandwidth at a center wavelength of 1050 nm. We numerically show how to control the broadband phase matching conditions at different wavelengths to match center wavelengths of suitable broadband seed sources by adjusting the deuteration level in partially deuterated KDP.
Yamakawa, Koichi; Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi
Reza Kenkyu, 36(9), p.555 - 561, 2008/09
We review progress in the generation of ultrahigh-intensity optical pulses in a few-cycle regime. A design of a Generation of ENergetic Beam Ultimate (GENBU) laser based on optical parametric chirped-pulse amplification, which will be produced a peak power of up to 6-PW with a variable pulse durations ranging from 5-fs to 8-ps is described. Ultra-broadband optical parametric chirped-pulse amplification pumped by a picosecond laser pulse delivered from a diode-pumped, cryogenically-cooled Yb:YLF chirped-pulse amplification laser is also reported.
Ogawa, Kanade; Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Kawanaka, Junji*; Harimoto, Tetsuo*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
Japanese Journal of Applied Physics, 47(6), p.4592 - 4594, 2008/06
Times Cited Count：7 Percentile：30.06(Physics, Applied)We have demonstrated ultra-broadband optical parametric chirped-pulse amplification of more than 350 nm bandwidth in a near infrared region. We have observed a substantial enhancement (nearly 2-fold) of the parametric amplification bandwidth by using time delayed two broadband pump pulses at degeneracy.
crystalAkahane, Yutaka; Aoyama, Makoto; Sugiyama, Akira; Kubo, Ryoichi; Ogawa, Kanade; Tsuji, Koichi; Yamakawa, Koichi
Optics Letters, 33(5), p.494 - 496, 2008/03
Times Cited Count：2 Percentile：14.69(Optics)A diode-pumped, cryogenically-cooled Yb:LuLiF regenerative amplifier has been developed for the first time to our knowledge. A chirped-seed pulse was amplified and compressed in the regenerative amplifier, simultaneously, which generated 
6-mJ, 13-ps pulses at 999 nm wavelength without a pulse compressor. Simultaneous lasing at 999 nm and 1024 nm, respectively, was demonstrated, which could be used for different frequency generation in the THz region.
Ogawa, Kanade; Akahane, Yutaka; Harimoto, Tetsuo*; Aoyama, Makoto; Tsuji, Koichi; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
Reza Kenkyu, 35(9), p.596 - 598, 2007/09
no abstracts in English
)
chirped-pulse regenerative amplifierOgawa, Kanade; Akahane, Yutaka; Aoyama, Makoto; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi
Optics Express (Internet), 15(14), p.8598 - 8602, 2007/07
Times Cited Count：21 Percentile：68.17(Optics)Ytterbium (Yb
) doped gain media are one of promising laser materials for the next generation of diode-pumped high-power lasers. Yb-doped media have several advantages. It has wide absorption bandwidth, the low quantum defect, and the simple electronic structure. Yb:KY(WO) (Yb:KYW) and Yb:KG(WO) (Yb:KGW) have a large absorption and wide emission cross section, broad emission spectral range, and high thermal conductivity, yielding a high repetition-rate, high-energy, sub-picosecond pulses. However, multi-millijoule-class Yb:KYW or Yb:KGW lasers have not yet been reported so far, excepting a massive, joule-class Ti:sapphire laser pumped Yb:KGW regenerative amplifier. So, We developed a compact diode-pumped, cryogenically-cooled chirped-pulse Yb:KYW regenerative amplifier. An amplified pulse with an energy of 5.5 mJ and a high optical conversion efficiency of 14% is achieved. Regenerative pulse shaping is also used to counter gain narrowing during amplification.
