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Uno, Yuki; Ouchi, Yasuhiro; Ouchi, Satoshi; Baba, Ryota; Kikuchi, Masanobu; Kawamata, Satoshi
JAEA-Technology 2021-046, 39 Pages, 2023/02
JRR-3 (Japan Research Reactor No.3) is a light water research reactor cooling pool type light water deceleration of low-enriched uranium up to 20MW thermal power. November 1990, begin to operation in modified that we are provided to users as a high neutron flux form reactor facility in various types of irradiation facilities and neutron beam experiment equipment. Currently, JRR-3 has completed the period of facility inspections, which had been extended due to the effects of the Great East Japan Earthquake of March 11, 2011, and has been able to conformity to the New Regulatory Requirements. It has also resumed operation for the first time in about 10 years. FY 2017, overhauled the primary cooling heat exchanger No.1 and No.2 based on a maintenance plan. This is report for take advantage what inspection and maintenance of future about overhaul of the primary cooling system heat exchanger for collect of inspection records and performance.
Baba, Motoyoshi*; Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Minami, Yasuo*; Takei, Ryota*; Yamagiwa, Mitsuru; Kawachi, Tetsuya; Suemoto, Toru
Japanese Journal of Applied Physics, 53(8), p.080302_1 - 080302_4, 2014/08
Times Cited Count:7 Percentile:30.85(Physics, Applied)A grazing incidence reflection-type soft X-ay microscope, using a Fresnel zone plate and a soft X-ray laser with wavelength 13.9 nm and pulse width 7 ps, was developed. Submicron size groove structures made on a Pt film were clearly captured at a single shot exposure, with spatial resolution of about 360 nm. A wide field view of 100 m square was secured under the Kohler illumination. This microscope also had a large depth of focus of more than 100 m and was proven to have a sufficient performance for observing surface morphological changes.
Tomita, Takuro*; Nishikino, Masaharu; Hasegawa, Noboru; Minami, Yasuo*; Takei, Ryota*; Baba, Motoyoshi*; Eyama, Tsuyoshi*; Takayoshi, Shodai*; Kaihori, Takeshi*; Morita, Toshimasa; et al.
Journal of Laser Micro/Nanoengineering, 9(2), p.137 - 142, 2014/06
Times Cited Count:5 Percentile:29.55(Nanoscience & Nanotechnology)Femtosecond laser ablation processes on platinum, gold, and tungsten were observed by the single shot pump and probe reflective imaging using a soft X-ray laser probe. To avoid the timing error due to the jitter, we adopted a posteriori correction technique by simultaneous measurement of timing between the pump and probe pulses for every single shot, using a soft X-ray streak camera. A clear difference was found in the temporal behavior of the dynamical response of the soft X-ray reflectivity depending on the irradiated laser fluence in these three materials. On the other hand, the narrow dark rings were found in Pt and W, while an additional bright ring was found outside the dark disk in Au. Our result gives the experimental data comparable with various numerical simulations.
Nishikino, Masaharu; Hasegawa, Noboru; Ishino, Masahiko; Yamagiwa, Mitsuru; Kawachi, Tetsuya; Minami, Yasuo*; Terakawa, Kota*; Takei, Ryota*; Baba, Motoyoshi*; Suemoto, Toru; et al.
JAEA-Conf 2013-001, p.16 - 19, 2013/09
The dynamics of the femtosecond laser ablation is still not clear at the early stage. Several studies on the time-resolved imaging of femtosecond laser ablation process have been performed on various materials. In this study, we have demonstrated a pump and probe imaging of the metal surface morphology during the femtosecond laser ablation by using the laser-driven plasma induced soft X-ray laser (SXRL) as a probe beam. The pumping laser used for ablation was a Ti:Sapphire laser system based on chirped pulse amplification. The pump beam had a Gaussian profile and the focal spot size on the metal surface was about 70 micron at FWHM. The dependence for the pump laser fluence of the ablation surface expansion and the surface condition (roughness and density gradient) were observed from the soft X-ray interferogram and reflective image, respectively.
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Minami, Yasuo*; Takei, Ryota*; Baba, Motoyoshi*; Eyama, Tsuyoshi*; Takayoshi, Shodai*; Kawachi, Tetsuya; Hatomi, Daiki*; et al.
Proceedings of SPIE, Vol.8849, p.88490E_1 - 88490E_6, 2013/09
Times Cited Count:2 Percentile:73.12(Optics)We have developed the pump and probe interferometer and reflective imaging technique of the metal surfaces during the femtosecond laser ablation by using the laser-driven soft X-ray laser at the wavelength of 13.9 nm. The pumping laser used for ablation was a Ti: Sapphire laser pulse with the duration of 80 fs pulse at a central wavelength of 795 nm, and had a gaussian spatial profile. By using the X-ray imaging technique, the time resolved image of nano-scaled ablation dynamics of the platinum and the gold pumped by a femtosecond laser pulse was obtained.
Hasegawa, Noboru; Kawachi, Tetsuya; Nishikino, Masaharu; Ochi, Yoshihiro; Terakawa, Kota*; Takei, Ryota*; Minami, Yasuo*; Baba, Motoyoshi*; Suemoto, Toru; Yamagiwa, Mitsuru
no journal, ,
We developed the soft X-ray laser interferometer synchronized with Ti:Sapphire laser pulse for the measurement of the nanometer-scaled surface dynamics. The soft X-ray laser is suitable for probing the initial process of the surface morphological changes, because it has the suitable wavelength (= 13.9 nm), short duration (= 7 ps) and large photon numbers. By using this system, we succeed to obtain the temporal evolution of ablation front erupting from the laser induced Pt film. From this result, it was revealed that the expansion speed of the ablation front decreased continually from the center (= 2200 m/s) to the edge (= 420 m/s) of the ablation area in the initial stage of the ablation process.
Hasegawa, Noboru; Nishikino, Masaharu; Yamagiwa, Mitsuru; Kawachi, Tetsuya; Suemoto, Toru; Tomita, Takuro*; Baba, Motoyoshi*; Terakawa, Kota*; Minami, Yasuo*; Takei, Ryota*
no journal, ,
The dynamical processes of the laser-induced surface modifications such as laser ablation come to attract much attention for the micro processing by the ultra-short laser pulse. The soft X-ray laser (SXRL) is suitable for probing the initial process of the surface morphological changes, because it has the suitable wavelength (= 13.9 nm, penetration depth = 5 nm), short duration (= 7 ps) and large photon numbers (larger than 1e+10 photons/shot). In this study, we have developed the femto-second laser pump and soft X-ray laser probe system with the soft X-ray interferometer 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 laser induced Pt surface. From this result, it was revealed that the expansion speed of the ablation front at the center (= 1500 m/s) of the ablation area in the initial stage of the ablation process.
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Takei, Ryota*; Baba, Motoyoshi*; Kawachi, Tetsuya; Yamagiwa, Mitsuru; Suemoto, Toru
no journal, ,
no abstracts in English
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Takei, Ryota*; Baba, Motoyoshi*; Kawachi, Tetsuya; Yamagiwa, Mitsuru; Suemoto, Toru
no journal, ,
no abstracts in English
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Minami, Yasuo*; Takei, Ryota*; Ishino, Masahiko; Terakawa, Kota*; Eyama, Tsuyoshi*; Takayoshi, Shodai*; Kawachi, Tetsuya; et al.
no journal, ,
no abstracts in English
Hasegawa, Noboru; Nishikino, Masaharu; Yamagiwa, Mitsuru; Kawachi, Tetsuya; Suemoto, Toru; Tomita, Takuro*; Takei, Ryota*; Baba, Motoyoshi*
no journal, ,
The dynamical processes of the laser-induced surface modifications such as laser ablation come to attract much attention for the micro processing by the ultra-short laser pulse. The soft X-ray laser (SXRL) is suitable for probing the initial process of the surface morphological changes, because it has the suitable wavelength (= 13.9 nm, penetration depth = 5 nm), short duration (= 7 ps) and large photon numbers (larger than 1e+10 photons/shot). In this study, we have developed the femto-second laser pump and soft X-ray laser probe system with the soft X-ray interferometer in order to observe the dynamical processes of the femto-second laser ablation. By using this system, we measured the surface roughness and surface modifications of the laser induced metal surface. From this result, we succeeded to obtain the clear dependence for the material (Pt, Au, W) of the laser ablation dynamics.
Hasegawa, Noboru; Nishikino, Masaharu; Kaihori, Takeshi*; Hirano, Yusuke; Morita, Toshimasa; Kawachi, Tetsuya; Yamagiwa, Mitsuru; Tomita, Takuro*; Minami, Yasuo*; Terakawa, Kota*; et al.
no journal, ,
no abstracts in English
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Minami, Yasuo*; Takei, Ryota*; Baba, Motoyoshi*; Eyama, Tsuyoshi*; Takayoshi, Shodai*; Kawachi, Tetsuya; Yamagiwa, Mitsuru; et al.
no journal, ,
We have developed the pump and probe interferometer and reflective imaging technique of the metal surfaces during the femtosecond laser ablation by using the laser-driven soft X-ray laser at the wavelength of 13.9 nm. The pumping laser used for the ablation was a Ti: Sapphire laser pulse with the duration of 80 fs pulse at a central wavelength of 795 nm, and had a gaussian spatial profile. By using the X-ray imaging technique, the time resolved image of nano-scaled ablation dynamics of the platinum, the gold, the tungsten were obtained. We have compared the plasma expansion measured by the X-ray interferometer with the ablated hole measured by the atomic force microscopy, and discussed the fluence dependence of the femtosecond laser ablation.
Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Onishi, Naofumi*; Hatomi, Daiki*; Ito, Atsushi*; Minami, Yasuo*; Takei, Ryota*; et al.
no journal, ,
no abstracts in English
Yamagiwa, Mitsuru; Hasegawa, Noboru; Nishikino, Masaharu; Tomita, Takuro*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Onishi, Naofumi*; Hatomi, Daiki*; Ito, Atsushi*; Minami, Yasuo*; et al.
no journal, ,
no abstracts in English
Hasegawa, Noboru; Nishikino, Masaharu; Tomita, Takuro*; Takei, Ryota*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Hatomi, Daiki*; Onishi, Naofumi*; Baba, Motoyoshi*; Kawachi, Tetsuya; et al.
no journal, ,
We have observed the temporal evolution of the femto-second laser irradiated metal surface by using the soft X-ray laser probe at the wavelength of 13.9 nm. The initial dynamics of the fs-laser ablation is quite rapid ( a few ps) and the dynamics of the laser processing is kept for a long time. We have developed a new pump and probe system to measure these phenomena by the same set-up. By using this system, we have succeeded to obtain the temporal evolution of the ablation front exfoliated from the laser ablated gold surface.
Hasegawa, Noboru; Nishikino, Masaharu; Tomita, Takuro*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Hatomi, Daiki*; Onishi, Naofumi*; Ito, Atsushi*; Minami, Yasuo*; Takei, Ryota*; et al.
no journal, ,
We have observed the temporal evolution of the femto-second laser irradiated metal surface by using the soft X-ray laser probe at the wavelength of 13.9 nm. We have succeeded to obtain the temporal evolution of the ablation front from the result of the soft X-ray reflective imaging and interferogram. We will report about "the Newton's ring generated between the ablation front and the metal surface" and "the ablation front dynamics observed by the soft X-ray shadow graph".
Aoki, Ryota; Sato, Tetsuya; Uchibaba, Yuta; Miyachi, Yuta*; Gong, G.; Natori, Hina*; Ito, Yuta; Asai, Masato; Tsukada, Kazuaki; Nagame, Yuichiro*
no journal, ,
In order to apply the ion beams of superheavy elements with atomic number over 100 to physics and chemistry research, we constructed an EBGP (Electron Beam Generated Plasma) ion source as an ion source applicable to short-lived single atoms. The EBGP ion source was installed in the JAEA-ISOL (Isotope Separator On-Line), and ion beam generation in various ionization conditions has been conducted with several noble gases. As a result, we confirmed the ion source worked in a stable condition, and an ion beam was successfully generated.
Uchibaba, Yuta; Ito, Yuta; Sato, Tetsuya; Aoki, Ryota; Asai, Masato; Gong, G.; Miyachi, Yuta*; Nagame, Yuichiro*; Natori, Hina*; Tsukada, Kazuaki
no journal, ,
In anticipation of precise mass measurement of superheavy nuclei with an atomic number of 104 or more, we are developing an ion trap for the purpose of improving the accuracy of mass determination by prior identification of ions to be measured by decay spectroscopy and correlation with decay information. In order to capture radiation from trapped unstable nuclear ions at a large solid angle, we have developed a vane electrode type ion trap using a thin plate-like vane electrode. As an indication of performance, the trap lifetime and accumulated charge were evaluated in comparison with a circular electrode type ion trap.
Sato, Tetsuya; Aoki, Ryota; Miyachi, Yuta*; Asai, Masato; Ito, Yuta; Uchibaba, Yuta; Gong, G.; Natori, Hina*; Tsukada, Kazuaki; Nagame, Yuichiro*
no journal, ,
We have been developing an EBGP (Electron Beam Generated Plasma) ion source1 coupled to the gas-jet transport system to produce SHE ion beams for rapid chemical experiments. The EBGP ion source ionizes atoms and molecules by electron impact and is expected to produce ion beams of various elements. We have succeeded to produce ion-beams of several noble gases using the present ion source, and it has been found that the beam intensities increase with increasing atomic number. We report on the ionization of various short-lived nuclides produced in spontaneous fission of Cf.