Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
-ray discrimination based on the property and thickness controls of scintillators using Li glass and LiCAF(Ce) in a -ray fieldKaburagi, Masaaki; Shimazoe, Kenji*; Terasaka, Yuta; Tomita, Hideki*; Yoshihashi, Sachiko*; Yamazaki, Atsushi*; Uritani, Akira*; Takahashi, Hiroyuki*
Nuclear Instruments and Methods in Physics Research A, 1046, p.167636_1 - 167636_8, 2023/01
Times Cited Count：3 Percentile：90.12(Instruments & Instrumentation)We focus on the thickness and property controls of inorganic scintillators used for thermal neutron detection in intense -ray fields without considering pulse shape discrimination techniques. GS20
(a lithium glass) and LiCaAlF
:Ce(LiCAF:Ce) cintillators with thicknesses of 0.5 and 1.0 mm, respectively, have been employed. Pulse signals generated by photomultiplier tubes, to which the scintillators were coupled, were inserted into a digital pulse processing unit with 1 Gsps, and the areas of waveforms were integrated for 360 ns. In a 
Co -ray field, the neutron detection for GS20 with a 0.5-mm thickness was possible at dose rates of up to 0.919 Gy/h; however, for LiCAF:Ce, neutron detection was possible at 0.473 Gy/h, and it failed at 0.709 Gy/h. Threfore, in a Co -ray field, the neutron/-ray discrimination of GS20 was better than that of LiCAF:Ce due to its better energy resolution and higher detection efficiency.
Yamaguchi, Mika; Hidaka, Akihide; Ikuta, Yuko; Murakami, Kenta*; Tomita, Akira*; Hirose, Hiroya*; Watanebe, Masanori*; Ueda, Kinichi*; Namaizawa, Ken*; Onose, Takatoshi*; et al.
JAEA-Review 2017-002, 60 Pages, 2017/03
JAEA-Review-2017-002.pdf:9.41MB
Since 2010, IAEA has held the NEM School to develop future leaders who plan and manage nuclear energy utilization in their county. Since 2012, JAEA together with Japan Nuclear HRD Network, University of Tokyo, Japan Atomic Industrial Forum and JAIF International Cooperation Center have cohosted the school in Japan in cooperation with IAEA. Since then, the school has been held in Japan every year. In 2006, Japanese nuclear technology and experience, such as lessons learned from the Fukushima Daiichi Nuclear Power Plant accident, were provided to offer a unique opportunity for the participants to learn about particular cases in Japan. Through the school, we contributed to the internationalization of Japanese young nuclear professionals, development of nuclear human resource of other countries including nuclear newcomers, and enhanced cooperative relationship with IAEA. Additionally, collaborative relationship within the network was strengthened by organizing the school in Japan.
Hasegawa, Noboru; Ochi, Yoshihiro; Kawachi, Tetsuya; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Kaihori, Takeshi; Morita, Toshimasa; Sasaki, Akira; Terakawa, Kota*; et al.
X-Ray Lasers 2012; Springer Proceedings in Physics, Vol.147, p.117 - 120, 2014/00
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)We have developed the femto-second laser pump and soft X-ray laser probe system in order to observe the dynamical processes of the femto-second laser ablation. By using this system, we succeed to obtain the temporal evolution of the soft X-ray reflectivity from the laser induced Pt surface. The results lead that the rate of decrease in the reflectivity of the probe beam has a non-linear relation with the pump laser fluence.
Hasegawa, Noboru; Ochi, Yoshihiro; Kawachi, Tetsuya; Terakawa, Kota*; Tomita, Takuro*; Yamamoto, Minoru; Nishikino, Masaharu; Oba, Toshiyuki; Kaihori, Takeshi; Imazono, Takashi; et al.
X-Ray Lasers 2010; Springer Proceedings in Physics, Vol.136, p.353 - 358, 2011/12
The understanding of the dynamics of the initial process is important for the micro processing and welding by the ultra-short laser pulse. The X-ray laser is suitable for probing this initial process because it has short wavelength (Ni-like Ag, 13.9 nm) and short duration (7 ps). For this investigation, the origin of time of the pumping pulse is quite important. In this study, we used the scintillation plate and the plasma gate technique to realize the spatial and temporal synchronization of the pump and probe pulses. For the spatial alignment, a CsI scintillation plate that was set at the sample position was illuminated by both the X-ray laser pulse, and the fluorescence light were detected by the CCD camera. For the temporal synchronization, we set a thin foil at the sample position. We measured the transmission of the X-ray laser while changing a temporal delay of the pumping laser with respect to the time of X-ray laser pulse to obtain the origin of the irradiation time.
Hasegawa, Noboru; Ochi, Yoshihiro; Kawachi, Tetsuya; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Kaihori, Takeshi; Sasaki, Akira; Terakawa, Kota*; Minami, Yasuo*; et al.
Proceedings of SPIE, Vol.8140, p.81400G_1 - 81400G_8, 2011/10
Times Cited Count：3 Percentile：82.2(Engineering, Electrical & Electronic)We have developed a soft X-ray laser (SXRL) interferometer capable of the single-shot imaging of nano-scaled structure dynamics. The interferometer consisted of the reflection optics including double Lloyd's mirrors and focusing optics, and the interference fringes are produced on the detector surface. By using this interferometer, the initial stage (
50 ps) of the ablation process of the Pt surface pumped by a 70 fs Ti:Sapphire laser pulse was observed. The expansion speed of the surface estimated from the result (34 nm/50 ps) indicated that the nano-bubble structures were formed in the initial stage of the ablation. In order to observe the detailed dynamics, the temporal synchronization between the pump and probe pulses was improved to be 3 ps by adopting a portion of the SXRL and pump beams as the time fiducials, to which the pump and probe timing was adjusted by using the X-ray streak camera.
Horie, Akira*; Tomita, Takeo*; Saiki, Asako*; Kono, Hidetoshi; Taka, Hikari*; Mineki, Reiko*; Fujimura, Tsutomu*; Nishiyama, Chiharu*; Kuzuyama, Tomohisa*; Nishiyama, Makoto*
Nature Chemical Biology, 5(9), p.673 - 679, 2009/09
Times Cited Count：43 Percentile：67.5(Biochemistry & Molecular Biology)Oshima, Jun; Ashida, Takashi; Isozaki, Kazunori; Sumino, Kozo; Yamaguchi, Akira; Sakaba, Hideo; Ozawa, Kenji; Tomita, Naoki
JNC TN9410 2004-011, 279 Pages, 2004/04
JNC-TN9410-2004-011.pdf:68.76MB
The MK-III project to improve the irradiation capability of the experimental fast reactor JOYO have been carried out since 1987.The increase of fast neutron flux and the enlargement of irradiation field increase the reactor thermal power from 100MWt to 140MWt. To accommodate the increased thermal power,the IHXs and the IHX connecting piping were replaced. The IHXs were replaced with securing cooling system boundary in high dose rate surroundings and very limited operation space of the radiation controlled area in the containment vessel. Primary sodium contains radioactive 22Na,24Na and radioactive CPs such as 60Co and 54Mn,and this sodium adhered to the inner surface of IHXs and pipe. Therefore, the renovation procedure and method were carefully examined based on the JOYO operation and maintenance experiences and research and development results on the sodium handling technique.The major results obtained in the primary heat transport mechanical system (IHXs) renovation operation were shown as follows;
Sawai, Tomotsugu; Wakai, Eiichi; Tomita, Takeshi; Naito, Akira; Jitsukawa, Shiro
Journal of Nuclear Materials, 307-311(Part1), p.312 - 316, 2002/12
Times Cited Count：20 Percentile：76.08(Materials Science, Multidisciplinary)TIG-weld joints of the IEA heat of F82H were irradiated by TIARA. Transmission electron microscope (TEM) specimens were prepared by a focused ion beam (FIB) system. TEM specimens were obtained from the heat affected zone (HAZ) and the weld metal. HAZ specimens had typical bi-modal cavity microstructure after 50 dpa at 450
C with He/dpa ratio of 10 appmHe/dpa. Larger voids about 30 nm were observed in the tempered side specimen, while the size of voids in the quenched side specimen was less than 15 nm. Ac1 temperature determined by heat-treated base metal is 820C. Cavity growth in specimens tempered at higher temperature was enhanced, while that in cold worked ones is suppressed.
F+
Tb reactionIkezoe, Hiroshi; Nagame, Yuichiro; *; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Hamada, S.; ; Iwamoto, Akira; *
Physical Review C, 49(2), p.968 - 976, 1994/02
Times Cited Count：24 Percentile：79.73(Physics, Nuclear)no abstracts in English
Ikezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; *; B.J.Qi*; H.J.Kim*; Iwamoto, Akira; et al.
Physical Review C, 46(5), p.1922 - 1933, 1992/11
Times Cited Count：43 Percentile：89.14(Physics, Nuclear)no abstracts in English
Iwamoto, Akira; Tomita, Yoshiaki
Progress of Theoretical Physics, 87(5), p.1171 - 1184, 1992/05
no abstracts in English
Ikezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Otsuki, Tsutomu*; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Kanno, Ikuo; H.J.Kim*; B.J.Qi*; et al.
Nuclear Physics A, 538, p.299C - 306C, 1992/00
no abstracts in English
H and 
He emissions in 
O + 
Au reactionIkezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Iwamoto, Akira; Otsuki, Tsutomu*
Physical Review C, 42(4), p.1187 - 1190, 1990/10
Times Cited Count：16 Percentile：61.45(Physics, Nuclear)no abstracts in English
He multiplicity in the F + Au reactionIkezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Iwamoto, Akira; *
Physical Review C, 42(1), p.342 - 353, 1990/07
Times Cited Count：34 Percentile：85.86(Physics, Nuclear)no abstracts in English
Sonoda, Katsumi*; Yamamoto, Yasushi*; Hashimoto, Osamu*; Ono, Toshio*; Tomita, Haruhiko*; Udagawa, Akira; Egusa, Shigenori; Sasuga, Tsuneo; Seguchi, Tadao; Tamura, Naoyuki
Japanese Journal of Applied Physics, Part 1, 28(10), p.1950 - 1956, 1989/10
Times Cited Count：0 Percentile：0.01(Physics, Applied)no abstracts in English
Ochi, Yoshihiro; Hasegawa, Noboru; Kawachi, Tetsuya; Terakawa, Kota*; Suemoto, Toru*; Tomita, Takuro*; Yamamoto, Minoru*; Deki, Manato*; Tanaka, Momoko; Nishikino, Masaharu; et al.
no journal, ,
We have developed a chirped pulse amplification laser with zigzag slab Nd:glass power amplifiers which provides two synchronized beams with energy of 10 J and duration of a few ps at 0.1-Hz repetition-rate. Using this laser as a driver, fully spatial coherent X-ray laser at a wavelength of 13.9 nm is generated at 0.1 Hz. Typical energy, beam divergence and duration of the X-ray laser are 1 
J, 0.5 mrad and 7 ps, respectively. Hence, a quite high peak brilliance is achieved. Using this X-ray laser, various application researches have been started.
Ochi, Yoshihiro; Kawachi, Tetsuya; Hasegawa, Noboru; Terakawa, Kota*; Suemoto, Toru; Tomita, Takuro*; Yamamoto, Minoru*; Deki, Manato*; Tanaka, Momoko; Nishikino, Masaharu; et al.
no journal, ,
no abstracts in English
Ochi, Yoshihiro; Kawachi, Tetsuya; Hasegawa, Noboru; Nishikino, Masaharu; Tanaka, Momoko; Oba, Toshiyuki; Kishimoto, Maki; Ishino, Masahiko; Imazono, Takashi; Kaihori, Takeshi; et al.
no journal, ,
no abstracts in English
Nishikino, Masaharu; Ochi, Yoshihiro; Hasegawa, Noboru; Kawachi, Tetsuya; Ishino, Masahiko; Imazono, Takashi; Tanaka, Momoko; Sato, Katsutoshi; Yamamoto, Minoru; Oba, Toshiyuki; et al.
no journal, ,
Recent Progress in the development of laser-driven plasma soft X-ray laser (XRL) and the applications are presented. In the source development, TOPAZ laser using Nd:glass zigzag slab amplifiers with 10 J, 0.1 Hz repetition-rate routinely provides the fully spatial coherent X-ray laser at 13.9 nm for the applications. The bright, coherent, and picoseconds X-ray pulse can be used in a variety of applications such as X-ray speckle measurement and interferometer for probing materials, diffraction imaging, nano-scale fabrication, radiation biology, and so on. In order to extend the use of XRLs, now we are constructing new XRL beam lines for the optical pump and XRL probe experiment.
Nishikino, Masaharu; Hasegawa, Noboru; Ishino, Masahiko; Ochi, Yoshihiro; Kawachi, Tetsuya; Imazono, Takashi; Yamamoto, Minoru; Sasaki, Akira; Kaihori, Takeshi; Yamagiwa, Mitsuru; et al.
no journal, ,
no abstracts in English
